A group of #NASA scientists announced that 15 months worth of observations from the #Hubble Space Telescope might have detected water plumes erupting from beneath the ice crust of #Europa, a moon of Jupiter thought to contain a subsurface ocean. The ocean, scientists theorize, is warmed by tidal forces exerted by Jupiter. If that ocean contains organic material, it might contain extraterrestrial life.
The original mission was to ascertain whether Europa has an atmosphere by allowing the light of Jupiter to shine through it allowing the Hubble’s spectrographic instruments to verify whether the atmosphere exists and what it is comprised of. The scientists conducting the study also noted on three different occasions indications of water plumes erupting through the surface of Europa. The plumes, seen by the Hubble as silhouettes, stretched 125 miles above the surface of Jupiter’s moon.
The findings match an earlier observation by the Hubble in 2012 of water plumes erupting from Europa’s south polar area. While scientists are unwilling to say definitively that they have discovered plumes, they are relatively confident that they have, barring some unexpected alternate explanation for the Hubble’s findings.
The possible discovery is important for two reasons.
First, the likely confirmation of plumes also confirms the presence of a subsurface ocean hitherto only surmised by scientists.
Second, the likelihood that vents exist that reach all the way down to the subsurface ocean could make the planned Europa mission far less complicated. The multiple flyby element would be able to observe the plumes from closer range, sampling their composition, and perhaps getting a good idea of how wide the vents are and what is causing them. Then the lander element could touch down near one of the vents and study it from closer range. The possibility of inserting a small submersible through the vent to the subsurface ocean exists. Currently NASA's probe Juno is orbiting Jupiter but is not intended to study that planet's moons.
Europa is not the only ice world to have water plumes erupting from its surface. Enceladus, a moon of Saturn, iced bound like Europa, has been observed as having plumes erupting from a presumed subsurface ocean. The Cassini probe has already passed close to Enceladus, passing through one of these plumes.
In short, the ice moons of the outer planets have become increasingly exciting destinations for future space exploration.