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Ch. 2 Study Stack
Astronomy
| Term | Definition |
|---|---|
| moon | a natural satellite that revolves around a planet |
| orbit | the path of an object as it revolves around another object in space |
| ellipse | an elongated circle, or oval shape; the shape of the planets' orbits |
| inertia | an object will stay still or keep moving at the same speed in the same direction until a force acts upon it |
| gravity | its strength depends on mass and the distance between objects |
| sun | our star that produces heat and light (energy!) |
| star | the sun is the only one of these in our solar system |
| planet | a spherical object that revolves around the sun with nothing else in that orbital path |
| terrestrial planets | the name given to the 4 inner planets: Mercury, Venus, Earth, & Mars |
| greenhouse effect | the trapping of heat by a planet's atmosphere |
| gas giants | the name given to the 4 outer planets: Jupiter, Saturn, Uranus, and Neptune |
| dwarf planet* | a large, spherical object that revolves around the sun with other things in that orbital path |
| comet | a ball of ice and dust whose orbit is a long, narrow ellipse. |
| asteroid | larger rocks (not spheres) that revolve around the sun |
| asteroid belt | the region of the solar system between the orbits of Mars and Jupiter |
| meteoroid | smaller rocks (not spheres) that revolve around the sun |
| meteor | a streak of light in the sky produced by the burning of a meteoroid in Earth's atmosphere |
| meteorite | a meteoroid that has hit Earth's surface |
| Oort Cloud | the sphere that surrounds the sun; it is full of every solar system object that is attracted to the sun because of its massive gravity |
| Kuiper Belt | a ring of rocky and icy objects revolving around the sun outside of Neptune's orbit |