Space Crossword Puzzle

2. type of galaxy that has a flat, spinning disk with a central nucleus surrounded by spiral arms
4. all of space, time, and their contents
6. the tendency of an object to stay either at rest or in motion along a straight path
8. In 1687, argued that the orbit of the moon depended on the same type of force that causes an apple to fall on Earth
9. is a gravitationally bound system of the sun and the objects that orbit it.
11. magnified the telescope by 30 times
12. type of galaxy that has no definite shape.
14. type of galaxy that has an unusual shape, size, or composition.
16. fifth planet from the sun and is the largest

1. the force that pulls all objects towards each other
3. model with the sun in the center of the solar system- Copernicus
5. type of galaxy that lacks a central nucleus and is brighter in the center
7. name of our galaxy
10. contains more than 99.85% of the total mass of the solar system
11. a gravitationally bound system of stars, pieces of stars, gas, dust, and dark matter
13. seventh planet from the sun and spins on its side
15. model with the earth in the center of the solar system- Ptolemy