| A | B |
|---|
| gas giant | A gas giant is a large planet made almost entirely of gas |
| greenhouse effect | The trapping of heat by the atmosphere |
| retrograde rotation | Rotation from east to west, in the direction opposite from the usual direction |
| terrestrial planets | The first four planets from the sun |
| meteor | a streak of light in the sky produced by the burning of a meteoroid in Earth’s atmosphere |
| Comets | chunks of ice and dust whose orbits are usually very long, narrow ellipses |
| meteorite | a meteoroid hits Earth’s surface |
| Asteroid | An object that revolves around the sun, but is too small to be considered a planet. |
| Meteoroid | A chunk of rock or dust in space that usually comes from a comet or an asteroid |
| asteroid belt | The region of the solar system between the orbits of Mars and Jupiter |
| Photosphere | the layer of the sun’s atmosphere that makes light |
| Chromosphere | the layer of the sun’s atmosphere that has a reddish glow |
| corona | the layer of the sun’s atmosphere that looks like a halo during an eclipse |
| sunspot | areas of gas on the sun that are cooler than the gases around them |
| prominence | reddish loops of gas that link parts of sunspot regions |
| solar flare | explosions that occur when the loops in sunspot regions suddenly connect |
| solar wind | a stream of particles produced by the corona |
| core | the center of the sun |
| nuclear fusion | the joining of hydrogen atoms to form helium |
| Heliocentric | a description of the solar system in which all of the planets revolve around sun |
| Ellipse | an elongated circle, or oval shape |
| Inertia: | the tendency of a moving object to continue in a straight line or a stationary object to remain in place |
| Geocentric | a description of the solar system in which all of the planets revolve around Earth. |
