Space is amazing! Here are ten cool facts about space.

1) One million Earths could fit inside the Sun. The Sun is an average-size star.

2) For years, people thought Earth was the only planet with water. NASA found proof of running water on Mars too.

3) Comets are leftovers from the beginning of our solar system. They formed 4.5 billion years ago. They are made of sand, ice, and carbon dioxide.

4) You cannot walk on Jupiter, Saturn, Uranus, or Neptune. They have no solid surface.

5) If you flew a plane to Pluto, it would take more than 800 years.

6) Space junk is human-made trash in space. It orbits Earth but is no longer useful. There are about 500,000 pieces. Many are fragments from rockets and satellites. Even a spanner from the space station is space junk.

7) A car-sized asteroid hits Earth's atmosphere once a year. It burns up before it reaches us.

8) The tallest mountain we know is on the asteroid Vesta. It is 22 kilometers high. That is three times the height of Mount Everest.

9) There are more stars in the universe than grains of sand on all beaches. That is at least a billion trillion stars.

10) The sunset on Mars looks blue.

Space is full of surprises!