Space Exploration

3. "NASA program that landed the first humans on the Moon."
6. "A bowl-shaped cavity on the surface of a planet or moon, typically caused by an impact."
7. "A vehicle designed to propel itself by ejecting exhaust gas from one end."
8. "The force that attracts a body toward the center of the earth, or toward any other physical body having mass."
10. "An artificial object placed into orbit around a planet."
12. "The first artificial Earth satellite."
13. "A space station, or a habitable artificial satellite, in low Earth orbit."
14. "A robotic vehicle exploring another planet's surface."
15. "The Red Planet."

1. "A massive system of stars, stellar remnants, interstellar gas, dust, and dark matter."
2. "An icy small Solar System body that, when passing close to the Sun, warms and begins to release gases."
4. "Path of a celestial body around a planet or star."
5. "An instrument used to observe distant objects in space."
9. "A hypothetical or fictional being from another world."
11. "A person trained to travel in a spacecraft."