Mars had an oxygen-rich atmosphere around 4 billion years ago
13
The light hitting the earth right now is 30 thousand years old.
163
Sound doesn't travel in space.
255
Not only are there rogue planets floating through space completely alone, not orbiting any stars, but it’s possible that these pitch-black lonely planets support life.
14
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 sun puts out more power in 1 second than mankind has ever used within human existence.
14