NASA Hubble Telescope Discovers Water Plumes Over Icy Europa

NASA's Hubble Space Telescope has made some surprising discoveries when it comes to Jupiter's moon, Europa. It's spotted water vapor above the moon's frigid south polar region, providing the first strong evidence of water plumes erupting off the moon's surface.

The findings aren't completely surprising. Scientists had previously detected evidence of an ocean under Europa's icy crust. It's very possible that this water vapor is generated by erupting water plumes on the surface.

"By far the simplest explanation for this water vapor is that it erupted from plumes on the surface of Europa," said Lorenz Roth, one of the researchers, in a news release. "If those plumes are connected with the subsurface water ocean we are confident exists under Europa's curst, then this means that future investigations can directly investigate the chemical makeup of Europa's potentially habitable environment without drilling through layers of ice. And that is tremendously exciting."

This would actually be the second moon in the solar system known to have water vapor plumes. The first one to be discovered was Saturn's moon Enceladus. First detected in 2005 by NASA's Cassini orbiter, the plumes also possess dust and ice particles. So far, though, only water vapor gases have been detected in Europa.

"We pushed Hubble to its limits to see this very faint emission," said Joachim Saur, one of the researchers, in a news release. "These could be stealth plumes, because they might be tenuous and difficult to observe in the visible light."

It's possible that these plumes could be vented from long cracks on Europa's surface, known as lineae. Cassini has actually seen similar fissures that host the Enceladus jets. In addition, it seems that the Europa plumes are similar to Enceladus in another way. They seem to also vary depending on the moon's orbital position; active jets have only been seen when Europa is farthest from Jupiter.

"The apparent plume variability supports a key prediction that Europa should tidally flex by a significant amount if it has a subsurface ocean," said Kurt Retherford, one of the researchers, in a news release.

The findings reveal a little bit more about the surface of Europa. More specifically, they pave the way for future investigations and findings. Once the plumes are confirmed, scientists can take a closer look at their composition and may even be able to find out more about the potential subsurface sea of Europa. This, in turn, could tell researchers whether or not the conditions could support life.