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
It takes a photon 170,000 years to travel from the core of the Sun to the surface, but only 8 minutes to travel the rest of the way to Earth.
6
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
In the last 7 years, humanity has discovered 43 potentially habitable planets.
14
One pinhead of the sun's energy is enough to kill a person at a distance of 160 kilometers.
277
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
The light hitting the earth right now is 30 thousand years old.
163