A comet's tail always points away from the sun.
2
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
If two pieces of metal touch in space, they become permanently stuck together.
808
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
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
There are more nerve cells in the human brain than there are stars in the Milky Way.
349