Match the following vocabulary words with their definitions.
1. An oval having both ends alike,
revolution
2. The natural force that makes objects move or tend to move toward each other,
orbit
3. The path of the Earth or any planet around the sun,
ellipse
4. To move around a center or axis ,
perihelion
5. Instrument for making distant objects appear nearer, larger, and brighter ,
aphelion
6. The point in a planet's orbit that is farthest from the sun ,
treatise
7. The point in a planet's orbit that is nearest the sun ,
telescope
8. Movement around some point in a circle or curve ,
rotate
9. A formal written work dealing with some subject ,
gravity