- Neutron stars can spin at a rate of 600 rotations per second.
2. Space is completely silent
3. There is an uncountable number of stars in the known universe
4. The Apollo astronauts' footprints on the moon will probably stay there for at least 100 million years
5. 99 percent of our solar system's mass is the sun
6. More energy from the sun hits Earth every hour than the planet uses in a year
7. If two pieces of the same type of metal touch in space, they will bond and be permanently stuck together
8. The largest asteroid in our solar system is a mammoth piece of space rock named Ceres
9. One day on Venus is longer than one year.
10. Jupiter's Red Spot is shrinking
11. One of Saturn's moons has a distinct two-tone coloration
12. Spacecraft have visited every planet
13. Number of active communicative extraterrestrial civilizations in the Milky Way galaxy.
