[[Comets]] are chunks of dust and ice. Some are in an [[ellipse|elliptical]] orbit around the sun, meaning that they will return someday. Some are in a [[hyperbola|hyperbolic]] orbit around the sun, meaning that they will only come into the solar system once and will never return. | [[Comets]] are chunks of dust and ice. Some are in an [[ellipse|elliptical]] orbit around the sun, meaning that they will return someday. Some are in a [[hyperbola|hyperbolic]] orbit around the sun, meaning that they will only come into the solar system once and will never return. |