1: 1. The universe is expanding at an accelerating rate, thanks to dark energy.

2: 2. Black holes are so dense that not even light can escape their gravitational pull.

3: 3. There are more stars in the universe than grains of sand on all the Earth's beaches.

4: 4. The Sun is just one of billions of stars in our Milky Way galaxy.

5: 5. Space is a near-perfect vacuum, with almost no air to conduct sound waves.

6: 6. The surface temperature of Venus can melt lead!

7: 7. A day on Venus is longer than a year on Venus.

8: 8. The International Space Station travels at a speed of 17,500 miles per hour.

9: 9. The oldest known object in the universe is a star cluster named M13, which is about 14 billion years old.