Jupiter moon Europa shows potential support for alien life, old data reveals
Image credit: reuters
Re-examination of old data from a flyover of Europa, one of the moons of Jupiter, has provided new evidence that it could be a leading candidate for life beyond Earth.
The Galileo spacecraft passed over Europa in 1997, where it detected a bend in the body’s magnetic field which is now believed to be evidence that a geyser gushed through its frozen crust from a subsurface ocean.
Previous ultraviolet images from Nasa’s Hubble Space Telescope in 2012 suggested the presence of plumes, but this new analysis used data collected much closer to the source and is considered strong, corroborating support for plumes.
“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,” said Robert Pappalardo, Europa Clipper project scientist at Nasa’s Jet Propulsion Laboratory.
Europa Clipper is a new satellite expected to launch between 2022-2025 that will perform follow-up studies to those made by Galileo during its eight years in Jupiter orbit.
Galileo was passing some 200km above Europa’s surface when it apparently flew through the plume.
“We know that Europa has a lot of the ingredients necessary for life, certainly for life as we know it. There’s water. There’s energy. There’s some amount of carbon material. But the habitability of Europa is one of the big questions that we want to understand,” said planetary scientist Elizabeth Turtle of Johns Hopkins University Applied Physics Laboratory.
“One of the really exciting things about detection of a plume is that that means there may be ways that the material from the ocean - which is likely the most habitable part of Europa because it’s warmer and it’s protected from the radiation environment by the ice shell - to come out above the ice shell. And that means we’d be able to sample it,” Turtle told a Nasa briefing.
Europa Clipper will sail close by the moon in rapid, low-altitude flybys. If plumes are indeed spewing vapour from Europa’s ocean or subsurface lakes, Europa Clipper could sample the frozen liquid and dust particles. The mission team is gearing up now to look at potential orbital paths and the new research will play into those discussions.
The findings support other evidence of plumes from Europa, whose ocean may contain twice the volume of all Earth’s oceans.
Europa is considered among the prime candidates for life in our solar system, but is not the only one. For example, Nasa’s Cassini spacecraft sampled plumes from Saturn’s ocean-bearing moon Enceladus that contained hydrogen from hydrothermal vents, an environment that may have given rise to life on Earth.
Slightly smaller than Earth’s moon, Europa’s ocean resides under an ice layer 15-25km thick, with an estimated depth of 60-150km.
Nasa’s Juno probe has been circling Jupiter since 2016 and its final act may be to be deorbited into the gas giant later this year, if Nasa decides to end the mission.
The probe began transmitting images of Jupiter’s Great Red Spot in July 2017 after coming closer to the anomaly than any previous probe.