| A | B |
|---|
| The planet with the most moons | Saturn (18 moons) |
| A small celestial body with a bright nucleus and a fainter tail | comet |
| Any of the millions of small planets between the orbits of Mars and Jupiter | asteroid |
| The remnants of a meteor that does not burn up completely in Earth's atmosphere | meteorites |
| Two single stars orbiting one another | binary stars |
| The basis of comparison for measuring star mass | solar mass |
| The final stage of a star | Black dwarf |
| a fuzzy object that is not a planet but looking through a telescope, resembles a planet such as Neptune | planetary nebula |
| a huge explosion causing the death of a star | supernova |
| a small super-dense star thought to be the crushed remnants of a huge star that has exploded as a supernova | neutron star |
| an object having such strong gravity that nothing, not even light, can escape it | black holes |
| the distance that a beam of light travels in a vacuum in one year | light-year |
| the galaxy that includes our Sun and Earth; appears as a hazy white band in the night sky | Milky Way |
| a huge accumulation of stars, gas, and dust held together by gravity | galaxy |
| a celestial body that looks like a star but emits much more energy | quasar |
