Based on what the scientists learned from exploring the water vapor plumes in Enceladus, one of Saturn's moons, and after conducting several studies in three dimensions, they concluded that this type of superficial movement also occurs in Europa.
'We needed to see whether there was anything in the data that could tell us whether or not there was a plume'.
The Galileo spacecraft of NASA traveled hundred twenty-five miles atop the Jupiter moon, Europa's surface on 19 December in the year 1997. The simulated results displayed how the magnetic field interacted with a plume erupting from Europa and backed the observations noted in the Galileo data.
"One of the locations she [the researcher announcing Hubble observations] mentioned rang a bell".
That's when the University of Michigan's Xianzhe Jia and colleagues chose to revisit those archival data and see what kinds of nuggets they could find.
"These results provide strong independent evidence of the presence of plumes at Europa", the study said.
The tallest of the plumes was so powerful that it extended 120 miles above the moon's surface; Old Faithful, the famous geyser at Yellowstone, reaches 184 feet.
Europa's frozen surface has always been thought to cover a salty ocean about twice the size of our planet's. The spacecraft's magnetometer, used to detect and measure magnetic field strength, and its plasma wave spectrometer, which measured charged particles in the environment, both recorded readings best explained by passage through a plume of water vapor, according to the new analysis. Gravity measurements will also help confirm the existence of Europa's subsurface ocean.A thermal instrument will survey Europa's frozen surface in search of recent eruptions of warmer water at or near the surface, while additional instruments will search for evidence of water and tiny particles in the moon's thin atmosphere. Material jetted from a plume and snowing back down onto the moon's surface would make landing sites in close proximity to the plume the most prized spots.
Life as we know it requires liquid water, so any discovery of liquid water in the solar system opens the potential for finding other life, though the expectation in our neighborhood is that it is microbial, not intelligent.
One ardent supporter of a mission to Europa, Texas Congressman John Culberson, broke the embargo on this news last week during a Congressional hearing on NASA's budget.
"When we look at those data carefully, what we found is there's some unusual magnetic signals in those data that have never been explained before", Jai says.
There has been much speculation about the possibility of life on Europa.
The lawmaker was in the middle of expounding on an annual preoccupation: Putting more money into a robotic space-exploration project expected to cost $8 billion or more by the time it launches sometime after 2022.
When Galileo orbited Jupiter between 1995 and 2003 it collected reams of data, including from 11 flybys of the moon Europa. Even if the water from Europa's icy seas comprises a massive number of additives, bringing the freezing temperatures lower than it's on Earth, it might still be warm enough to become liquid.
"If plumes exist, and we can directly sample what's coming from the interior of Europa, then we can more easily get at whether Europa has the ingredients for life", he added.
"That's the moment where we realized that we might have something in the old Galileo data that we never paid much attention to", Jia says. That's the big picture.