Of Titan and Methane

A new study seeks to list out the circumstances under which biological sources of methane should be considered when it comes to rocky worlds.

IMAGE: Methane in a planet’s atmosphere may be a sign of life if nonbiological sources can be ruled out. This illustration summarizes the known abiotic sources of methane on Earth, including outgassing from volcanoes, reactions in settings such as mid-ocean ridges, hydrothermal vents, and subduction zones, and impacts from asteroids and comets. CREDIT: 2022 Elena Hartley

There is a place where planetary science and astrobiology start to cross over, and that is generally where we start questioning just how to go about finding life on other worlds. So far, we…