Scientists have found evidence of a liquid water ocean swirling under the icy shell of Jupiter’s moon Europa, Nasa announced on Monday, with new evidence of water plumes bursting out into space. Scientists first reported the behaviour in 2013 using the Hubble telescope, but have now made a follow-up sighting.
It is significant because Europa, with its huge subsurface ocean of liquid water, is one of the most likely places to find microbial life beyond Earth.
Hubble made its latest identification by studying Europa as it passed in front of Jupiter.
The telescope looked in ultraviolet wavelengths to see if the giant planet’s light was in any way being absorbed by material emanating from the moon’s surface. Ten times Hubble looked and on three of those occasions it spied what appeared to be “dark fingers” extending from the edge of Europa.
With Jupiter as a bright light behind the moon, the scientists observed Europa in silhouette, and with ultraviolet light saw what appeared to be evidence of the plumes.
“If plumes exist, this is an exciting find,” lead researcher said. “It would allow us to search for signs of life without having to drill through miles of ice”, he added.
Nasa scientists have been working on proposals for a Europa mission for 15 years, and has a tentative plan to send a spacecraft on a flyby near the moon in the 2020s, zipping past its intense, electronics-frying radiation field.