In order to reinforce the learning of new contents related to the 1st unit in Social Science, we leave here some links courtesy of NASA. Some of them are really funny:

Make your own planet. You can even download an image of it:
http://planetquest.jpl.nasa.gov/system/interactable/1/index.html

Plan an interstellar trip using different means of transport: (find out how long could be travelling to Saturn by car…)
http://planetquest.jpl.nasa.gov/system/interactable/5/index.html

This is how scientist are able to find previously unknown planets:
http://planetquest.jpl.nasa.gov/system/interactable/11/index.html

A very interesting timeline that explains the most important discoveries about the Universe throughout history:
http://planetquest.jpl.nasa.gov/system/interactable/2/timeline.html

If there have been times when you have wondered what you might weigh on another planet, here you can calculate it. Some numbers can be really awesome! Check it out:

http://www.exploratorium.edu/ronh/weight/

Enjoy them!