| A | B |
|---|
| summer solstice | longest day of the year |
| winter solstice | shortest day of the year |
| equinox | when day and night are equal lengths |
| asteroid | a rock that orbits the sun |
| comet | ball of ice and dust that orbits the sun |
| meteor | rock that burns up in the earth's atmosphere |
| meteorite | a space rock that reaches the earth's surface |
| supernova | the explosion of a dying star |
| nebula | a large cloud of many stars and galaxies |
| eclipse | when one object moves over another |
| constellation | a grouping of stars |
| luminosity | the brightness of a star |
| perihelion | when the earth is closest to the sun on its orbit |
| aphelion | when the earth is fruthest from the sun on its orbit |
