In the 15th century and later European explorers go into the deep sea, far away from a coast, using the knowledge left by the Arabian golden age, developed new ships, used instruments like the compass, astrolabe, the quadrant, etc., and make nautical science a real source of development and prosperity.

Archaeoastronomy is the study of how people have understood, conceptualized and used the phenomena in the sky and what role the sky played in their cultures, by analysing their material remains.

According to the historical and ethnographic records, most (if not all) societies have looked up at the sky and related to it. The stories, myths, art, religious beliefs, rituals and symbolism of many cultures are associated with the Sun, the Moon, stars and planets. In most cases where texts and/or academic ethnographic works were found, this is easily verifiable. However, when a study extends further back into prehistory (before writing), researchers have to rely on the remains and ruins left behind. In this case, the research is based on the archaeological record which is used to reveal an ancient society’s notion to the celestial sphere and its objects.

Archaeoastronomy therefore focuses on the material elements present in the archaeological record. For instance, it can recognise whether particular structures (houses or monuments) were intentionally built in such a way as to capture sunlight on particularly important days of the year.

Step 3 : Set your location. The default location is Paris, France. Press F6 or click on the appropriate icon in the left tool bar to open the Location Window.You can select your location by clicking on the map, by searching for a nearby city, or by entering your longitude, latitude and altitude manually by creating a new location.

Step 4: Set the time to 10 p.m.. of 1st March 2017. „J” slows down or reverses speed, „L” increases time speed, and „K” makes time return to normal speed. You can also use the time control buttons in the lower right of the screen.

Step 5: Play with the view options. Try clicking the buttons in the bottom toolbar, which will appear if you roll the mouse cursor over the status bar at the bottom left of the screen.

Step 6: Look around and select an object in the sky. Press F3 to open the search window. You can type in the name of a star, planet, constellation or nebula. As you type a list of matching objects is shown. Pressing TAB selects the next item in the completion list. Press RETURN or click the button in the search window to go to the object.

Step 7: Now, go to the North direction. When the „N” is in the middle of your screen, go to the bottom toolbar and select the „constellations line” (first option). Find Ursa Major constellation . Then, click on „Print screen”. Paste the image on a document (word document).

Step 8: Set the time to 0 a.m.. of 2nd March 2017. Go to the North direction. When the „N” is in the middle of your screen, go to the bottom toolbar and select the „constellations line” (first option). Try to find Ursa Major constellation. Then, click on „Print screen”. Paste the image on a document (word document). Do the same for 2 a.m.

Step 9: Compare the three images. What do you wish to highlight? Can you share your thoughts and comment on the padlet below?

Step 10: (Optional) If you have the chance, go outside and take a picture of Ursa Major constellation. Post it on Paddlet with your comments on the activity. If you live in a city, with high light pollution , you may comment on that, too. 

 Prestigiacomo Maria Grazia,Italy

 I discover the importance of The Inquiry based learning approach. In the two videos  the teachers have stressed the importance of learning by doing and how through this approach students are also actively involved  and collaborate ,make hipothesis and ceck them, share their ideas.The thing that struck me the most is that both teachers spoke of growth, change and enrichment not only of students but also of themselves. So I think that I can apply all the things I mentioned above because the result are excellent.

 

I choose an image of the bounty because I identify with navigation  a voyage by sea, then because I like very much  the sailing ships and especially the Bounty of which I have seen  the movie "Mutiny of the bounty " finally because the journey had a mission botany : the ship had to cross the globe to reach Tahiti, collect some specimens of breadfruit and transport them in the Caribbean.

Lines of longitude, or meridians, are drawn a little differently. The line of longitude corresponding to 0º, which passes through Greenwich in London, is called the Prime (or Greenwich) Meridian. Longitude lines run along the Earth’s surface in a north–south direction, and unlike latitude lines, they divide the globe into segments like those of an orange, rather than regular strips.

HOW TO MEASURE LATITUDE
It's possible to measure latitude by comparing your position on Earth with the position of either the sun or the North Star (Polaris). Measurements using the sun are possible on a clear day in the northern or southern hemispheres, when the sun is easy to find. However, measurement of latitude isn't as straightforward as you might think. Accurate readings can only be taken at noon, when the sun is at its highest in the sky. To complicate matters further, the sun rises higher in summer than in winter, and this must be allowed for in any calculation.

Being so far away and only one of a myriad stars visible to the naked eye, the North Star isn't as easy to find as the sun. Furthermore, you can only see it at night, which isn't always convenient. Its major limitation, however, is that it isn't visible from the southern hemisphere.

For our purposes, we shall therefore assume that we're in the northern hemisphere. You can use a simple quadrant to measure latitude using either the sun or the North Star. Both methods are described below.

Once you've found the North Star it's simple to determine your latitude.

It’s easy to work out your longitude using a radio, watch and sundial, but as castaways on Capraia we had none of these. Even though we built a radio, we still needed some sort of timepiece, so we made a pendulum of a certain, known length which we knew would swing with a fixed frequency (determined by this length).

The Earth rotates one full turn (360º of longitude) in one day. It therefore turns one degree of longitude in 1/360th of a day, or every four minutes. To calculate your longitude, you therefore simply need to work out the time difference between noon at your location and noon at the Prime Meridian.

The Prime Meridian is the imaginary line running between the North and South Poles that’s used to indicate 0º longitude. It passes through Greenwich in southeast London, and is therefore sometimes referred to as the Greenwich Meridian.

An international conference held in Washington D.C. in 1884 designated ‘the meridian passing through the centre of the transit instrument at the Observatory of Greenwich as the initial meridian for longitude.’ During the 1950s, the Greenwich Observatory moved to Herstmonceux Castle in East Sussex, where the skies were deemed to be clearer. In 1990, it moved again, to the Institute of Astronomy at the University of Cambridge, but the original site in Greenwich continues to serve as the location for 0º longitude.

As the prime meridian, the north–south line at Greenwich is used as the reference point for all other meridians of longitude, which are numbered east or west of it. The current system employs 24 standard meridians of longitude 15º apart, starting with the Prime Meridian.

The lines all run from the North to the South Pole, at right angles to the Equator. These meridians are the centres of 24 standard time zones. In theory, standard time becomes successively one hour earlier at each 15º longitude west of the Prime Meridian, and one hour later at each 15º longitude east. Time is the same throughout each zone. In practice, many of the zones have been subdivided or their shape altered for convenience.

The mean solar time at Greenwich is now called Universal Time (formerly called Greenwich Mean Time or GMT).

 

Galileo will give precise indications of position in real time, supporting in car navigation, aviation and maritime transport, assisting precision farming and security companies (by monitoring stolen vehicles, for example), helping local public transports, tourist guides and blind or poorly sighted people finding their way.

An important application of Galileo is the global Search and Rescue (SAR) function, which assists rescue teams in finding people in trouble, while giving real-time feedback to the users. 

What if you got in trouble or not feeling well? Galileo comes to the rescue! The satellite system provides solutions and support for people who are in a critical situation.Applications of Galileo ensures safety for people on Earth, but not only that. It can be useful for solving everyday challenges that involve positioning. In November 2017 four satellites of Galileo constellation will be launched from Kourou, French Guiana. Arianespace will use an Ariane 5 rocket to put on orbit four (number 19-22) Galileo full operational capability satellites for Europe’s Galileo navigation constellation.