Ocean Worlds (Enceladus & Europa)
Cassini saw water plumes erupt from Enceladus in 2005 and later found hydrogen and organics in them; with Europa's magnetic signature, icy moons with hidden oceans became top targets in the search for life.
Open in the interactive tree →Galileo's magnetometer showed in the 1990s that Europa has an induced magnetic field, most plausibly from a salty ocean under its ice, perhaps two to three times the volume of Earth's oceans. Cassini images from January and February 2005 revealed a plume at the south pole of Enceladus; later flybys found molecular hydrogen in 2015, pointing to hydrothermal activity (announced in 2017), then phosphates (reported 2023) and organic molecules in plume grains. ESA's JUICE launched in April 2023 and NASA's Europa Clipper on 14 October 2024, due at Jupiter in July 2031 and April 2030 respectively.
Prerequisites
- Mass Spectrometry1919Onboard mass spectrometers analysed the gas and dust thrown out by the moons.
- Deep-Space Probes (Voyager)1977Galileo and Cassini studied the Jupiter and Saturn systems for years.
Unlocks
- Finding Extraterrestrial LifeopenEnceladus and Europa are prime targets for finding life in the Solar System.