THE BEGINNING

2. made up of spheroid plasma that is held up together tightly with the help of its gravitational force
4. a natural celestial object that is characterized by an orbit around a planet of the Solar System
6. remotely controlled roving vehicles that carried television cameras and instruments to measure the physical and chemical properties of the lunar soil
8. capability of being inhabited
10. vast cosmic islands of stars, gas, dust, and dark matter held together by gravity
11. the Greek word for "life"
13. the flight spare, or backup vehicle for the sojourner rover that operated on Mars in 1997
14. a vehicle that travels across the surface of a planet, moon, or other astronomical objects.
16. a planet outside the solar system
18. the center or most important part of something
19. an online database of potentially habitable worlds discoveries; an acronym

1. life outside of Earth
3. a region around a magnetic material within which the force of magnetism acts.
5. the force that attracts a body toward its center
6. also known as "Geosphere"
7. small, rocky, objects that orbit the Sun
9. a place in space where gravity pulls so much that even light cannot get out
12. a hard outer layer of something
15. one of the two theories about the origin of the Earth
17. a frozen leftover from the formation of the solar system that is composed of dust, rock, and ices