Astronomy

3. A huge group of single stars, star systems, star clusters, dust, and gas bound together by gravity
4. A contracting cloud of gas and dust with enough mass to form a star
6. An enormously bright, distant galaxy with a giant black hole in its center
8. An imaginary pattern in the sky
10. The spinning motion of a planet on its axis
11. A model at the solar system in which Earth and the other planets revolve around the sun
12. A stream of electrically charged particles that emanate from the sun's corona
14. A model of the universe in which Earth is at the center of the revolving planets and stars
16. The initial explosion that resulted in the formation and explosion of the universe
18. The small, dense remains of a high-mass star after a supernova
21. The tendency of an object to resist any change in its motion
22. The central region of the sun, where nuclear fusion takes place
23. A large cloud of gas and dust in space

1. The blue-whitish core of a star that is left behind after its other layers have expanded and drifted out into space
2. The force that pull objects toward each other
4. One of the small asteroid-like bodies that formed the building blocks of the planets
5. Matter that does not give off electromagnetic radiation but is quite abundant in the universe
7. The study of the moon, stars, and other objects in space
8. The outer most layer of the sun's interior
9. A dark area of gas on the sun's surface that occurs when the loop in sunspot regions suddenly connect
13. The brilliant explosion at a dying super giant star
15. A huge, reddish loop of gas that protrudes from the sun's surface linking parts of sunspot regions
17. An object whose gravity is so strong that nothing, not even light, can escape
19. All of space and everything in it
20. The movement of an object around another object