Published on : May 15, 2018
A new look at old data is giving scientists a fresh reason to view Europa, a moon of Jupiter, as a leading candidate in the search for life beyond Earth, with evidence of water plumes shooting into space. Signatures in some Hubble Space Telescope images have been associated with putative water plumes rising above Europa’s surface, providing support for the ocean theory. The study, published Monday in the journal Nature Astronomy, adds to the mounting evidence that Europa is spewing its contents into space.
Given the suspected abundance of warm, liquid water under its kilometres-thick ice shell, the moon is considered a "top candidate" by US space agency Nasa for life on a Solar System body other than Earth.
But sending a robot craft to land on Europa and drill through its surface would be a much more costly and complicated endeavour than, say, flying through a plume of water ejected from the moon’s innards, and measuring its composition.
Nasa has reported evidence twice before, from its Hubble Space Telescope, for the existence of water plumes on Europa, though this interpretation has caused much debate.
Europa is considered among the prime candidates for life in our solar system, but is not the only one. For example, NASA's Cassini spacecraft sampled plumes from Saturn's ocean-bearing moon Enceladus that contained hydrogen from hydrothermal vents, an environment that may have given rise to life on Earth.
A bit smaller that Earth's moon, Europa's ocean resides under an ice layer 10 to 15 miles (15 to 25 km) thick, with an estimated depth of 40 to 100 miles (60 to 150 km).