Solar system

3. a person trained, equipped, and deployed by a human spaceflight program to serve as a commander or crew member aboard a spacecraft.
5. the fourth planet from the Sun – a dusty, cold, desert world with a very thin atmosphere.
8. an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing.
9. Earth's closest planetary neighbor and the hottest planet in our solar system.
12. the fifth planet from the Sun and the largest in the Solar System.
13. was discovered in 1781 by astronomer William Herschel
14. the only place in the known universe confirmed to host life.
15. a streak of light in the sky caused by a meteoroid crashing through Earth's atmosphere.

1. the smallest planet in the Solar System.
2. a 4.5 billion-year-old star – a hot glowing ball of hydrogen and helium at the center of our solar system.
4. the eighth and farthest-known Solar planet from the Sun.
6. Earth's only natural satellite
7. the farthest planet from Earth that's visible to the naked human eye, but the planet's most outstanding features — its rings — are better viewed through a telescope.
10. a vehicle or machine designed to fly in outer space.
11. a dwarf planet that lies in the Kuiper Belt.