| A | B |
|---|
| reflection | The bouncing of light off a surface; a way to gather and focus light. |
| refraction | The bending of light as it passes from one material to another; a way to gather and focus light. |
| spectroscope | An instrument that separates light into a pattern of lines of different colors. |
| galaxy | A group of billions of stars, dust, and gases in space held together by gravity. |
| constellation | Stars that appear to be in groups when viewed from Earth. |
| light year | The distance light travels in one year. |
| metorite | A piece of meteoriod that lands on Earth after passing through the atmosphere. |
| comet | A ball of ice, dust, and gases that travels through space and orbits the sun. |
| meteor | A bright streak of light that passes through the Earth's atmosphere. |
| meteroid | A small piece of rock or metal that travels in space around the sun. |
| asteroid | A rocky object that revolves around the sun. |
| model | A representation of how something looks or works. |
| elliptical | Oval shaped like a flattened circle. |
| digit | A symbol used to write numbers. |
| period | A 3-digit group of numbers separated from other groups by a comma. |
