The relative quantities of volatile gases like methane and ethane can reveal key details about distant Kuiper Belt objects.

which originate in the Kuiper Belt, the doughnut-shaped region of icy bodies beyond the orbit of Neptune. Related: Where does the solar system end? Unlike the supposedly water-rich ice giants ...

Neptune, for example ... However, when analyzing planetesimals in the Kuiper belt—of which the notoriously demoted Pluto is a ...