Mars had an oxygen-rich atmosphere around 4 billion years ago
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Earth is the only planet in our solar system that's not named after a god or goddess.
17
A neutron star (what remains after a Super Nova) is so dense that a portion of it the size of a sugar cube would weigh as much as all of humanity, or more than all the cars in the United States.
5
The temperature of the earth's interior increases by 1 degree every 60 feet down.
115
Sound doesn't travel in space.
255
There's a mysterious dwarf planet between Mars and Jupiter called 'Ceres' which has never been visited by spacecraft or photographed in detail, however, Earth-bound telescopes reveal a large bright shining spot on the surface of this planet, the origin and nature of which are unknown.
5