Astronomy

4. The tendency of an object to resist any change in its motion
5. The blue-whitish core of a star that is left behind after its other layers have expanded and drifted out into space
8. An imaginary pattern in the sky
10. A stream of electrically charged particles that emanate from the sun's corona
11. The small, dense remains of a high-mass star after a supernova
15. A contracting cloud of gas and dust with enough mass to form a star
17. One of the small asteroid-like bodies that formed the building blocks of the planets
18. The central region of the sun, where nuclear fusion takes place
19. A large cloud of gas and dust in space
21. The movement of an object around another object
23. A huge group of single stars, star systems, star clusters, dust, and gas bound together by gravity

1. An object whose gravity is so strong that nothing, not even light, can escape
2. The outer most layer of the sun's interior
3. The force that pull objects toward each other
6. A model at the solar system in which Earth and the other planets revolve around the sun
7. An enormously bright, distant galaxy with a giant black hole in its center
9. A dark area of gas on the sun's surface that occurs when the loop in sunspot regions suddenly connect
10. The brilliant explosion at a dying super giant star
12. The study of the moon, stars, and other objects in space
13. Matter that does not give off electromagnetic radiation but is quite abundant in the universe
14. A model of the universe in which Earth is at the center of the revolving planets and stars
16. The spinning motion of a planet on its axis
17. A huge, reddish loop of gas that protrudes from the sun's surface linking parts of sunspot regions
20. The initial explosion that resulted in the formation and explosion of the universe
22. All of space and everything in it