| Flap 1 |
Flap 2 |
| a description of the solar system in which all of the planets revolve around Earth | geocentric system |
| process by which heat is trapped in the atmosphere by water vapor, carbon dioxide, methane, and other gases that form a "blanket" around the earth | greenhouse effect |
| the name given to the first four outer planets: Jupiter, Saturn, Uranus, and Neptune | gas giants |
| the region of the solar system between the orbits of Mars and Jupiter, where many asteroids are found | asteroid belt |
| objects revolving around the sun that are too small and too numerous to be considered planets | asteroids |
| the middle layer of the sun's atmosphere | chromosphere |
| a ball of ice and dust whose orbit is a long, narrow ellipse | comet |
| the central part of the sun, where nuclear fusion occurs | core |
| the outer layer of the sun's atmosphere | corona |
| an elongated circle, or oval shape; the shape of the planets' orbits | ellipse |
| the tendency of a moving object to continue in a straight line or a stationary object to remain in place | inertia |
| a streak of light in the sky produced by the burning of a meteoroid in Earth's atmosphere | meteor |
| a meteoroid that has hit Earth's surface | meteorite |
| a chunk of rock or dust in space | meteoroid |
| the spinning motion of a planet from east to west, opposite to the direction of rotation of most planets and moons | retrograde rotation |
| the combining of two atomic nuclei to produce a single larger nucleus as when two hydrogen atoms join together to form helium, releasing energy | nuclear fusion |
| a dark, cooler region on the surface of the sun | sunspot |
| a loop of gas that protrudes from the sun's surface, linking parts of sunspot regions | prominence |
| an explosion of hydrogen gas from the sun's surface that occurs when loops in sunspot regions suddenly connect | solar flare |
| a stream of electrically charged particles produced by the sun's corona | solar wind |
| the name given to the four inner planets: Mercury, Venus, Earth & Mars | terrestrial planets |
| the spinning motion of a planet about its axis | rotation |
| the movement of an object around another object | revolution |
| a large planetary system that consists of a combination of many smaller planetary systems and objects | solar system |
