| A | B |
|---|
| aurora | sheets of colored light produced by a magnetic storm in the earth's upper atmosphere |
| chromosphere | thin layer of the sun's atmosphere that lies above the photosphere and glows with a reddish light |
| convective zone | region around the sun's radiative zone in which moving gases transfer energy |
| corona | outermost layer of the sun's atmosphere |
| moon | body that is smaller than a planet and orbits the planet |
| nebular theory | theory tht the sun and the planets condensed out of a spinning cloud of gas and dust |
| photosphere | innermost layer of the solar atmosphere |
| planet | any one of the nine major bodies that orbit the sun |
| planetestimal | small body of matter that formed in the outer regions of the solar nebula while the sun was forming in its center |
| prominence | cloud of glowing gases that arches high above the sun's surface |
| protoplanet | large body of matter that formed from the coalescenceof planetesimals in the solar nebula |
| radiative zone | region surrounding the core of the sun in which energy is transferred in the form of electromagnetic waves |
| solar flare | sudden, violent eruption of electrically charged atomic particles from the sun's surface |
| solar nebula | cloud of gas and dust that developed into the solar system |
| solar system | the sun and the bodies that revolve around it |
| solar wind | electrically charged atomic particles that stream out into space through holes in the sun's corona |
| sunspot | cool, dark area of gas within the photosphere caused by powerful magnetic fields |
| sunspot cycle | periodic variation in the number of sunspots that occurs approximately every 11 years |
