Water ice and water vapour have been detected on the Moon, Mars, comets and several icy moons. Scientists have also found water-related molecules in distant planetary systems. Liquid surface oceans like Earth’s are much harder to confirm.
What we found
Water is common in space, but it appears in many forms and environments. Permanently shadowed lunar craters can preserve ice. Mars has polar ice and evidence of ancient rivers. Europa and Enceladus probably hold oceans beneath ice. Finding water does not automatically mean finding life, because life also needs suitable chemistry, energy and long-term conditions. The Ridbusters then compare the wording with the original sources, look for the conditions of each observation and check whether another explanation could fit. That turns a surprising headline into a trail a young investigator can follow: claim, test, result and remaining uncertainty. Water ice and water vapour have been detected on the Moon, Mars, comets and several icy moons.