Astronomy Crossword

2. the _______ theory, the cosmic explosion that is theorized to have started the universe
4. the branch of science that deals with celestial objects, space, and the physical universe as a whole
6. the apparent displacement of a nearby star that results from the motion of Earth around the Sun
7. any of the larger objects revolving about the Sun or any similar objects that orbit other stars
8. National Aeronautics and Space Administration
10. _______ explored the outer Solar System aided by gravity assist
12. “Shooting star”
14. with his telescope, _____ was able to carry out the test of the Copernican theory
15. centered around the sun
18. NASA's ambitious visible light space telescope, launched in 1990
20. any planetary body that is outside the solar system and usually orbits a star other than the sun
21. Our nearest star
22. the closest galaxy to the Milky Way
23. 9,500,000,000,000 kilometers (the distance ______ can travel in a year)

1. our home galaxy
3. two objects exert a force of attraction on one another known as _________.
5. a region of space resulting from the collapse of a star with an extremely high gravitational field
6. A special theater in which we project a simulation of the stars and planets onto a white dome
9. Annual prizes given in a variety of sciences, literature, and peace
11. The Big Dipper is an asterism within the ____ of Ursa Major
13. Centered on Earth
16. the first artificial satellite to orbit Earth, launched in 1957
17. a rapidly spinning neutron star that emits radiation, usually radio waves, in narrow beams
19. a natural satellite such as Earth's luna or Saturn's Titan