| A | B |
|---|
| SETI | organization that uses radar dishes/radio satellites to search for extraterrestrial life |
| Kepler | spacecraft launched to look for Earth-like planets around other stars |
| comet | ball of ice, dust and frozen gasses |
| binary stars | two stars that orbit each other in space |
| star cluster | group of three or more stars |
| aurora | lights in the sky caused by solar wind hitting our magentosphere |
| solar wind | stream of particles leaving the sun |
| meteor | streak of light caused by a rock from space burning up as it falls through our atmosphere |
| meteorite | rock from space that survives the trip through the atmosphere and lands on the ground |
| meteoroid | rock moving through space |
| Voyager I | spacecraft launched in 1977 to study the solar system and has officially left our solar system |
| prominences | huge arching columns of gas caused by the magnetic field associated with sunspots |
| sun spot | darker, cooler area of the sun |
| photosphere | innermost layer of the sun's atmosphere that produces light |
| corona | outermost part of the sun's atmosphere where particles escape as solar wind |
| astronomical unit | the distance the Earth is from the sun, 93 million miles or 150 million km |
| Drake Equation | equation that estimates how many intelligent, communicating civilizations we have in our galaxy |
| coma | cloud of gases around the solid portion of a comet |
| Europa | Jupiter's moon where scientists hope to search for signs of life because it is covered in ice and may have underwater volcanoes as a power source |
| asteroid belt | belt of rocks in space between Jupiter and Mars |
