Origin of the Universe

4. consist of stars, planets, and vast clouds of gas and dust, all bound together by gravity.
6. the curved path of a celestial object
8. having or representing the earth as the center
10. the point in the orbit of the moon or a satellite at which it is furthest from the earth.
13. The motion of an object around a point, especially around another object or a center of mass
14. an elastic wave in the earth produced by an earthquake or other means.
16. a small rocky body orbiting the sun
17. The different shapes of the Moon that we see at different times of the month are called the ______ of the moon.
18. having or representing the sun as the center
19. an eclipse in which the moon appears darkened as it passes into the earth's shadow.

1. the theory that the solar and stellar systems were developed from a nebula.
2. a circle which has been squashed or flattened a bit.
3. he branch of science that deals with celestial objects, space, and the physical universe as a whole.
5. an eclipse in which the sun is obscured by the moon.
7. all of the current and past matter in the Universe came into existence at the same time, roughly 13.8 billion years ago.
9. the point in the orbit of the moon or a satellite at which it is nearest to the earth.
11. the slow change in the direction of Earth's rotational axis.
12. this is the time where Earth was first created
13. the action of rotating around an axis or center.
15. 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.