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10,000 Galaxies

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HubbleSite - Out of the ordinary... out of this world

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Short and Simple

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NASA

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Our galaxy, the Milky Way, is typical: it has hundreds of billions of stars, enough gas and dust to make billions more stars, and about six times as much dark matter as all the stars and gas put together. And it's all held together by gravity.

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Hubble Space Telescope - Facts for Kids | Educational Videos by Mocomi

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Hubble Space Telescope

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ESA - Kids - Life in Space - The Hubble Space Telescope

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The Hubble Space Telescope (HST) is the most famous - and probably most successful - space observatory ever flown. The 11 tonne telescope was placed into a 570 km high orbit around Earth by the Space Shuttle in April 1990. Circling our planet every 96 minutes, the HST has so far travelled some 5 billion km.

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SO AMAZING! MUST WATCH

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Mind Blowing! ...Earth Compared To The Rest Of The Universe  - Amazing Graphic Presentation

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MPL3D Solar System - Location of the Sun in the Milky Way

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Up to date location of the Sun in the Milky Way, according to the latest scientifically accepted galactic structure.

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The Earth orbits the Sun in the Solar System, and the Solar System is embedded within a vast galaxy of stars. Just one in hundreds of billions of galaxies in the Universe. Ours is called the Milky Way because the disk of the galaxy runs across the sky as a band of glowing light, like spilled milk.

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Shapes and what are they made of?

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Educational Games, Worksheets, and More for Kids

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An Educational platform for parents and teachers of pre-k through 7th grade kids. Support your kids learning journey with games, worksheets and more that help children practice key skills. Download, print & watch your kids learn today!

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How many stars in the Milky Way? In the Universe?!

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How many stars in the Milky Way? In the Universe?!

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Mind blowing! Tell Ms. Hammerly about these numbers!

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In this short explainer video, Universe Today publisher Fraser Cain explains just how many stars there are. How many can you see with your eyes, with binoculars or a small telescope? How many stars in the Milky Way? How many in the entire Universe? Short answer... a lot.

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Astronomer's unit of measurement

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A light-year is how astronomers measure distance in space. It's defined by how far a beam of light travels in one year - a distance of six trillion miles. Think of it as the bigger, badder cousin of the inch, the mile, the kilometer, and the furlong. If you like to keep up with what's going on in astronomy, it's worth spending a little bit of time understanding what the deal is with this funny unit of measurement.

Have you ever been on your way to meet some friends and, while en route, called to tell them you're running late? If you're like me, you might tell them "I'm about ten minutes away". You're using how long it will take you to get there as a substitute for how far away you are. Astronomers do the same thing when figuring out the distance to a star or galaxy, but instead of relying on how fast they could drive or walk, they use a beam of light as their reference.

Why do things this way? First, light is convenient. Throughout the universe, all light travels at exactly the same speed: about 670 million miles per hour. We don't usually think about light traveling anywhere because when we flick on a light switch - there it is! We don't have to wait for the room to light up. It happens instantaneously. Except that it's not instantaneous, just insanely fast. In fact, let's pause for a second and reflect on how ludicrously quick the speed of light is.

Traveling at that speed, you would encircle the globe of Earth almost eight times in one second.

Impressive! Certainly faster than traveling by airplane. So if you were to travel off the Earth in a straight line at light speed, you'd get pretty far in the same amount of time, right? Actually, since space is so vast, you wouldn't have even made it to the moon. Travel to the moon takes about a second-and-a-half, at light speed. Travel to the sun at light speed takes about eight minutes. Can you even imagine? Traveling at a speed where you cross nearly 200,000 miles every second for eight full minutes would only get you to the center of our solar system.

The fact that light takes time to get anywhere has an interesting side effect. If light from the sun takes eight minutes to get to us, then we're actually seeing the sun as it was eight minutes ago. We're looking into the past!

While this sounds a little crazy, it's actually something with which you're already familiar. If you've ever seen fireworks, for example, you know that you see the explosion and then a few seconds later you hear it. If you close your eyes during the fireworks show, you'd only have your ears to know when things were happening. Since it takes some time for the sound to get to you, you'd always be hearing things a few seconds after they happened. The same happens with light: we only see something once the light from that event actually gets to our eyes. When we're looking across a room, the time delay is only a few billionths of a second. But when we start looking across large enough distances, the light becomes noticeably delayed like the sounds are from exploding fireworks.

The main reason for using light years, however, is because the distances we deal with in space are immense. If we stick to miles or kilometers we quickly run into unwieldy numbers just measuring the distance to the nearest star: a dim red dwarf called Proxima Centauri that sits a mere 24,000,000,000,000 miles away! Using a longer yard stick, so to speak, helps keep the numbers at least manageable. To an astronomer, the distance to Proxima Centauri is only four light years. Put another way, it takes the light from our stellar next door neighbor four years to get to Earth.

The Milky Way galaxy in which our sun and all the stars we see at night reside spans 100,000 light-years from one end to the other. Putting that into perspective, the duration of recorded human history is roughly 5,000 years. So light from a star at one end of our galaxy takes 20 times longer than all of recorded history to get to the other end.

Moving beyond our galaxy, it's just over two million light years to our nearest galactic neighbor, the Andromeda galaxy. The light we currently see from that galaxy left there about the same time the ancestors of modern humans were first discovering stone tools.

Our last stop takes us to the edge of the visible universe. It's also here where the trickiness of measuring distance in an ever-expanding universe becomes apparent. The light we see coming from the farthest depths of the universe has been traveling across the cosmos for almost three times longer than our planet has existed: nearly 14 billion years! But there's a catch: we cannot say that the edge of the visible universe is 14 billion light-years away.

Why? Because the universe has grown larger in that time! A galaxy whose light took 14 billion years to reach our little planet has, in the intervening aeons, moved even further away. The current physical distance to that remote beacon, if we stopped the universe from expanding and stretched out a really long tape measure, is just over 46 billion light years! Even in light years, measuring distances across the universe becomes unwieldy. But measuring in something familiar, like miles, is truly humbling. From here to the edge of our vision spans a distance of approximately 276,000,000,000,000,000,000,000 miles.

And it's getting bigger every day.

Bottom line: How far is a light-year? It's the distance a beam of light travels in one year - a distance of six trillion miles.

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distance to sun and moon in light-minutes

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A light-year is how astronomers measure distance in space. It's defined by how far a beam of light travels in one year - a distance of six trillion miles. Think of it as the bigger, badder cousin of the inch, the mile, the kilometer, and the furlong.

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Although a couple of dozen minor galaxies lie closer to our Milky Way, the Andromeda galaxy is the closest major galaxy to ours. Excluding the Large and Small Magellanic Clouds, which can't be seen from northerly latitudes, the Andromeda galaxy - also known as M31 - is the brightest galaxy in all the heavens. It's the most distant thing you can see with your unaided eye, at 2.3 million light-years. To the eye, it appears as a smudge of light larger than a full moon. Follow the links below to learn more about the Andromeda galaxy.
When to look for the Andromeda Galaxy Find the Andromeda galaxy using the Great Square of Pegasus Find the Andromeda galaxy using the constellation Cassiopeia History of our knowledge of the Andromeda galaxy Andromeda and Milky Way in context
When to look for the Andromeda Galaxy. From mid-northern latitudes, you can see M31 - also called the Andromeda galaxy - for at least part of every night, all year long. But most people see the galaxy first in northern autumn, when it's high enough in the sky to be seen from nightfall till daybreak.

In late September and early October, the Andromeda galaxy shines in your eastern sky at nightfall, swings high overhead around midnight (1 a.m. daylight saving time) and stands rather high in the west at the onset of morning dawn. Winter evenings are also good for viewing the Andromeda galaxy.

If you are far from city lights, and it's a moonless night - and you're looking on an autumn or winter evening - it's possible you'll simply notice the galaxy in your night sky. It's looks like a hazy patch in the sky, as wide across as a full moon.

But if you look, and don't see the galaxy - yet you know you're looking at a time when it's above the horizon - you can star-hop to find the galaxy in one of two ways. First, you can use the Great Square of Pegasus. Second, you can use the constellation Cassiopeia.

Find the Andromeda galaxy using the Great Square of Pegasus. You'll be hopping to the Andromeda galaxy from the Great Square of Pegasus. In autumn, the Great Square of Pegasus looks like a great big baseball diamond in the eastern sky. Envision the bottom star of the Square's four stars as home plate, then draw an imaginary line from the "first base" star though the "third base" star to locate two streamers of stars flying away from the Great Square. These stars belong to the constellation Andromeda the Princess.

On each streamer, go two stars north (left) of the third base star, locating the stars Mirach and Mu Andromedae. Draw a line from Mirach through Mu Andromedae, going twice the Mirach/Mu Andromedae distance. You've just landed on the Andromeda galaxy, which looks like a smudge of light to the unaided eye.

If you can't see the Andromeda galaxy with the eye alone, by all means use binoculars.

Find the Andromeda galaxy using the constellation Cassiopeia. The constellation Cassiopeia the Queen is one of the easiest constellations to recognize. It is shaped like the letter M or W. Look generally northward on the sky's dome to find this constellation. If you can recognize the north star, Polaris - and if you know how to find the Big Dipper - be aware that the Big Dipper and Cassiopeia move around Polaris like the hands of a clock, always opposite each other.

To find the Andromeda galaxy via Cassiopeia, look for the star Schedar. In the illustration above, see how the star Schedar points to the galaxy?

Many people use the Cassiopeia to find the Andromeda galaxy, because Cassiopeia itself is so easy to spot.

History of our knowledge of the Andromeda galaxy. At one time, the Andromeda galaxy was called the Great Andromeda Nebula. Astronomers thought this patch of light was composed of glowing gases, or was perhaps a solar system in the process of formation.

It wasn't until the 20th century that astronomers were able to resolve the Andromeda spiral nebula into individual stars. This discovery lead to a controversy about whether the Andromeda spiral nebula and other spiral nebulae lie within or outside the Milky Way.

In the 1920s Edwin Hubble finally put the matter to rest, when he used Cepheid variable stars within the Andromeda galaxy to determine that it is indeed an island universe residing beyond the bounds of our Milky Way galaxy.

Andromeda and Milky Way in context. The Andromeda galaxy and our Milky Way galaxy reign as the two most massive and dominant galaxies within the Local Group of Galaxies. The Andromeda Galaxy is the largest galaxy of the Local Group, which, in addition to the Milky Way, also contains the Triangulum Galaxy, and about 30 other smaller galaxies.

Both the Milky Way and the Andromeda galaxies lay claim to about a dozen satellite galaxies. Both are some 100,000 light-years across, containing enough mass to make billions of stars.

Astronomers have discovered that our Local Group is on the outskirts of a giant cluster of several thousand galaxies - which astronomers call the Virgo Cluster.

We also know of an irregular supercluster of galaxies, which contains the Virgo Cluster, which in turn contains our Local Group, which in turn contains our Milky Way galaxy and the nearby and Andromeda galaxy. At least 100 galaxy groups and clusters are located within this Virgo Supercluster. Its diameter is thought to be about 110 million light-years.

The Virgo Supercluster is thought to be one of millions of superclusters in the observable universe.

Bottom line: At 2.3 million light-years, the Great Andromeda galaxy (Messier 31) rates as one of the most distant objects you can see with the unaided eye.

The Andromeda galaxy (M31) is at RA: 0h 42.7m; Dec: 41 o 16′ north
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Andromeda galaxy next door to Milky Way | EarthSky.org

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Although a couple of dozen minor galaxies lie closer to our Milky Way, the Andromeda galaxy is the closest major galaxy to ours. Excluding the Large and Small Magellanic Clouds, which can't be seen from northerly latitudes, the Andromeda galaxy - also known as M31 - is the brightest galaxy in all the heavens.

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Are they from other galaxies or our own?

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by Jonathan O'Callaghan, 27 December 2013

Where are the stars in various constellations located?

Constellations contain stars that are easy to pick out in the night sky. Due to this, the constellations are made up of stars from within our own galaxy, the Milky Way, as they are close enough to be seen with the naked eye. Light from individual stars in other galaxies is too dim to be seen without the use of a telescope.

Although single stars from other galaxies can't be seen with ours eye alone, some galaxies and nebula can be. For example, the Andromeda galaxy is a collection of over 1 trillion stars approximately 2.5 million light-years away. It can be seen as a fuzzy oval in the night sky, although you need a clear night in a rural area to see it.

Answered by Zoe Baily from theNational Space Centre
Image credit Hillary Mathis, N.A.Sharp, NOAO, AURA and NSF

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Are all the constellations made of stars in our own galaxy? | Space Facts - Astronomy, the Solar System & Outer Space | All About Space Magazine

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by Jonathan O'Callaghan, 27 December 2013 Where are the stars in various constellations located? Constellations contain stars that are easy to pick out in the night sky. Due to this, the constellations are made up of stars from within our own galaxy, the Milky Way, as they are close enough to be seen with the naked eye.

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What do you notice?

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What do you notice? Where are we?

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Discover the different shapes of galaxies. Use this to classify galaxies from the link below!

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Test out your ability to classify different galaxies!

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National Optical Astronomy Observatory: Galaxies

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Kitt Peak Observatory Cerro Tololo Inter-American Observatory Community Science and Data Center