From the nitrogen in our DNA, to the calcium in our teeth, the iron in our blood, to the carbon in our apple pies - all were made in the interiors of collapsing stars; we're all made of stardust.
22
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
The last time that the Sun was in its current position in space around the Milky Way, dinosaurs ruled the Earth.
10
There is a mysterious and loud radio signal known as 'the space roar' that has yet to be explained.
15
Pluto is smaller than Russia.
9