Images captured by the Hubble Telescope have previously suggested the presence of ocean plumes ejected through tissues in the icy crust of Jupiter's moon. If plumes are indeed spewing vapor from Europa's ocean or subsurface lakes, Europa Clipper could sample the frozen liquid and dust particles.
Researchers are already working on missions to do just that. They found that Galileo had flown about 250 miles (400 kilometers) above the surface of Europa on December 16, 1997.
Scientists state Europa is a significant exploration destination since it may comprise the 3 components understood to be needed for life: liquid water; chemistry essential for life, such as hydrogen, carbon, oxygen, potassium, phosphorous, and sulfur; and vitality.
Near Enceladus' south pole, more than 100 individual geysers continuously blast water ice, organic molecules and other material far out into space - so far that this plume stuff forms Saturn's E ring.
Jia hopes this paper will inspire fellow researchers to keep looking at Europa's plumes. So they simulated the observations such a spacecraft would make if it flew through a plume of the size and density spotted by Hubble.
If it finds a plume, Clipper's instruments will be able measure its chemical composition, said Elizabeth Turtle, a planetary scientist at the Johns Hopkins Applied Physics Laboratory and one of the primary researchers involved with the mission. They found their simulation matched closely with the data from Galileo, giving them confidence to confirm that these magnetic signatures were caused by water escaping Europa's ice shell. Between 1995 and 2003, the nuclear-powered orbiter trained a suite of sophisticated instruments on Jupiter's turbulent atmosphere and its many moons, focusing on the four large Galilean satellites - volcanic Io and the icy worlds Europa, Callisto and Ganymede.
At the time of the 1997 flyby, about 124 miles (200 km) above Europa's surface, Galileo scientists didn't suspect the spacecraft might be grazing a plume erupting from the icy moon. And these lines of evidence are independent of those gathered by Hubble.
Jia said it was Melissa McGrath of the SETI Institute that inspired his team to dive back into the Galileo data.
The space agency is priming two probes, including one that will land on its surface, to explore the distant moon in detail within the next decade, the agency says. And as it turns out, Galileo passed right over a plume - but scientists at the time didn't know to look for it. "And I don't think those were available back 20 years ago". Now, a new study in Nature Astronomy not only proves they were right, but also confirms that it does something more awesome than they could have imagined: it shoots up out of the crust in big, handsome plumes.
However, we will have to wait a little longer before we get the confirmation on the water plume on Europa as the NASA's Europa Clipper and the ESA's JUICE will approach the icy moon of Jupiter sometime between late 2020 and early 2030.
The Europa Clipper mission is expected to shed more light on the elusive moon with rapid, low-altitude flybys from its orbit.
"These plumes, if they do indeed exist, may provide another way to sample Europa's subsurface".