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El lugar más frío de la Tierra está más frío de lo que los científicos pensaban

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El lugar más frío de la Tierra está más frío de lo que los científicos pensaban

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25 June 2018

WASHINGTON - Tiny valleys near the top of Antarctica's ice sheet reach temperatures of nearly minus 100 degrees Celsius (minus 148 degrees Fahrenheit) in the winter, a new study finds. The results could change scientists' understanding of just how low temperatures can get at Earth's surface, according to the researchers.

Scientists announced in 2013 they had found the lowest temperatures on Earth's surface: Sensors on several Earth-observing satellites measured temperatures of minus 93 degrees Celsius (minus 135 degrees Fahrenheit) in several spots on the East Antarctic Plateau, a high snowy plateau in central Antarctica that encompasses the South Pole. But the researchers revised that initial study with new data and found the temperatures actually reach minus 98 degrees Celsius (minus 144 degrees Fahrenheit) during the southern polar night, mostly during July and August.

When the researchers first announced they had found the coldest temperatures on Earth five years ago, they determined that persistent clear skies and light winds are required for temperatures to dip this low. But the new study adds a twist to the story: Not only are clear skies necessary, but the air must also be extremely dry, because water vapor traps some heat in the air.

The researchers observed the ultra-low temperatures in small dips or hollows in the Antarctic Ice Sheet. The super cold, super dry air is denser than the slightly warmer air around it, so it falls into the hollows and becomes trapped. This allows the snow surface and the air above it to cool further, until the clear, calm, dry conditions change and the cold air mixes with warmer air higher in the atmosphere.

"In this area, we see periods of incredibly dry air, and this allows the heat from the surface of the snow to radiate into space more easily," said Ted Scambos, a senior research scientist at the National Snow and Ice Data Center at the University of Colorado-Boulder and lead author of the new study in Geophysical Research Letters, a journal of the American Geophysical Union.

The record of minus 98 degrees Celsius is about as cold as it is possible to get at Earth's surface, according to the researchers. For the temperature to drop that low, clear skies and dry air need to persist for several days. Temperatures could drop a little lower if the conditions lasted for several weeks, but that's extremely unlikely to happen, Scambos said.
Finding the coldest place
The high elevation of the East Antarctic Plateau and its proximity to the South Pole give it the coldest climate of any region on Earth. The lowest air temperature ever measured by a weather station, minus 89 degrees Celsius (minus 128 degrees Fahrenheit), was recorded there at Russia's Vostok Station in July 1983.

But weather stations can't measure temperatures everywhere. So in 2013, Scambos and his colleagues decided to analyze data from several Earth-observing satellites to see if they could find temperatures on the plateau even lower than those recorded at Vostok.

In the new study, they analyzed satellite data collected during the Southern Hemisphere's winter between 2004 and 2016. They used data from the MODIS instrument aboard NASA's Terra and Aqua satellites as well as data from instruments on NOAA's Polar Operational Environmental Satellites.

The researchers initially saw a broad region of the plateau more than 3,500 meters (11,000 feet) above sea level where temperatures regularly dropped below minus 90 degrees Celsius (minus 130 degrees Fahrenheit) at the snow surface. The lowest temperature they observed was minus 93 degrees Celsius (minus 135 degrees Fahrenheit).

Data from the MODIS instruments is calibrated using temperature measurements from weather stations on the ground. In 2016, NASA recalibrated the MODIS data with more up-to-date weather station measurements, and the researchers reanalyzed the temperature data. The weather conditions on the plateau did not change, but the adjusted satellite data gave the researchers a more accurate picture of what the actual lowest temperature was.

They found the record low was about 5 degrees Celsius (9 degrees Fahrenheit) colder than they originally reported, about minus 98 degrees Celsius (minus 144 degrees Fahrenheit).
How cold can it get?
Scambos and his colleagues analyzed the terrain where they saw these ultra-low temperatures and found they occurred in small hollows 2 to 3 meters (6 to 9 feet) deep in the surface of the ice, on the southern side of high ridges on the plateau.

Interestingly, the researchers noticed a whole cluster of places where temperatures plunged almost exactly to that record low over the 14-year period, even though they were located hundreds of kilometers apart. That got them wondering: Is there a limit to how cold it can get on the plateau?

For the temperature to drop to that record low, skies must be clear and the air must be bone-dry for several days. After the temperature drops below a certain point, the air cools so slowly that it can't get perceptibly colder before the weather conditions change, according to the researchers. Minus 98 degrees Celsius, then, appears to be the limit to how cold it can get at Earth's surface, Scambos said.

"There's a limit to how long the conditions persist to allow it to cool to these ultra-low temperatures, and a limit to how much heat you can actually get through the atmosphere, because water vapor has to be almost nonexistent in order to emit heat from the surface at these temperatures," he said.

The research team has developed a set of instruments designed to survive and operate at the very coldest places throughout the winter to measure both snow and air temperatures. They are planning to deploy the instruments within the next two years.

###

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Title

"Ultra-low surface temperatures in East Antarctica from satellite thermal infrared mapping: the coldest places on Earth"

Authors:
Ted A. Scambos, G. G. Campbell, A. Pope, T. Haran: National Snow and Ice Data Center, University of Colorado at Boulder, Boulder, Colorado, U.S.A.;

A. Muto: Department of Earth and Environmental Science, Temple University, Philadelphia, Pennsylvania, U.S.A.;

M. Lazzara: Antarctic Meteorological Research Center, University of Wisconsin-Madison and Madison Area Technical College, Madison, Wisconsin, U.S.A.;

C. H. Reijmer, M. R. van den Broeke: Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, Netherlands.

Contact information for the authors:
Ted A. Scambos: [email protected] , +1 (303) 492-1113

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Coldest place on Earth is colder that scientists thought

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Tiny valleys near the top of Antarctica's ice sheet reach cold temperatures of nearly minus 100 degrees Celsius (minus 148 degrees Fahrenheit) in the winter, a new study finds. The results could change scientists' understanding of just how low temperatures can get at Earth's surface, according to the researchers.

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Una prueba galáctica que clarificará la existencia de la materia obscura

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Una prueba galáctica que clarificará la existencia de la materia obscura

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Researchers at the University of Bonn and the University of California at Irvine used sophisticated computer simulations to devise a test that could answer a burning question in astrophysics: is there really dark matter? Or does Newton's gravitational law need to be modified? The new study, now published in the Physical Review Letters, shows that the answer is hidden in the motion of the stars within small satellite galaxies swirling around the Milky Way.

Using one of the fastest supercomputers in the world, the scientists have simulated the matter distribution of the so-called satellite "dwarf" galaxies. These are small galaxies that surround, for instance, the Milky Way or Andromeda.

The researchers focused on a relationship called "radial acceleration relation" (RAR). In disk galaxies, stars move in circular orbits around the galactic center. The acceleration that forces them to constantly change direction is caused by the attraction of matter in the galaxy. The RAR describes the relationship between this acceleration and the one caused by the visible matter only. It provides an insight into the structure of galaxies and their matter distribution.

"We have now simulated, for the first time, the RAR of dwarf galaxies on the assumption that dark matter exists," explains Prof. Dr. Cristiano Porciani of the Argelander Institute for Astronomy at the University of Bonn. "It turned out that they behave as scaled-down versions of larger galaxies." But what if there is no dark matter and instead gravity "works" differently than Newton thought? "In this case the RAR of dwarf galaxies depends strongly on the distance to their parent galaxy, while this does not happen if dark matter exists", explains the researcher Emilio Romano-Díaz.

This difference makes the satellites a powerful probe for testing whether dark matter really exists. The Gaia spacecraft, which was launched by the European Space Agency (ESA) in 2013, could already provide an answer. It was designed to study the stars in the Milky Way and its satellite galaxies in unprecedented detail and has collected a large amount of data.

However, it will probably take years to solve this riddle. "Individual measurements are not enough to test the small differences we have found in our simulations", explains doctoral student Enrico Garaldi. "But repeatedly taking a close look at the same stars improves the measurements every time. Sooner or later it should be possible to determine whether the dwarf galaxies behave like in a universe with dark matter - or not."
The cement that holds galaxies together
This question is one of the most pressing issues in cosmology today. The existence of dark matter was already suggested more than 80 years ago by the Swiss astronomer Fritz Zwicky. He realized that galaxies move so fast within galaxy clusters that they should actually drift apart. He therefore postulated the presence of invisible matter which, due to its mass, exerts sufficient gravity to keep galaxies on their observed orbits. In the 1970s, his US colleague Vera Rubin discovered a similar phenomenon in spiral galaxies like the Milky Way: they rotate so quickly that the centrifugal force should tear them apart if only visible matter was present.

Today, most physicists are convinced that dark matter makes up about 80 percent of the mass in the universe. Since it does not interact with light, it is invisible to telescopes. Yet, assuming its existence provides an excellent fit to a number of other observations - such as the distribution of background radiation, an afterglow of the Big Bang. Dark matter also provides a good explanation for the arrangement and formation rate of galaxies in the universe. However, despite numerous experimental efforts, there is no direct proof that dark matter exists. This led astronomers to the hypothesis that the gravitational force itself might behave differently than previously thought. According to the theory called MOND (MOdified Newtonian Dynamics), the attraction between two masses obeys Newton's laws only up to a certain point. At very small accelerations, such as those prevailing in galaxies, gravity becomes considerably stronger. Therefore, galaxies do not tear apart due to their rotational speed and the MOND theory can dispense with the mysterious star putty.

The new study opens up the possibility for astronomers to test these two hypotheses in an unprecedented regime.

The project was funded by the German Research Foundation (DFG) through TR333 and SFB956. The calculations were made possible by the Europe-wide PRACE network and were carried out on the Dutch supercomputer Cartesius, at SURFsara, The Netherlands.

Publication: Enrico Garaldi, Emilio Romano-Díaz, Cristiano Porciani and Marcel S. Pawlowski: Radial acceleration relation of ΛCDM satellite galaxies; Physical Review Letters; DOI: 10.1103/PhysRevLett.120.261301

Contacts:

Prof. Dr. Cristiano Porciani
Argelander-Institut für Astronomie der Universität Bonn
Tel.:+49 (0) 228 733664
E-mail: cporcian@uni-bonn.de

Dr. Emilio Romano-Díaz
Argelander-Institut für Astronomie der Universität Bonn
Tel.:+49 (0) 228 733657
E-mail: emiliord@uni-bonn.de

Enrico Garaldi
Argelander-Institut für Astronomie der Universität Bonn
Tel.: +49 (0) 228 733433
E-mail: egaraldi@uni-bonn.de

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A galactic test will clarify the existence of dark matter - Universität Bonn

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Researchers at the University of Bonn and the University of California at Irvine used sophisticated computer simulations to devise a test that could answer a burning question in astrophysics: is there really dark matter? Or does Newton's gravitational law need to be modified?

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Evolución en 3 fases de un Hoyo Coronal, Parte I: 360o de sensado remoto y observaciones in-situ

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Evolución en 3 fases de un Hoyo Coronal, Parte I: 360o de sensado remoto y observaciones in-situ

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Deadly Storms, Colder, Galactic Gamma Bubble | S0 News Jun.26.2018

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Un análisis de los datos de los Satélites Swarm muestran anomalías sismo-ionosféricas alrededor de la hora del fuerte terremoto M8.2 en México del 08.Sep.2017

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Un análisis de los datos de los Satélites Swarm muestran anomalías sismo-ionosféricas alrededor de la hora del fuerte terremoto M8.2 en México del 08.Sep.2017

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Analysis of Swarm satellites data showing seismo-ionospheric anomalies around the time of the strong Mexico (Mw = 8.2) earthquake of 08 September 2017

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In 98 km SW of TresPicosin Mexico (15.022 N, 93.899 W, 47.40 km depth) a powerful earthquake of Mw = 8.2 happened at 23:49:19 LT on September 07 (04:4...

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Clima Espacial, Tormentas Electricas, Confirmación México

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Clima Espacial, Tormentas Electricas, Confirmación México

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Space Weather, Lightning, Mexico Confirmation | S0 News Jun.25.2018

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Ciclos de calor en el océano muestran que el carbono atmosférico  podría venir de otro lugar.

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Ciclos de calor en el océano muestran que el carbono atmosférico  podría venir de otro lugar.

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As humans continue to pump the atmosphere with carbon, it's crucial for scientists to understand how and where the planet absorbs and naturally emits carbon.

A recent study in the journal Nature Geoscience examined the global carbon cycle and suggests that existing studies may have misgauged how carbon is distributed around the world, particularly between the northern and southern hemispheres. The results could change projections of how, when and where the currently massive levels of atmospheric carbon will result in environmental changes such as ocean acidification.

By re-examining ocean circulations and considering the carbon-moving power of rivers, the study's authors suggest that as much as 40 percent of the world's atmospheric carbon absorbed by land needs to be reallocated from existing estimates. In particular, the Southern Ocean encircling Antarctica and forests in the northern hemisphere - while still substantial absorbers or "sinks" of carbon - may not take up as much as scientists have figured.

"The carbon story we got is more consistent with what people have observed on the ground," said first author Laure Resplandy, an assistant professor of geosciences and the Princeton Environmental Institute at Princeton University.

"Rivers have been largely overlooked," Resplandy said. "We need to better constrain the transport of carbon from the land to the ocean by rivers. Otherwise, this carbon is attributed to the land sink and is missing from the ocean sink. If carbon goes into the land or into the ocean, it doesn't have the same impact."

Resplandy and her co-authors used models and field observations to find that the world's oceans transport heat between the northern and southern hemispheres in the same way that carbon is transported. The transport of heat, however, is easier to observe. By tracking this heat, the researchers discovered that the ocean in the southern hemisphere is a much smaller carbon sink than previously thought and that the land at the same latitude is an almost non-existent source of carbon.

At the same time, the land in the northern hemisphere is a much smaller sink, meaning that it absorbs less carbon than climate models had accounted for. Instead, the researchers found that this carbon is sent to the ocean by rivers and transported to the southern hemisphere by ocean currents with 20 to 100 percent more strength than previous studies and models had shown.

For scientists, the world's carbon "budget" is like a bank ledger, Resplandy said. The carbon being absorbed into the global cycle needs to match the carbon being emitted. While the ocean carbon cycle is well documented, direct observations of carbon flux on land are difficult to obtain and are influenced by numerous factors. As a result, the extent to which land acts as a sink or source is largely deduced by assigning it whatever carbon is left over after ocean data are considered, Resplandy said.

"In the southern hemisphere, the ocean sink was overestimated. As a result, the land, which is deduced from observed atmospheric carbon dioxide and the assumed ocean sink in the same region, was found to be a source," Resplandy said.

"This was highly surprising though as there is not a lot of land mass in the southern hemisphere to sustain this source," she said. "Our new estimate reconciles this apparent discrepancy by suggesting that there is a weaker ocean sink and close-to-zero land flux in the south."

In a commentary about the paper published in Nature Geoscience, Andrew Lenton, a research scientist at the Centre for Southern Hemisphere Oceans Research in Australia, wrote that the researchers established a correlation between heat and carbon transport, and showed that the pre-industrial carbon cycle can inform the understanding of the cycle today.

The researchers "provided an important baseline for understanding and attributing changes in land and ocean sinks in response to increasing atmospheric CO 2 concentrations," Lenton wrote. "Their results demonstrate the importance of the pre-industrial carbon cycle in setting the distribution of carbon sinks in the present day, and the power of exploiting the relationship between ocean heat and carbon transport driven by large-scale circulation."

Scientists need to know how much carbon is entering the oceans, and where, so that they can more accurately project environmental changes that have a global reach, Resplandy said. Oceans, especially in the southern hemisphere, naturally take up carbon and heat from the atmosphere. But the price paid is a warmer ocean and higher acidity that threatens marine life and sea-based economies such as fishing.

"Now it matters to do a better job understanding the ocean," Resplandy said. "Our main point is that carbon gets redistributed because it was wrongly allocated. A lot of people had different pieces, but all the pieces weren't quite fitting together."

Resplandy worked on the study with Ralph Keeling, a professor and program director at the Scripps Institution of Oceanography at the University of California-San Diego; Christian Rödenbeck, a research scientist at the Max Planck Institute for Biogeochemistry in Germany; Briton Stephens and Matthew Long, scientists at the National Center for Atmospheric Research; Samar Khatiwala, professor of Earth sciences at the University of Oxford; Keith Rodgers, a research oceanographer in Princeton's Program in Atmospheric and Oceanic Sciences; Laurent Bopp, director of CNRS at Ecole Polytechnique/Sorbonne Université in Paris; and Pieter Tans, chief of the Carbon Cycle Greenhouse Gases Group at NOAA's Earth System Research Laboratory.
The paper, "Revision of global carbon fluxes based on a reassessment of oceanic and riverine carbon transport," was published online in advance of print June 11 by Nature Geoscience. This work was supported by the National Oceanic and Atmospheric Administration's Climate Program Office (grant no. NA13OAR4310219); the National Science Foundation (grant no. OCE 10-60804); and NASA (award no. NNX14AL85G).

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Ocean's heat cycle shows that atmospheric carbon may be headed elsewhere

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As humans continue to pump the atmosphere with carbon, it's crucial for scientists to understand how and where the planet absorbs and naturally emits carbon. A recent study in the journal Nature Geoscience examined the global carbon cycle and suggests that existing studies may have misgauged how carbon is distributed around the world, particularly between the northern and southern hemispheres.

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El Proyecto Dark y la estructura bariónica elipsoidal de Clusters de Galaxias 20 Clash

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El Proyecto Dark y la estructura bariónica elipsoidal de Clusters de Galaxias 20 Clash

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Asegurando el combustible para nuestro futuro cósmico glacial

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Asegurando el combustible para nuestro futuro cósmico glacial

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Un Amplificador de Tres-Fases del Campo Magnético Cósmico en las Galaxias

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Un Amplificador de Tres-Fases del Campo Magnético Cósmico en las Galaxias

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Observaciones de bariones perdidos en un medio intergaláctico caliente-templado

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Observaciones de bariones perdidos en un medio intergaláctico caliente-templado

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Additional information

Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

References

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Planck Collaboration. Planck 2015 results. XIII. Cosmological parameters. Astron. Astrophys. 594, A13 (2016).

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Mernier, F. et al. Radial metal abundance profiles in the intra-cluster medium of cool-core galaxy clusters, groups, and ellipticals. Astron. Astrophys. 603, A80 (2017).

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Acknowledgements

This work is based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. F.N. and M.E. acknowledge support from NASA grant NNX17AD76G. S.M. acknowledges NASA grant NNX16AF49G. S.B. acknowledges financial support through agreement ASI-INAF n.2017-14-H.0 and an INFN INDARK grant. Y.K. thanks INAOE for the support offered during a sabbatical visit in 2017 and acknowledges support from grant DGAPA-PAPIIT 106518 and from programme DGAPA-PASPA. R.C. acknowledges support from NSF grant AST-1515389.

Reviewer information

Nature thanks R. Davé and T. Fang for their contribution to the peer review of this work.

Author information

Affiliations

Istituto Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Roma, Rome, Italy

Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA

Department of Astrophysical Science, University of Colorado, Boulder, CO, USA

Instituto Nacional de Astrofísica, Óptica y Electrónica, Puebla, Mexico

D. Mayya

& D. Rosa-Gonzalez

Leiden Observatory, Leiden, The Netherlands

Contributions

F.N. designed the study (together with J.K., L.P., S.B., L.Z., S.M., M.E., R.C., F.P. and A.G.), reduced and analysed the X-ray data, analysed the FUV data, extracted diagnostics by modelling the X-ray and FUV data and wrote the paper. Y.K., J.K., L.P., S.M., M.E., F.P., F.F. and A.G. helped with the analysis and modelling of the X-ray spectra. M.D. and F.N. designed and executed the Monte Carlo simulations used to evaluate the statistical significance of the absorbers. J.K. provided the most up-to-date XMM-Newton RGS calibrations and effective area corrections. C.W.D. and J.M.S. reduced the HST-COS data, extracted the G130 and G160 final spectra and helped with the interpretation of those spectra. Y.K. performed the optical photometric observations, as well as the reduction and analysis of those data, with the help of D.M. and D.R.-G. D.R.-G. and J.T.Z. provided the galaxies' spectroscopic redshifts. S.B., E.B., J.S., N.W. and R.C. provided hydrodynamical simulations and general theoretical support to the results. In particular, J.S. and N.W. provided results from high-resolution Eagle simulations and F.P. helped to extract the number density of O vii absorbers from these simulations. All authors contributed equally to the discussion of the results and commented on the manuscript.

Competing interests

The authors declare no competing interests.

Corresponding author

Correspondence to F. Nicastro.

Extended data figures and tables

Broadband, unfolded RGS1 (black points; 1 σ error bars) and RGS2 (red points; 1 σ error bars) spectra (in bins with a signal-to-noise ratio per bin ≥20) and best-fitting models (black and red histograms) for the blazar 1ES 1553+113, in physical units. Blue arrows mark Galactic absorption lines; green and magenta arrows indicate absorption lines from our WHIM System 1 and System 2, respectively. F E, source flux (power per unit area and energy).

Normalized raw RGS1 (black points; 1 σ error bars) and RGS2 (red points; 1 σ error bars) data (in bins with a signal-to-noise ratio per bin ≥30) of the blazar 1ES 1553+113, in the wavelength interval λ = 26−32 Å. Thick dashed curves are the RGS1 (black) and RGS2 (red) best-fitting models, folded through the response functions of the RGSs. Thin solid curves at the bottom of the graph are RGS1 (black) and RGS2 (red) effective areas (in arbitrary units), showing instrumental features due to cool pixels in the dispersing detectors. Of the five absorption lines shown, only the weak O vii Heβ at z X  =  0.4339, and only in RGS1, can be affected by the presence of an instrumental feature.

Outcome of a Monte Carlo procedure consisting of 10,000 evaluations of the single-line statistical significance of an unresolved (that is, broadened to the instrument line spread function) Gaussian added to the best-fitting continuum-plus-line model of the RGS spectrum of 1ES 1553+113 (see Methods). At each run, the line position is frozen at a random position in the range 8-33 Å, and its EW is allowed to vary freely from negative (emission) to positive (absorption). The data distribution is symmetric but slightly flatter than the red curve that shows the expected normal distribution for a standard deviation of unity. The normal distribution that best fits our Monte Carlo results has a standard deviation of 1.15 (green curve).

a, b, RGS spectra of 1ES 1553+113 obtained in the 2015 (black) and 2017 (red) observations for 800 ks and 950 ks, respectively, centred around the O vii Heα ( a) and Heβ ( b) transitions of System 1. The two lines are consistent with no variability between the two epochs, within their 1 σ errors (Extended Data Table 2).

Histogram of photometric redshifts of r′ > 23.5 galaxies within cylindrical volumes with base radii of 500 kpc at each redshift interval and a line-of-sight depth of Δ z = 0.075 (at 1 σ redshift accuracy), centred on the line of sight to the blazar 1ES 1553+113. The black curve is the average number of galaxies with r′ > 23.5 expected within the explored volumes at each redshift bin, based on the galaxy log N-log S from ref. (where N is the number of galaxies with surface brightness ≥ S and we use a common but conservative B−r′ = 1 for all galaxy types, where B is the galaxy's B magnitude). Vertical dashed green and blue lines indicate the redshifts of System 1 and System 2, respectively.

OSIRIS-GTC mosaic (in band r′) of the 12′ × 12′ field surrounding the line of sight to 1ES 1553+113 (indicated by the magenta circle). Green circles have radii of 500 kpc and 1.75 Mpc at z = 0.4125. Thin yellow circles highlight the positions of galaxies with photometric redshift estimates within the z  = 0.375-0.450 interval, whereas thicker circles highlight spectroscopic redshifts (solid, confirmed; dashed, unconfirmed).

Same as Extended Data Fig. 5, but for System 2, in the z  = 0.300-0.375 interval.

Extended Data Table 1 Absorption lines of System 1 and System 2

Extended Data Table 2 Lack of variability of the O vii absorbers over two years

Extended Data Table 3 Physics and chemistry of System 1 and System 2

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# data[].attributes.attachment_link.title
Observations of the missing baryons in the warm-hot intergalactic medium

# data[].attributes.attachment_link.description
Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. 4. Planck Collaboration. Planck 2015 results. XIII. Cosmological parameters. Astron. Astrophys. 594, A13 (2016). 15. Mernier, F. et al. Radial metal abundance profiles in the intra-cluster medium of cool-core galaxy clusters, groups, and ellipticals.

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After a nearly twenty-year long game of cosmic hide-and-seek, astronomers using ESA's XMM-Newton space observatory have finally found evidence of hot, diffuse gas permeating the cosmos, closing a puzzling gap in the overall budget of 'normal' matter in the Universe.

While the mysterious dark matter and dark energy make up about 25 and 70 percent of our cosmos respectively, the ordinary matter that makes up everything we see - from stars and galaxies to planets and people - amounts to only about five percent.

But even this five percent turns out to be quite hard to track down.

The total amount of ordinary matter, which astronomers refer to as baryons, can be estimated from observations of the Cosmic Microwave Background, which is the most ancient light in the history of the Universe, dating back to only about 380 000 years after the Big Bang.

Observations of very distant galaxies allow astronomers to follow the evolution of this matter throughout the Universe's first couple billions of years. After that, however, more than half of it seemed to have gone missing.

"The missing baryons represent one of the biggest mysteries in modern astrophysics," explains Fabrizio Nicastro, lead author of the paper presenting a solution to the mystery, published today in Nature.

"We know this matter must be out there, we see it in the early Universe, but then we can no longer get hold of it. Where did it go?"

Counting the population of stars in galaxies across the Universe, plus the interstellar gas that permeates galaxies - the raw material to create stars - only gets as far as a mere ten percent of all ordinary matter. Adding up the hot, diffuse gas in the haloes that encompass galaxies and the even hotter gas that fills galaxy clusters, which are the largest cosmic structures held together by gravity, raises the inventory to less than twenty percent.

This is not surprising: stars, galaxies and galaxy clusters form in the densest knots of the cosmic web, the filamentary distribution of both dark and ordinary matter that extends throughout the Universe. While these sites are dense, they are also rare, so not the best spots to look for the majority of cosmic matter.

Astronomers suspected that the 'missing' baryons must be lurking in the ubiquitous filaments of this cosmic web, where matter is however less dense and therefore more challenging to observe. Using different techniques over the years, they were able to locate a good chunk of this intergalactic material - mainly its cool and warm components - bringing up the total budget to a respectable 60 percent, but leaving the overall mystery still unsolved.

Fabrizio and many other astronomers around the world have been on the tracks of the remaining baryons for almost two decades, ever since X-ray observatories such as ESA's XMM-Newton and NASA's Chandra became available to the scientific community.

Observing in this portion of the electromagnetic spectrum, they can detect hot intergalactic gas, with temperatures around a million degrees or more, that is blocking the X-rays emitted by even more distant sources.

For this project, Fabrizio and his collaborators used XMM-Newton to look at a quasar - a massive galaxy with a supermassive black hole at its centre that is actively devouring matter and shining brightly from X-rays to radio waves. They observed this quasar, whose light takes more than four billion years to reach us, for a total of 18 days, split between 2015 and 2017, in the longest X-ray observation ever performed of such a source.

"After combing through the data, we succeeded at finding the signature of oxygen in the hot intergalactic gas between us and the distant quasar, at two different locations along the line of sight," says Fabrizio.

"This is happening because there are huge reservoirs of material - including oxygen - lying there, and just in the amount we were expecting, so we finally can close the gap in the baryon budget of the Universe."

This extraordinary result is the beginning of a new quest. Observations of different sources across the sky are needed to confirm whether these findings are truly universal, and to further investigate the physical state of this long-sought-for matter.

Fabrizio and his colleagues are planning to study more quasars with XMM-Newton and Chandra in the coming years. To fully explore the distribution and properties of this so-called warm-hot intergalactic medium, however, more sensitive instruments will be needed, like ESA's Athena, the Advanced Telescope for High-Energy Astrophysics, scheduled for launch in 2028.

"The discovery of the missing baryons with XMM-Newton is the exciting first step to fully characterise the circumstances and structures in which these baryons are found," says co-author Jelle Kaastra from the Netherlands Institute for Space Research.

"For the next steps, we will need the much higher sensitivity of Athena, which has the study of the warm-hot intergalactic medium as one of its main goals, to improve our understanding of how structures grow in the history of the Universe."

"It makes us very proud that XMM-Newton was able to discover the weak signal of this long elusive material, hidden in a million-degree hot fog that extends through intergalactic space for hundreds of thousands of light years," says Norbert Schartel, XMM-Newton project scientist at ESA.

"Now that we know these baryons are no longer missing, we can't wait to study them in greater detail."

Notes for editors
"Observations of the missing baryons in the warm-hot intergalactic medium" by F. Nicastro et al is published in Nature. DOI: 10.1038/s41586-018-0204-1

For more information, please contact:

Fabrizio Nicastro
Istituto Nazionale di Astrofisica (INAF)
Osservatorio Astronomico di Roma, Italy
Harvard-Smithsonian Center for Astrophysics
Cambridge, MA, USA
Email: fabrizio.nicastro@inaf.it

Jelle S. Kaastra
SRON - Netherlands Institute for Space Research
Utrecht, The Netherlands
Email: J.S.Kaastra@sron.nl

Norbert Schartel
XMM-Newton Project Scientist
European Space Agency
Email: norbert.schartel@esa.int

Markus Bauer
ESA Science Communication Officer
Tel: +31 71 565 6799
Mob: +31 61 594 3 954
Email: markus.bauer@esa.int

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XMM-Newton finds missing intergalactic material

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After a nearly twenty-year long game of cosmic hide-and-seek, astronomers using ESA's XMM-Newton space observatory have finally found evidence of hot, diffuse gas permeating the cosmos, closing a puzzling gap in the overall budget of 'normal' matter in the Universe.

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El hábitat completo se está yendo: las maravillas naturales de Hawái son reclamadas por la lava.

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El hábitat completo se está yendo: las maravillas naturales de Hawái son reclamadas por la lava.

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n Puna, the area of Hawaii island that's been hardest hit by the Kilauea volcano eruption, those who lived nearest to the lava flows watched the forest around their homes begin to die first. They said the fruit trees, flowers and ferns began turning brown, languishing in the noxious, sulfur-dioxide-filled air. Then the lava came. Now large swaths of formerly verdant forest have been replaced by rough and barren volcanic terrain.

"Before the eruptions, that area was probably the best forest left in the state of Hawaii," said Patrick Hart, a biology professor at the University of Hawaii at Hilo. "There were areas where the native Ohia forest extended right up to the ocean, and you just don't see that in the rest of Hawaii," he said. Now it's covered with 20 to 30ft of lava.

Scenes from Pahoa, Hawaii, where the volcanic lava claimed homes, smothered roads and destroyed landscapes

On Hawaii island, also known as the Big Island, lava from the weeks-long eruption of the Kilauea volcano has also paved over tide pools and coral gardens, boiled a 400-year-old lake until it evaporated and killed a number of sea creatures.

But to scientists, it's just part of life on the state's youngest island, where land is still being created as lava continuously reshapes the natural environment.

"From a human point of view, what's happening is tragic," said David Damby, a volcanologist with the United States Geological Survey (USGS). "But from the volcano's point of view, that's the job she does: to build new land and change the landscape. That's the way the earth works."

The humid, rainy forests in Puna were an important habitat for native Hawaiian trees, birds and insects, Hart said. Chartreuse-colored 'amakihis and bright red 'apapanes rested on trees, Hawaiian hawks soared through the air, and dragonflies, butterflies and crickets all made the forest their home.

It will likely take at least 100 years for the decimated tracts of lava-covered forest to begin again - first with lichen, then with native ferns and Ohia trees that have adapted to grow on lava. In 150 years, Hart said, the land could begin to resemble a forest like the one that used to be there. It's a process that has happened many times before on Hawaii.

"It's a very powerful thing to witness," said Ryan Perroy, a volcanologist and associate professor at the University of Hawaii at Hilo. "But in geological terms, it's also not an unexpected event. This is how Puna was built, with volcanic eruptions."

Elsewhere in Puna, there have been other dramatic changes to the landscape. On the morning of 2 June, lava poured into Green Lake. Plumes of steam began rising from the popular swimming spot where depths reached about 200ft; in less than two hours, the 400-year-old freshwater lake was gone - evaporated and covered in lava.

Just days later, rivers of lava flowed into nearby Kapoho Bay, destroying hundreds of homes and paving over the turquoise, coral-filled bay and a series of rare, protected tide pools that had teemed with marine life.

There was no place like Kapoho in all of Hawaii

John Burns, scientist

"Kapoho Bay was a very important recreational place for people in this area," said Steven Colbert, an associate professor in marine science at the University of Hawaii at Hilo. "There aren't a lot of places here where you can access the shoreline and get in the water easily. And this was one of those areas. It was also a very important research spot for us scientists."

The tide pools at Kapoho Bay, Colbert said, were home to thriving coral and abundant fish - especially small ones that found safe haven from predators in the protected environment. When the lava entered the ocean there, much of the marine life was covered or boiled alive.

"For the animals right there when the lava reaches the water, they don't have a chance," he said.

In the meantime, the surrounding water will need to clear, but that won't happen until the eruption slows or stops.

"It's gone from beautiful Hawaiian water that is clear and turquoise, where you can see 50 to 60ft down, to a muddy mess filled with volcanic glass particles," he said. "It blots out the sunlight so normal algae can't grow, and filter feeders like coral have to sort between bits of food and volcanic particles."

The loss to scientists has been great. "There was no place like Kapoho in all of Hawaii," said John Burns, who spent a decade studying coral in the tide pools, said. "That entire habitat is gone now." Once the glassy volcanic particles dissipate and the PH and temperature of the water returns to normal, he said, the coral can begin to regrow. But it will be starting from scratch, just as part of that area did when it was formed by lava in the 1950s and 1960s. How fast the coral regrow will depend on whether the lava creates a sloping coastline, or protected pools like it did in Kapoho, which can allow for faster growth than the usual rate of one centimeter per-year.

"In terms of marine organisms and coral, we're basically starting from day one now." And yet, he said, it's easier to lose an irreplaceable reef to lava than it is to lose it to bleaching, which has happened in many places in Hawaii because of a global rise in ocean temperatures.

"There's the tragedy of people losing their homes and for us, as scientists, losing our research site. But from the perspective of the environment, this is a natural cycle," he said. "I'd much rather see a reef die from lava than from bleaching."

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'The entire habitat is gone': Hawaii's natural wonders claimed by lava

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n Puna, the area of Hawaii island that's been hardest hit by the Kilauea volcano eruption, those who lived nearest to the lava flows watched the forest around their homes begin to die first. They said the fruit trees, flowers and ferns began turning brown, languishing in the noxious, sulfur-dioxide-filled air.

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VLT hace la Prueba más Precisa de la Ley de Relatividad General de Einstein fuera de la Vía Láctea

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VLT hace la Prueba más Precisa de la Ley de Relatividad General de Einstein fuera de la Vía Láctea

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VLT Makes Most Precise Test of Einstein's General Relativity Outside Milky Way

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Astronomers using the MUSE instrument on ESO's Very Large Telescope in Chile, and the NASA/ESA Hubble Space Telescope, have made the most precise test yet of Einstein's general theory of relativity outside the Milky Way. The nearby galaxy ESO 325-G004 acts as a strong gravitational lens, distorting light from a distant galaxy behind it to create an Einstein ring around its centre.

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An international research team, led by Dr. Ruobing Dong at University of Arizona in USA and in Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan, has discovered the tale-telling signs of planets in the young, likely planet-forming disk around the star MWC 758. Obtained with the Atacama Large Millimeter and submillimeter Array (ALMA), the "ultra" high resolution image revealed the disk having not only an off-centered cavity but also a spiral arm corresponding to one previously seen in reflected light.

"What drives the various kinds of structures we see in planet forming young disks around protostars? This is a question that has baffled astronomers for over a decade!", pointed out by Dr. Dong, "Our observations reveal a great amount of exciting new details in this system and provide crucial clues on their origins."

Since the early 2000, rich structures, including gaps and rings, dust clumps, and spiral arm-like features, have been discovered in a few tens of disks surrounding newborn stars. With the belief that planets are forming inside, astronomers named these disks "protoplanetary disks".

The origin of these structures is in hot debate among astronomers. In one scenario, they are thought to be produced by unseen planets forming inside and gravitationally interacting with the host disks, as planets open gaps, shepherd dust clumps, and excite spiral arms.

Alternative ways to produce observed disk structures that do not invoke planets have also been raised. For examples, large central cavities may be the outcome of photoevaporation, as high energy radiations from the central star evaporate the inner disk. Also, under certain conditions shadows in disks may mimic the spiral arms seen in reflected light.

The protoplanetary disk around a young star MWC 758 is located at 500 light years from us. In 2012, a pair of near symmetric giant spiral arms was discovered in reflected light. In dust thermal and molecular gas line emission at millimeter wavelengths, a big inner hole and two major dust clumps have been found, too.

Now with the new ALMA image, the previously known cavity of MWC 758 is shown to be off-centered from the star with its shape well described by an ellipse with one focus on the star. Also, a millimeter dust emission feature corresponds nicely with one of the two spiral arms previously seen in reflected light. Both discoveries are the first among protoplanetary disks.

"MWC 758 is a rare breed!", says Dr. Sheng-Yuan Liu at ASIAA, "All major types of disk structures have been found in this system. It reveals to us one of the most comprehensive suites of evidence of planet formation in all protoplanetary disks."

Previously in 2015, Dr. Dong and his collaborators proposed that the two arms in the MWC 758 disk can be explained as driven by a super-Jupiter planet just outside the disk.

"Our new ALMA observations lend crucial support to planet-based origins for all the structures.", says Dr. Takayuki Muto at Kogakuin University, Japan, "For example, it's exciting to see ellipses with one focus on the star - that's Kepler's first law! It's pointing to a dynamical origin, possibly interactions with planets."

The off-centered cavity strongly, on the other hand, disfavors alternative explanations such as photoevaporation, which do not have an azimuthal dependence.

The fact that the south spiral arm is present in the millimeter emission tracing the dust rules that the arm is a density arm. Other scenarios, such as shadows, which view the spiral arms as surface features, are not expected to reproduce the observations. The ultra-high resolution achieved in the new ALMA dataset also enables the detection of a slight offset between the arm locations in reflected light and in dust emission, which is consistent with models of planet-induced density wave.

"These fantastic new details are only made possible thanks to the amazing angular resolution delivered by ALMA", says Dr. Eiji Akiyama at Hokkaido University, Japan, "We took full advantage of ALMA's long baseline capabilities, and now the MWC 758 disk joins the elite club of "ultra-high resolution ALMA disks" alongside only a handful of others."
Paper and research team
This research was presented in a paper "The Eccentric Cavity, Triple Rings, Two-Armed Spirals, and Double Clumps of the MWC 758 Disk" by Dong et al. to appear in the Astrophysical Journal.

The team is composed of Ruobing Dong (U. of Arizona, USA; ASIAA, Taiwan), Sheng-yuan Liu (ASIAA, Taiwan), Josh Eisner (University of Arizona, USA), Sean Andrews (Harvard-Smithsonian Center for Astrophysics, USA), Jeffrey Fung (UC Berkeley, USA), Zhaohuan Zhu (UNLV, USA) Eugene Chiang (UC Berkeley, USA), Jun Hashimoto (Astrobiology Center, NINS, Japan), Hauyu Baobab Liu (European Southern Observatory, Germany), Simon Casassus (University of Chile, Chile), Thomas Esposito (UC Berkeley, USA), Yasuhiro Hasegawa (JPL/Caltech, USA), Takayuki Muto (Kogakuin University, Japan), Yaroslav Pavlyuchenkov (Russian Academy of Sciences, Russia), David Wilner (Harvard-Smithsonian Center for Astrophysics, USA), Eiji Akiyama (Hokkaido University, Japan), Motohide Tamura (The University of Tokyo; Astrobiology Center, NINS, Japan), and John Wisniewski (U. of Oklahoma, USA)

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the atacama large millimeter/submillimeter array

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News - Exciting Structures Discovered in a Young Protoplanetary Disk Lend Strong Support to Planet Formation in the Disk - ALMA

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An international research team, led by Dr. Ruobing Dong at University of Arizona in USA and in Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan, has discovered the tale-telling signs of planets in the young, likely planet-forming disk around the star MWC 758.

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'Red Nuggets' are Galactic Gold for Astronomers

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Observatorio NOEMA - Nube Molecular en la Galaxia Kiso 5639

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Observatorio NOEMA - Nube Molecular en la Galaxia Kiso 5639

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The numerous fuzzy blobs and glowing shapes scattered across this image make up a galaxy cluster named RXC J0949.8+1707.

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Anomalías  Ionosféricas Sismogénicas asociadas con el fuerte terremoto (M8.5) ocurrido el 11 de Abril del 2012 en Indonesia

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Anomalías  Ionosféricas Sismogénicas asociadas con el fuerte terremoto (M8.5) ocurrido el 11 de Abril del 2012 en Indonesia

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Seismogenic ionospheric anomalies associated with the strong Indonesian earthquake occurred on 11 April 2012 (M = 8.5)

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Ionospheric perturbations in possible association with a major earthquake (EQ) (M = 8.5) which occurred in India-Oceania region are investigated by mo...

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Estadística de Precursores Ionosféricos-Sísmicos de terremotos de M7.0+ en el cinturón sísmico Circum-Pacífico medidas usando GPS TEC

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Estadística de Precursores Ionosféricos-Sísmicos de terremotos de M7.0+ en el cinturón sísmico Circum-Pacífico medidas usando GPS TEC

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Statistical seismo-ionospheric precursors of M7.0+ earthquakes in Circum-Pacific seismic belt by GPS TEC measurements

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The Circum-Pacific seismic belt is the region heavily affected by earthquakes in the world. The relationship between earthquake (e.g., the geographic ...

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Statistical seismo-ionospheric precursors of M7.0+ earthquakes in Circum-Pacific seismic belt by GPS TEC measurements

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The Circum-Pacific seismic belt is the region heavily affected by earthquakes in the world. The relationship between earthquake (e.g., the geographic ...

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Volcán, Magnetismo de Manchas Solares, Hoyo Coronal

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Volcán, Magnetismo de Manchas Solares, Hoyo Coronal

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Volcano, Sunspot Magnetism, Coronal Hole | S0 News Jun.23.2018

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Earthquake, Solar Watch, Agenda 21 | S0 News Jun.22.2018

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Earthquake, Solar Watch, Agenda 21 | S0 News Jun.22.2018

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Earthquake, Solar Watch, Agenda 21 | S0 News Jun.22.2018

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Anomalía Eléctrica en EU , Oxígeno Cósmico

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Anomalía Eléctrica en EU , Oxígeno Cósmico

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Central US Lightning Anomaly, Cosmic Oxygen | S0 News Jun.21.2018

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El Cecimiento de una Gran Mancha Solar, Tormentas, Terremotos

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El Cecimiento de una Gran Mancha Solar, Tormentas, Terremotos

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Large Sunspot Growing, Storms, Quakes | S0 News Jun.20.2018

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Meteor, Electroquake, Space Weather | S0 News Jun.24.2018

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Estrella triturada por un rara variedad de Agujero Negro

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Estrella triturada por un rara variedad de Agujero Negro

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One of the few methods scientists can use to try to find an IMBH is to wait for a star to pass close to it and become disrupted. This event causes the black hole to emit a flare that can be observed by telescopes like Chandra.

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global temperature and precipitation maps

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Global Temperature and Precipitation Maps | Temperature, Precipitation, and Drought | National Centers for Environmental Information (NCEI)

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Monthly, Seasonal, and Annual Global Temperature, Precipitation, and Extremes Maps

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Cazando moléculas para encontrar nuevos planetas

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Cazando moléculas para encontrar nuevos planetas

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The planet becomes visible when looking for H2O or CO molecules. However, as there is no CH4 nor NH3 in its atmosphere, it remains invisble when looking for these molecules, just as its host star which contains none of those four elements. La planète devient visible lorsqu'on cherche de l'eau (H2O) ou du CO.

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Terremotos Lentos sobre la Falla  de San Andrés incrementan el riesgo de grandes terremotos, afirman los geofísicos del ASU.

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Terremotos Lentos sobre la Falla  de San Andrés incrementan el riesgo de grandes terremotos, afirman los geofísicos del ASU.

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'Juneteenth emerged in part to reclaim the central importance of black history - to put African-Americans back into the story of American history,' says ASU professor

Juneteenth, a portmanteau of the words "June" and "nineteenth," was born out of what was once referred to as the "peculiar institution" A euphemism for slavery used by white southerners in the 19th century. of the United States.

It references the day 153 years ago this year when a quarter of a million people - still held captive in the years after the Emancipation Proclamation Issued on Jan. 1, 1863, the Emancipation Proclamation declared free all people living in slavery in Confederate States that were still in rebellion. - walked away from the fields in which they were forced to toil; out of the houses in which they served under duress; and onto the roads they constructed to begin a new but uncertain future as free men, women and children.

In colloquial expression it has been called America's "second Independence Day" after the Continental Congress approved the final text America's independence was formally declared two days earlier on July 2, 1776. of the Declaration of Independence from British rule on July 4, 1776. But for many, particularly those whose ancestry and lineage have been all but scrubbed from the annals of American history due to 250 years of that peculiar institution, Juneteenth, or Freedom Day, has come to represent a true day of independence from slaveholding rule.

"Juneteenth celebrations were as much about the unfinished work of freedom as about the accomplished fact of slavery's end," Schermerhorn said. "Freedom was already and not yet complete since economic and civil rights were slow to follow. Even the soldiers that proclaimed black Texans free of slavery encouraged them to keep their shoulders to the plow, stay in their places and to accept peace over justice."

Schermerhorn recently shared more about the history and significance of Juneteenth in this Q&A with ASU Now:

Question: What is Juneteenth, and what is the tradition behind the observance of the day?

Answer: Juneteenth began in 1865 in Texas when some 250,000 formerly enslaved people were officially freed - two and a half years after President Abraham Lincoln issued the Emancipation Proclamation. On June 19, 1865, Union Gen. Gordon Granger issued General Order No. 3, which read: "The people of Texas are informed that, in accordance with a proclamation from the Executive of the United States, all slaves are free." The order went on to assert "an absolute equality of personal rights and rights of property between former masters and slaves." Juneteenth, argues one historian Robert C. Conner in his 2013 book "General Gordon Granger: The Savior of Chickamauga and the Man Behind Juneteenth." , "was a new word signifying a new world."

African-Americans in Texas turned the day into a celebration of freedom and an occasion to push for equal rights and opportunities. At first, it was specific to Texas but moved with migrating black Texans all over the United States. Towns like Covert, Michigan, and Tucson, Arizona, were holding Juneteenth celebrations by the early 20th century. Since African-Americans migrating out of Texas tended to go west, the holiday migrated west with them, though by the late 20th century it was popular all over the U.S.
Q: Why was the Emancipation Proclamation not enforced in Texas?
A: The Emancipation Proclamation was a war measure authorizing the president as commander-in-chief of the armed forces to liberate enslaved people in states and parts of states in active rebellion against the U.S. on Jan. 1, 1863. It signaled that the Union war effort was now a war against slavery, but it was not enforceable in places outside Union control. Only when Texas as a state of the Confederacy fell to Union forces did emancipation arrive in law, despite the fact that many black Texans had already freed themselves as a practical matter. Gen. Granger arrived in June 1865 to reassert federal - not Confederate - supremacy and issued the emancipation order. Many, if not most white Texans did not accept the freedom verdict of the Civil War, and Texas did not ratify the 13th Amendment abolishing slavery until 1870, some five years after Congress passed it. Reconstruction-era Texas also saw some of the worst racist violence and murders of African-American people by white militants.
Q: What were some of the immediate challenges for the belatedly freed men and women of Texas after they received the news of their emancipation?
A: Freedom came with no back wages, no land transfer and no other compensation to those who were formerly enslaved. They received nothing but freedom and had to return to work under many circumstances for former owners who still owned land and other means of production. Many formerly enslaved people emerged in freedom on a war-torn landscape of sickness and scarcity. Some who had toiled all their lives were ill and unable to toil on. Others were orphans, injured or dislocated. The Civil War devastated large swaths of the American South, and economic recovery was haltingly slow.

In Texas as in many other areas, former enslavers took a dim view of people of African descent, offering labor contracts that looked a lot like slavery. Those gave way to sharecropping arrangements that put the croppers or tenants in perpetual debt. There were urban black populations who became middle class, voted and held public office. But despite the heroic struggles of civil rights leaders, African-American political participation and power was fleeting. The height of black political participation was in the years between when Congress remilitarized the South in 1867 and the panic of 1873, which sapped the political will of federal authorities to combat a militant white supremacist insurgency that took the form of the Ku Klux Klan and other Democratic Party political organizations.
Q: When and how was the first Juneteenth celebrated?
A: It was celebrated first in Austin in 1867, and by 1872 it was a celebration that drew crowds of thousands in parts of Texas. In subsequent years, some localities let prisoners out of jails for the day to join the celebration. In Galveston and elsewhere, women took the lead in celebrating Juneteenth and making it the pretext for political discussions. In 1919, when the National Association for the Advancement of Colored People (NAACP) opened a branch in Galveston, women activists used Juneteenth as a date to meet at churches and urge more resources for education for African-American children. By then Juneteenth was so important that even white employers gave black workers the day off.

It was celebrated with barbecues, parades, floats and speeches, many of which were organized by the Women's Nineteenth of June Committee in Galveston. It was therefore a day of protest and of celebration as an occasion to mark freedom that was only partly accomplished.

As Texas historian Elizabeth Hayes Turner argues, "No other public event instilled African-Americans with such awareness and historic pride, and perhaps no other event so publicly managed to voice the desire for sexual equality that black women had been quietly demonstrating in their churches, schools and clubs."

Q: It feels like we are at a point in time culturally where Americans are taking a deeper look at history and some of the narratives that have been left out of history books. Where does Juneteenth fall in with those "lost" narratives?

A: Juneteenth as an African-American celebration of emancipation rose in the late 20th century as a way of reviving earlier Freedom Day celebrations and, more generally, as a way of raising awareness of African-Americans' struggles against slavery and the racist violence of Jim Crow. It became the pretext for the Poor People's March on Washington, D.C., in 1968. Until the 1960s - and in many history books much later - black Americans were marginalized. Historians routinely ignored or downplayed slavery, Jim Crow violence and the racist legacies of both. Instead, a grand patriotic narrative held sway and American history was a triumphal story of white generals, inventors and leaders. We see a version of this process in debates and conflicts over Confederate monuments. Monuments to Confederate leaders and generals were put up as assertions of white supremacy cloaked in a language of local struggles against a distant tyrannical government - the government of Abraham Lincoln Historians, including Schermerhorn, say had the Confederacy won the war, millions of African Americans would have remained enslaved. . That and other such stories distorted or ignored troubled parts of American history.

The same is true of Native Americans, women and many immigrant groups. Juneteenth emerged in part to reclaim the central importance of black history - to put African-Americans back into the story of American history. It also revived a black holiday of remembrance. In the post-Civil War nation, Freedom Day celebrations varied from state to state among African-descended Americans who had been enslaved or were members of formerly enslaved families. African-Americans in parts of Virginia, for instance, celebrated Surrender Day on April 9, the day when the Confederate Army of Northern Virginia under Robert E. Lee surrendered. Whenever it was celebrated, the day usually coincided with an event signaling black freedom. But such celebrations fell off in the early 20th century, and they were revived generations later. Juneteenth became an official holiday in Texas in 1980, and proclamations in other states and locales have broadened it to a holiday commemorating emancipation and promoting respect and dignity of all peoples in freedom struggles.
Top Photo: "Emancipation" by Thomas Nast. Image courtesy of the Library of Congress

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'Slow earthquakes' on San Andreas Fault increase risk of large quakes, say ASU geophysicists

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Geologists have long thought that the central section of California's famed San Andreas Fault has a steady creeping movement that provides a safe release of energy. The thinking goes that it reduces the chance of a big quake that ruptures the entire fault.

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Tendencia al Calentamiento en la estación de frío en el delta del río Yangtze  y su correlación con el Anticiclón Siberiano.

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Tendencia al Calentamiento en la estación de frío en el delta del río Yangtze  y su correlación con el Anticiclón Siberiano.

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USGS: Volcano Hazards Program HVO Kilauea

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USGS: Volcano Hazards Program - Hawaiian Volcano Observatory USGS Volcano Science Center Kilauea monitoring: Tilt and GPS Deformation Data.

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Sondeo de la Línea de Absorción del 21-Sponge Hi: La Temperatura Galáctica Hi.

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Sondeo de la Línea de Absorción del 21-Sponge Hi: La Temperatura Galáctica Hi.

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Turbulencia Cinética en Plasmas Astrofísicos: ¿Ondas y/o Estructuras?

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Turbulencia Cinética en Plasmas Astrofísicos: ¿Ondas y/o Estructuras?

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Earthquake Risk, Flurry of Sunspots | S0 News Jun.19.2018

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Impacto del Viento Solar, Explosión Volcánica, Fuertes Tormentas

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Impacto del Viento Solar, Explosión Volcánica, Fuertes Tormentas

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Solar Wind Impact, Volcano Bursts, Major Storms | S0 News Jun.18.2018

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Journal of Advances in Modeling Earth Systems (JAMES)

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La Firma del Viento Solar a través de la atmósfera en altas latitudes

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La Firma del Viento Solar a través de la atmósfera en altas latitudes

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Journal of Advances in Modeling Earth Systems (JAMES)

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El Polvo modifica la conductividad del Plasma en la mesosfera terrestre

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El Polvo modifica la conductividad del Plasma en la mesosfera terrestre

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Boats and boating--Equipment and supplies

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Dust modification of the plasma conductivity in the Earth's mesosphere

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Relative transverse drift (with respect to the ambient magnetic field) between the weakly magnetized electrons and the unmagnetized ions at the lower ...

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SVS: Visualizations of Hunga Tonga Hunga Ha'apai and the Martian Landscape

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In early 2015, a volcanic eruption in the Kingdom of Tonga created a new island informally known as Hunga Tonga Hunga Ha'apai (HTHH). The subsequent evolution of the new island was previously described in "The Birth of a New Island" available here .

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Large parts of the massive East Antarctic Ice Sheet did not retreat significantly during a time when atmospheric carbon dioxide concentrations were similar to today's levels, according to a team of researchers funded by the National Science Foundation (NSF). The finding could have significant implications for global sea level rise.

The East Antarctic Ice Sheet is one of three major ice sheets closely watched by scientists as global temperatures and carbon dioxide levels increase, glaciers melt and sea levels rise. Of the three, the East Antarctic Ice Sheet is the largest potential contributor to sea level rise.

To gauge the ice sheet's stability, researchers took ultra-sensitive analytical measurements of chemical signatures in sediment samples taken from the ice sheet's sea bed. They concluded that some ice on the southernmost part of the continent could be stable in a warming climate, as was the case during the Pliocene Epoch.

But they also caution that ongoing, rising carbon emissions mean that carbon dioxide levels will soon surpass the benchmark set during the Pliocene -- approximately 5.3 to 2.6 million years ago -- the last time Earth experienced carbon dioxide levels higher than 400 parts per million.

The findings were published today in the journal Nature.

The researchers relied on samples taken as part of the international ANtarctic geological DRILLing (ANDRILL) project. NSF funded the U.S. participation in ANDRILL.

Examining sediment samples delivered from land-based sections of the ice sheet, the researchers found those areas that drain into Antarctica's Ross Sea have been stable for the past 8 million years.

The geological history of the massive ice sheet -- frozen both above and, in many places, below the ocean's surface -- has been difficult to pinpoint. The absence of data about the East Antarctic Ice Sheet's response to warming in the past have hindered efforts to predict its role in future sea level rise.

This study focused on the portion of the ice sheet that sits above the ocean. It holds enough water to cause as much as 34 meters of sea level rise if the ice sheet were to melt completely.

Another component of the East Antarctic Ice Sheet, marine-based ice, sits below sea level and is thus directly affected by the ocean.

"Based on this evidence from the Pliocene, today's current carbon dioxide levels are not enough to destabilize the land-based ice on the Antarctic continent," said Jeremy Shakun, an assistant professor of Earth and Environmental Science at Boston College and a lead author on the paper.

"This does not mean that at current atmospheric carbon dioxide levels Antarctica won't contribute to sea level rise. Marine-based ice is already starting to add to sea level rise and alone could contribute as much as 20 meters. We're saying that the terrestrial segment of the ice sheet is more resilient at current carbon-dioxide levels."

Shakun's co-authors on the paper include Carling C. Hay, also of Boston College; researchers Lee B. Corbett, Paul R. Bierman, Kristen Underwood and Donna M. Rizzo of the University of Vermont; Susan R. Zimmerman of the Lawrence Livermore National Laboratory; Marc W. Caffee of Purdue University; and Tim Naish and Nicholas R. Golledge of Victoria University of Wellington, New Zealand.

Estimates on global sea level rise due to melt from the East Antarctic Ice Sheet during the Pliocene vary from 5 meters to more than 40 meters higher than today. The upper end of this range would imply that most of the ice on the planet melted, enough to raise sea levels by 63 meters.

If the land-based East Antarctic Ice Sheet was stable during the Pliocene, as Shakun and colleagues suggest, the Pliocene total could have been at most 30 meters.

The researchers analyzed sediment contained in drill cores taken from the sea floor. These cores contain geological records, but also chemical signatures -- in particular, the rare isotopes beryllium-10 and aluminum-26, which were extracted at the NSF-funded Community Cosmogenic Facility at the University of Vermont and measured using particle accelerators at Purdue University and Lawrence Livermore National Laboratory.

Both isotopes are found in rock surfaces that have been exposed to cosmic radiation bombarding the Earth from outer space. Researchers usually examine rock samples from hillsides, mountain tops and rivers to determine where and when ice retreated during prior geological eras.

Shakun and some of the co-authors of the latest report used a different approach two years ago to offer one of the most comprehensive climatological accounts ever compiled of the Greenland Ice Sheet, dating back 7.5 million years.

In the Greenland study, levels of beryllium-10 found in sandy deposits brought out to sea in icebergs suggested the ice sheet has been a "persistent and dynamic" presence that melted and re-formed periodically in response to temperature fluctuations. The findings helped confirm that the Greenland Ice Sheet is a sensitive responder to global climate change.

Earlier studies of the East Antarctic Ice Sheet indicated that some marine-based portions of the ice sheet and its neighboring West Antarctic Ice Sheet retreated during the Pliocene. But it was unclear whether terrestrial ice also retreated.

Their analysis found "extremely low" concentrations of beryllium and aluminum isotopes in quartz sand in the marine sediment samples taken in the region, which leads to the conclusion that the ice sheet has been stable for millions of years.

While the sediment was the product of erosion from the continent, the low levels of tell-tale chemical signatures reveal that the sediment experienced only minimal exposure to cosmic radiation, leading the team to conclude East Antarctica must have remained covered in ice.

According to the paper's authors, "the findings indicate that atmospheric warming during the past eight million years was insufficient to cause widespread and/or long-lasting meltback of the EAIS margin onto land."

The findings not only clarify the past impact of rising temperatures on East Antarctic ice, said Shakun, but confirm the accuracy of models scientists are using to assess past and future consequences of a warming planet.

-NSF-

Media Contacts
Peter West, NSF, (703) 292-7530, email: pwest@nsf.gov

Principal Investigators
Jeremy D. Shakun, Boston College, (617) 552-1625, email: jeremy.shakun@bc.edu

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2018, its budget is $7.8 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives more than 50,000 competitive proposals for funding and makes about 12,000 new funding awards.
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Land-based portion of massive East Antarctic Ice Sheet retreated little during past 8 million years | NSF - National Science Foundation

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Large parts of the massive East Antarctic Ice Sheet did not retreat significantly during a time when atmospheric carbon dioxide concentrations were similar to today's levels, according to a team of researchers funded by the National Science Foundation (NSF). The finding could have significant implications for global sea level rise.

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Weather Outlook, Antarctic Imagination | S0 News Jun.16.2018

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El Sol afecta las atmósferacompleta, Electrosismos

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El Sol afecta las atmósferacompleta, Electrosismos

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Sun Affects Whole Atmosphere, Electroquakes | S0 News Jun.17.2018

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Plot of locations (from log at https://t.co/Fl9aKcLmem) of #AA1897 flight, which encountered hail and severe turbulence https://t.co/OAHI5qSmD6 last night, on radar imagery and a 3-D view of the hail core

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Plot of locations (from log at https://t.co/Fl9aKcLmem) of #AA1897 flight, which encountered hail and severe turbulence https://t.co/OAHI5qSmD6 last night, on radar imagery and a 3-D view of the hail core https://t.co/3E3Dg9Z8Wv

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Plot of locations (from log at https://t.co/Fl9aKcLmem) of #AA1897 flight, which encountered hail and severe turbulence https://t.co/OAHI5qSmD6 last night, on radar imagery and a 3-D view of the hail core https://t.co/3E3Dg9Z8Wv

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Plot of locations (from log at https://t.co/Fl9aKcLmem) of #AA1897 flight, which encountered hail and severe turbulence https://t.co/OAHI5qSmD6 last night, on radar imagery and a 3-D view of the hail core https://t.co/3E3Dg9Z8Wv

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Plot of locations (from log at https://t.co/Fl9aKcLmem) of #AA1897 flight, which encountered hail and severe turbulence https://t.co/OAHI5qSmD6 last night, on radar imagery and a 3-D view of the hail core

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Hubble Images a Galaxy with Threads of Blue

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A ripple of bright blue gas threads through this galaxy like a misshapen lake system.

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SVS: Parker Solar Probe and Solar Orbiter Trajectories

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The next missions scheduled for detailed studies of the Sun and solar atmosphere are Parker Solar Probe and Solar Orbiter . Parker Solar Probe moves in a highly-elliptical orbit, using gravity-assists from Venus to move the orbit perihelion closer to the Sun with each pass.

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Solar Storm Psyche | From Stress to Suicide

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Space Weather Health Alerts | What To Do

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What am I looking at?

Meteor showers on Earth are caused by streams of meteoroids hitting our atmosphere. These meteoroids are sand- and pebble-sized bits of rock that were once released from their parent comet. Some comets are no longer active and are now called asteroids.

This visualization shows these meteoroid streams orbiting the Sun, some stretching to the outer regions of the solar system. Select the meteor shower in the menu to see the corresponding meteoroid stream in space. Their meteoroid orbits are based on those measured by NASA's CAMS video camera surveillance network, and were calculated by meteor astronomer Peter Jenniskens of the SETI Institute and NASA Ames Research Center.

This visualization is developed and hosted by Ian Webster.

How can I see a meteor shower?

Meteor showers are best seen on certain dark and clear nights. To see how many meteors per hour are visible from your location, go to this website and select the date, the shower, and your location.

Where should I go next?

If you like these sorts of interactive visualizations, take a look at Ian Webster's other tools, including Pluto, ancient Earth, or asteroids!

Can I use this on my site?

Sure! Use the following code to load the interactive visualization in an iframe. You must know the IAU number of your meteor shower, which you can look up here.

<iframe src="https://www.meteorshowers.org/view/iau-7" width="500" height="500" frameBorder="0"></iframe>

Please remember to attribute this site!

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3D visualization of NASA meteor shower data. Scientifically accurate and fully interactive.

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Low dose or low dose rate ionizing radiation-induced health effect in the human

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The extensive literature review on human epidemiological studies suggests that low dose ionizing radiation (LDIR) (≤100 mSv) or low dose rate ionizing...

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AAAS - The World's Largest General Scientific Society

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Organisms from deep sea hydrothermal vents are among the ocean dwellers with patented genetic material. | NOAA Ocean Exploration & Research

One corporation has registered nearly half of all patents on marine genetic sequences and virtually all marine genetic resource patents are registered to entities from only ten countries, according to a study published in the June 6 issue of Science Advances.

The analysis also revealed that a single corporation - BASF, the world's largest chemical producer, headquartered in Germany - registered 47% of all patented marine sequences. Furthermore, entities located or headquartered in ten countries registered 98% of all patented sequences, suggesting that 165 countries are underrepresented, said the study authors.

The findings highlight the need for inclusive global participation in the United Nations Convention on the Law of the Sea treaty negotiations starting in September 2018 that will address the use of marine biodiversity in international waters.

According to Robert Blasiak, an author of the study from Stockholm University, the entities that own the majority of patents related to marine biodiversity "could play a very important and valuable role in supporting efforts to ensure that areas beyond national jurisdiction can be accessed by all and benefit all."

Many marine organisms have evolved unique adaptations to succeed in some of the ocean's most extreme conditions, such as extreme pressure, heat and cold. Their unique genes could be useful for a number of applications, ranging from pharmaceuticals to enzymes that can be used to synthesize biofuels. Companies, organizations and universities register patents that are associated with these marine genetic resources (MGRs) to have exclusive access to their potential economic benefits.

Blasiak and colleagues said little is known about MGR patents. Studies so far have only focused on countries where patents have been registered, rather than on the individual entities registering them.

"I was often surprised to hear people talking about countries owning patents, or about countries patenting MGRs. This always confused me because I always associated patents with commercial endeavors and companies - not countries. Yet, I couldn't find any research showing what companies were actually registering these patents." said Blasiak.

To shed light on who holds MGR patents and what types of marine species are being included in such claims, Blasiak and colleagues accessed 38 million records of patented genetic sequences and identified patents for 12,998 genetic sequences extracted from 862 marine species, including the sperm whale, manta ray and plankton.

"Everything [we found] was a surprise, to be honest," said Blasiak.

A wide range of species have been the focus of patents. The majority (about 73%) are associated with microbial species. Fish represent 16% of the registered patents and 11% of patented sequences are from species associated with deep sea hydrothermal vent systems.

The analysis also revealed that 221 companies had registered 84% of all patents. Public and private universities, on the other hand, only accounted for 12% of all patents.

Blasiak said the fact that specific companies and countries are patenting large amounts of MGRs is not a concern by itself, noting that "many of these actors are industry leaders and dedicate tremendous resources to research and development, paving the way for new innovations."

The concerning issue, Blasiak said, is that more entities - especially ones from the global south - are not involved in marine patenting. This creates an uneven playing field for developing countries who sign on to the UNCLOS treaty, and may continue to stall treaty negotiations until participating developed countries with more resources commit to supporting equitable development and transfer of marine technology. This support, Blasiak and colleagues said, will ensure that the process moves forward in an inclusive manner.

The countries and companies that own the majority of MGR patents have a unique opportunity to play an important role in the future of high seas biodiversity and its governance, said Blasiak. "So much remains to be discovered that will benefit human society ... [These countries and companies] can be leaders in promoting a more equitable roadmap for ensuring sustainable use of ocean resources."

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One Corporation Holds Most of Ocean's Genetic Patents

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Organisms from deep sea hydrothermal vents are among the ocean dwellers with patented genetic material. | NOAA Ocean Exploration & Research One corporation has registered nearly half of all patents on marine genetic sequences and virtually all marine genetic resource patents are registered to entities from only ten countries, according to a study published in the June 6 issue of Science Advances.

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TLE over Austria and Hungary 8.-9.6.2018

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This turbulent celestial palette of purple and yellow shows a bubble of gas named NGC 3199, blown by a star known as WR18 (Wolf-Rayet 18).Wolf-Rayet stars are massive, powerful, and energetic stars that are just about reaching the end of their lives. They flood their surroundings with thi...

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Press Release - Diamond Dust Shimmering around Distant Stars

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In astronomy, nanodiamonds are special in that their structure produces what is known as a "dipole moment" - an arrangement of atoms that allows them to emit electromagnetic radiation when they spin.

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Eufemia Garcia watched in horror as Guatemala's Fuego volcano sent scalding ash and gas surging over her home a week ago, burying her children and grandson among 50 of her extended family. She has been searching for their remains ever since.

At least 110 people died after Fuego erupted last Sunday, pushing fast-moving currents of dust, lava and gas down the volcano's slopes in its greatest eruption in four decades, and close to 200 more are believed buried beneath the waste.

Among them, Garcia believes, her nine siblings and their families as well as her mother, her own grown-up children and a grandson, making her family one of the hardest hit in a disaster that officials admit was made worse by delays in official warnings.

The hamlet of San Miguel Los Lotes on the lush southern flank of the volcano was almost completely swallowed by several metres of ash, and formal search efforts have been suspended until the still-erupting volcano stabilises.

Defying the suspension order, Garcia, 48, leaves the shelter she now sleeps in each morning, grabs a pickaxe or a shovel and heads into the danger zone, where groups of volunteers and other families dig down through ash hardened by rain and sun to try and reach their homes below.

Another desperate survivor, Bryan Rivera, is searching for 13 missing relatives. All he has found so far in the dust and desolation is a guitar his 12-year-old sister had loved to play.

"I'm not going to give up until I have a part of my family and am able to give them a Christian burial," Garcia said.

A fruit seller who lived for more than three decades with her extended family in Los Lotes, Garcia said she was out purchasing eggs when she saw the volcanic flow racing toward her village.

She sprinted back to her family's homes, where uncles and a brother, children and cousins were preparing for a lunch to celebrate a sister visiting from a nearby town.

She shouted at them to flee but few heeded the warnings. Her 75-year-old mother decided she could not outrun the danger. "Let God's will be done," she said.

Garcia ran to safety and looked back to see the burning flow rise to the roof of her house, submerging it completely with her son Jaime, 21, inside. She watched as the ash rushed toward her daughter Vilma Liliana, 23, who sprinted for safety barefoot but was unable to outpace its terrible path.

Her other daughter Sheiny Rosmery, 28, stayed at home, her son in her arms. The visiting sister and her husband have not been found.

With almost no family left, she does not know where she will live next, or what she will do to survive. But for now, she says, all that matters is the search.

She ticks off a list of her missing, including her three children, her mother, her grandson, brothers, sisters, nephews, children of nephews and brothers-in-law, generations of a relatives among the clutch of families that settled in Los Lotes in the 1970s.

The only survivors are Garcia and a brother who long ago moved away.
"I've looked here in the morgue and in another morgue, but there is no sign of them," she said, standing in front of a row of coffins at a makeshift mortuary.
"My family is buried. All 50 of them."
Topics

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Guatemala volcano: woman searches for 50 buried relatives

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Eufemia Garcia watched in horror as Guatemala's Fuego volcano sent scalding ash and gas surging over her home a week ago, burying her children and grandson among 50 of her extended family. She has been searching for their remains ever since.

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SVS: Visualizations of Hunga Tonga Hunga Ha'apai and the Martian Landscape

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In early 2015, a volcanic eruption in the Kingdom of Tonga created a new island informally known as Hunga Tonga Hunga Ha'apai (HTHH). The subsequent evolution of the new island was previously described in "The Birth of a New Island" available here .

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New GAIA data reveals mergers in Milky Way

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University of Groningen astronomers have discovered relics of merger events in the Milky Way halo. Five small groups of stars appear to represent mergers with smaller galaxies, while a big 'blob' comprising hundreds of stars appears to be the remnant of a large merger event.

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A new analysis of data from NASA's Dawn mission suggests that organic matter may exist in surprisingly high concentrations on the dwarf planet's surface.

PROVIDENCE, R.I. [Brown University] - Last year, scientists with NASA's Dawn mission announced the detection of organic material - carbon-based compounds that are necessary components for life - exposed in patches on the surface of the dwarf planet Ceres. Now, a new analysis of the Dawn data by Brown University researchers suggests those patches may contain a much higher abundance of organics than originally thought.

The findings, published recently in Geophysical Research Letters, raise intriguing questions about how those organics got to the surface of Ceres, and the methods used in the new study could also provide a template for interpreting data for future missions, the researchers say.

"What this paper shows is that you can get really different results depending upon the type of organic material you use to compare with and interpret the Ceres data," said Hannah Kaplan, a postdoctoral researcher at the Southwest Research Institute who led the research while completing her Ph.D. at Brown. "That's important not only for Ceres, but also for missions that will soon explore asteroids that may also contain organic material."

Organic molecules are the chemical building blocks for life. Their detection on Ceres doesn't mean life exists there or ever existed there; non-biological processes can give rise to organic molecules as well. But because life as we know it can't exist without organic material, scientists are interested in how it's distributed through the solar system. The presence of organic material on Ceres raises intriguing possibilities, particularly because the dwarf planet is also rich in water ice, and water is another necessary component for life.

The original discovery of organics on Ceres was made using the Visible and Infrared (VIR) Spectrometer on the Dawn spacecraft, which went into orbit around the dwarf planet in 2015. By analyzing the patterns in which sunlight interacts with the surface - looking carefully at which wavelengths are reflected and which are absorbed - scientists can get an idea of what compounds are present on Ceres. The VIR instrument picked up a signal consistent with organic molecules in the region of Ernutet Crater on Ceres' northern hemisphere.

To get an initial idea of how abundant those compounds might be, the original research team compared the VIR data from Ceres with laboratory reflectance spectra of organic material formed on Earth. Based on that standard, the researchers concluded that between six and 10 percent of the spectral signature they detected on Ceres could be explained by organic matter.

But for this new research, Kaplan and her colleagues wanted to re-examine those data using a different standard. Instead of relying on Earth rocks to interpret the data, the team turned to an extraterrestrial source: meteorites. Some meteorites - chunks of carbonaceous chondrite that have fallen to Earth after being ejected from primitive asteroids - have been shown to contain organic material that's slightly different from what's commonly found on our own planet. And Kaplan's work shows that the spectral reflectance of the extraterrestrial organics is distinct from that of terrestrial counterparts.

"What we find is that if we model the Ceres data using extraterrestrial organics, which may be a more appropriate analog than those found on Earth, then we need a lot more organic matter on Ceres to explain the strength of the spectral absorption that we see there," Kaplan said. "We estimate that as much as 40 to 50 percent of the spectral signal we see on Ceres is explained by organics. That's a huge difference compared to the six to 10 percent previously reported based on terrestrial organic compounds."

If the concentration of organics on Ceres is indeed that high, it raises a host of new questions about the source of that material. There are two competing possibilities for where Ceres' organics may have come from. They could have been produced internally on Ceres and then exposed on the surface, or they could have been delivered to the surface by an impact from an organic-rich comet or asteroid.

This new study suggests that if the organics were delivered, then the potential high concentrations of the organics would be more consistent with impact by a comet rather than an asteroid. Comets are known to have significantly higher internal abundances of organics compared with primitive asteroids, potentially similar to the 40 to 50 percent figure this study suggests for these locations on Ceres. However, the heat of an impact would likely destroy a substantial amount of a comet's organics, so whether or not such high abundances could even be explained by a cometary impact remains unclear, the researchers say.

The alternative explanation, that the organics formed directly on Ceres, raises questions too. The detection of organics has so far been limited to small patches on Ceres' northern hemisphere. Such high concentrations in such small areas require an explanation.

"If the organics are made on Ceres, then you likely still need a mechanism to concentrate it in these specific locations or at least to preserve it in these spots," said Ralph Milliken, an associate professor in Brown's Department of Earth, Environmental and Planetary Sciences and a study co-author. "It's not clear what that mechanism might be. Ceres is clearly a fascinating object, and understanding the story and origin of organics in these spots and elsewhere on Ceres will likely require future missions that can analyze or return samples."

For now the researchers hope this study will be helpful in informing upcoming sample return missions to near-Earth asteroids that are also thought to host water-bearing minerals and organic compounds. The Japanese spacecraft Hayabusa2 is expected to arrive at the asteroid Ryugu in several weeks, and NASA's OSIRIS-REx mission is due to reach the asteroid Bennu in August. Kaplan is currently a science team member with the OSIRIS-REx mission.

"I think the work that went into this study, which included new laboratory measurements of important components of primitive meteorites, can provide a framework of how to better interpret data of asteroids and make links between spacecraft observations and samples in our meteorite collection," Kaplan said. "As a new member to the OSIRIS-REx team, I'm particularly interested in how this might apply to our mission."

The research was funded by the NASA Astrobiology Institute and the NASA Solar System Exploration Research Virtual Institute at Brown.

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Organics on Ceres may be more abundant than originally thought

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A new analysis of data from NASA's Dawn mission suggests that organic matter may exist in surprisingly high concentrations on the dwarf planet's surface. PROVIDENCE, R.I. [Brown University] - Last year, scientists with NASA's Dawn mission announced the detection of organic material - carbon-based compounds that are necessary components for life - exposed in patches on the surface of the dwarf planet Ceres.

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Magnetic measurements made during low-altitude airplane flights conducted for the U.S. Geological Survey and the Oklahoma Geological Survey reveal possible deep faults that may contribute to increased seismic activity in response to wastewater injection in certain portions of Oklahoma.

The data and results from the August through October, 2017, deep-imaging magnetic survey were recently published in Geophysical Research Letters.

Oklahoma has been the site of thousands of earthquakes associated with wastewater injection activity, or induced seismicity, but few of the earthquake sequences have occurred on mapped faults, making seismic hazards difficult to estimate.

The USGS and the OGS used the newly acquired airborne magnetic data to image rocks where the earthquakes are occurring miles beneath the surface. The magnetic field maps reveal boundaries or contacts between different rock types, some of which are linear, similar to faults. A number of these types of contacts, (referred to as "lineaments" in the magnetic field map), are aligned with sequences of earthquakes. This suggests that some of them represent ancient faults that have been reactivated due to wastewater injection, which generates, or "induces" earthquakes.

"We are hoping the results will be used to guide more detailed studies at local scales to assess potential earthquake hazards," said USGS scientist Anji Shah, lead author for the study.

Additionally, the data show that there is a dominant "grain" direction to the magnetic contacts (like wood grain) in the deep rocks where the earthquakes are occurring. This "grain" was formed hundreds of millions of years ago and may be composed in part by faults that are oriented favorably to move in response to natural background stresses within the earth. This alignment of deep features may contribute to the high levels of seismicity occurring in response to wastewater injection.

"There is nothing like a new data set to excite geoscientists looking for answers to some of the mysteries of induced seismicity in Oklahoma," said Dr. Jeremy Boak, OGS Director. "We look forward to discussing these results among ourselves and with the interested technical community. We also hope to bring these data to bear on addressing the persistent seismic activity and sharing our interpretations with Oklahomans and other stakeholders regarding this challenging issue."

Survey areas included parts of Alfalfa, Beckham, Comanche, Greer, Harmon, Kiowa, Jackson, Lincoln, Logan, Major, Noble, Pawnee, Payne, Pottawatomie, Stephens, Tillman, Woods and Woodward counties.

Other relevant findings of the USGS/OGS study:

Many of the possible deep faults highlighted by the magnetic data are different from those on previous fault maps. This discrepancy is probably because the previous maps reflect relatively young faults in the shallow rocks, whereas the magnetic data image the deeper, older rocks. The differences in the fault directions between these rock types are probably due to the different histories of ancient tectonic and magmatic events that shaped the rocks.

USGS provides science for a changing world. Visit USGS.gov, and follow us on Twitter @USGS and our other social media channels.

Subscribe to our news releases via e-mail, RSS or Twitter.

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Oklahoma Study Reveals Possible, Previously Unknown Sources of Earthquakes

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The data and results from the August through October, 2017, deep-imaging magnetic survey were recently published in Geophysical Research Letters.Oklahoma has been the site of thousands of earthquakes associated with wastewater injection activity, or induced seismicity, but few of the earthquake sequences have occurred on mapped faults, making seismic hazards difficult to estimate.

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Rocks Under I-95 Present Odd, and Scary, Threat to Power Grid

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A solar storm is now viewed as enough of a risk in fact that grid operators across North America are working on plans to respond to just such a disturbance. And a draft of a soon-to-be-published U.S. Geological Survey report pinpoints the Eastern Seaboard as one of the areas most in danger.

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ALMA descubre 3 planetas infantes alrededor de una nueva estrella

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ALMA descubre 3 planetas infantes alrededor de una nueva estrella

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ALMA Discovers Trio of Infant Planets around Newborn Star - Novel technique to find youngest planets in our galaxy

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Two independent teams of astronomers have used ALMA to uncover convincing evidence that three young planets are in orbit around the infant star HD 163296. Using a novel planet-finding technique, the astronomers identified three disturbances in the gas-filled disc around the young star: the strongest evidence yet that newly formed planets are in orbit there.

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Cosmic Ray Psyche | More-Direct Effect/Mitigation Protocol

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Clima Espacial, Hawái, ¿Centauri habitable?

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Clima Espacial, Hawái, ¿Centauri habitable?

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Space Weather, Hawaii, Habitable Centauri? | S0 News Jun.9.2018

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Sol, Tormentas, Radiación, el Adueñándose del Océano

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Sol, Tormentas, Radiación, el Adueñándose del Océano

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Sun, Storms, Radiation, Owning the Ocean | S0 News Jun.10.2018

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Nueva Mancha Solar, Tormenta Severas, Polvo

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Nueva Mancha Solar, Tormenta Severas, Polvo

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New Sunspots, Severe Storms, Dust | S0 News Jun.11.2018

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Incremento en Rayos Cósmicos, Información de Volcanes, Próximas Grandes Noticias

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Incremento en Rayos Cósmicos, Información de Volcanes, Próximas Grandes Noticias

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Cosmic Rays Rising, Volcano Data, Big News Coming | S0 News Jun.12.2018

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Tormentas, Manchas Solares, Tornado Fractal

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Tormentas, Manchas Solares, Tornado Fractal

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Storms, Sunspots, Fractal Tornado | S0 News Jun.13.2018