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
If two pieces of metal touch in space, they become permanently stuck together.
808
The light hitting the earth right now is 30 thousand years old.
163
There are more nerve cells in the human brain than there are stars in the Milky Way.
349
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
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
If NASA sent birds into space they would soon die; they need gravity to swallow.
146
Earth is the only planet in our solar system that's not named after a god or goddess.
17