Europa spouting off again

Jupiter’s moon Europa might once again be venting water into space, further supporting the idea that an ocean hides beneath its thick shell of ice, researchers reported September 26 at a news conference. 

Plumes erupting from the moon’s surface, silhouetted against background light from Jupiter, appear in several images taken by the Hubble Space Telescope in early 2014. The geysers — presumably of water vapor or ice particles — showed up in the same location as an eruption captured by Hubble in 2012 (SN: 1/25/14, p. 6). The eruptions also appear to be intermittent, appearing in only three out of 10 images. Material hovering over the moon’s southern hemisphere and absorbing ultraviolet light coming from Jupiter made the plumes visible.

“The plumes are a sign that we may be able to explore the ocean without having to drill through unknown miles of ice,” said William Sparks, an astronomer at the Space Telescope Science Institute in Baltimore. “We presume it to be water or ice particles because that’s what Europa is made of and those molecules do absorb at the wavelengths we observed,” he said. Future spacecraft could plow through the plumes and sample the water to better understand its chemistry and look for by-products of life.