Yesterday, the long-hypothesized existence of water vapor jets on Europa has finally been confirmed. Its impact on astronomy? Free alien steam soup for everyone in the next few decades.
It has been theorized that, much like the similar icy moon Enceladus of Saturn, Jupiter’s moon Europa could be spewing out jets of water vapor from its surface. There has been no direct observation of this phenomenon, however, even after we have visited Jupiter’s moon system with several mission probes.
Yesterday, all of this changed with the finalized confirmation of an almost 3-year-old instrumental observation. From February 2016 to March 2017, a team of researchers used NASA’s Hubble Space Telescope to study Europa for 17 separate days. Sometime during April 26, 2016, a strong signal indicating the infrared signature of water vapor was observed on the moon. What was later presumed to be a single jet plume was estimated to have a mass of approximately 23,000 tons. Relatively small for the moon, but big enough to catch the attention of its fellow neighboring Earthlings.
This single observation marks the first direct experimental evidence of the possibility of Europa’s subsurface liquid ocean. Up until this point, astronomers have only hypothesized this notion based on its orbital data, the existence of other similar satellite bodies (such as Enceladus), as well as the external composition of the elusive Saturnian moon.
But more importantly, however, the team of researchers has discovered that these phenomena do not happen often. the plume observed was only one of the sporadic jet plume events that happen on the surface of Europa. This means that our astronomers are dealing with something very different compared to Enceladus, which experiences similar jet plumes almost non-stop at its South Pole.
So, how exactly will this discovery change things in astronomy? It has already been long proposed before that these jet plumes would provide very vital data about the interior of the icy moons that have them. As such, instead of immediately embarking on a very expensive mission to drill into the surface of Europa to search for its subsurface ocean, it would be better to scoop up this “free alien steam” first, in order for us to get an easier preliminary observation of what might be found below.
In fact, NASA’s upcoming Europa Clipper mission may just have its mission layout changed with this new discovery. It could include in its scheduled flybys one or two attempts to get to these plumes to collect samples, either to be directly measured by onboard instruments, or be sent back here to Earth for further analysis.