space

1. - A celestial object consisting of a nucleus of ice and dust and, when near the sun, a "tail" of gas and dust particles pointing away from the sun.
5. - The study of the origin, evolution, and eventual fate of the universe.
7. - A planet that orbits a star outside of our solar system.
8. - Relating to the sun or the solar system.
9. - An exploding star, resulting in a sudden brightening of the star.
11. - Relating to the moon.
12. Hole - A region of spacetime where gravity is so strong that nothing, not even light, can escape.
16. - A celestial body orbiting around a planet or star.
17. - The path followed by a celestial body around another under the influence of gravity.
18. - A vast system of stars, gas, and dust bound together by gravity.

2. Way - The galaxy containing our solar system.
3. - A group of stars forming a recognizable pattern.
4. - A person trained for traveling in space.
6. - A celestial body that orbits a star and has cleared its neighboring region of other objects.
8. - A luminous celestial body consisting of a mass of gas held together by its own gravity.
10. - A cloud of gas and dust in space, where stars are born.
13. - Relating to the sky or outer space.
14. - All existing matter, energy, and space regarded as a whole.
15. - The scientific study of celestial objects such as stars, planets, comets, and galaxies.
18. - The force that attracts objects with mass towards each other.