Cool Space Facts
Black Holes & The Speed of Light
by Elijah
Black Holes
1 Nothing can escape a black hole
Black holes have so much gravity that even light can't escape them. That's why they look totally black!
2 They are made from giant dead stars
When a really, really big star runs out of fuel, it crunches down into a tiny point with super-strong gravity. Boom — black hole.
3 Time slows down near them
If you flew close to a black hole and came back, only a little time would pass for you, but years could pass on Earth. That's real science!
4 There's one in our galaxy
Right in the middle of the Milky Way is a giant black hole called Sagittarius A*. It's about 4 million times heavier than the Sun.
5 The biggest ones are called supermassive
Some black holes are billions of times heavier than the Sun. Scientists call these monsters supermassive black holes.
The Speed of Light
1 It's the fastest thing in the universe
Light travels at 186,282 miles every second. Nothing in the whole universe goes faster.
2 It could lap the Earth 7.5 times in 1 second
If light could bend around our planet, it would zoom all the way around seven and a half times before you could blink.
3 Sunlight takes 8 minutes to reach you
The Sun is so far away that the light hitting your face right now actually left the Sun about 8 minutes ago.
4 A light-year is a distance, not a time
A light-year is how far light travels in one year — about 5.88 trillion miles. We use it to measure how far away stars are.
5 When you look at stars, you see the past
Some stars are so far away that their light took thousands of years to reach your eyes. You're literally looking back in time!