Mars had an oxygen-rich atmosphere around 4 billion years ago
13
A comet's tail always points away from the sun.
2
If aliens located 60-65 million light years away from us, looked at earth through a really powerful telescope today, they would see dinosaurs!
18
The temperature of the earth's interior increases by 1 degree every 60 feet down.
115
The light hitting the earth right now is 30 thousand years old.
163
The population of the Earth has more than doubled since 1950.
151
The Sun and Moon appear to be the same size because the moon is 400 times smaller than the Sun, but 400 times closer to Earth.
13
The volume of the Earth's moon is the same as the volume of the Pacific Ocean.
178