STANFORD, Calif. — Extraterrestrial life may be much closer to Earth than we think! A new study exploring the icy shell of Europa, one of Jupiter’s largest moons, reveals that the frigid satellite shares striking similarities with Greenland, home to its own unique aquatic life.
Stanford researchers believe that life could have evolved in the moon’s shallow pockets of water near the surface. The results come from an analysis of symmetrical landforms called double ridges. They stretch for hundreds of kilometers across the surface of Europa, flanking a shallow trough.
Ice-penetrating radar observations have captured the formation of the same type of geometric features in northwest Greenland. This is compelling evidence of potentially habitable environments outside of the Jovian satellite.
“Because it’s closer to the surface, where you get interesting chemicals from space, other moons and volcanoes on Io, it’s possible that life will have a hit if there are pockets of water in the shell,” says lead author Professor Dustin Schroeder in a scholarly outing. “If the mechanism we see in Greenland is the way these things happen on Europa, that suggests there’s water everywhere.”
Find aliens by accident?
Curiously, the study authors weren’t actually looking for signs of life near Jupiter. Professor Schroeder is an expert on global warming, rather than aliens.
“We were working on something totally different related to climate change and its impact on the surface of Greenland when we saw these tiny double ridges – and we could see the ridges change from ‘unformed’ to ‘formed'”, explains Schroeder. .
After further examination, they identified a miniature version of Europe’s most prominent features – which is mostly flat. Professor Schroeder described them as “dramatic indentations”, reaching nearly 1,000 feet and separated by valleys about half a mile wide.
The Galileo spacecraft first photographed the formations in the 1990s. However, the explanation for their formation has remained a mystery – until now. The study in Nature Communication used data collected from 2015 to 2017 by NASA’s Operation IceBridge which monitors Earth’s polar ice.
It revealed that Greenland’s Double Ridge formed when ice fractured around a pocket of pressurized water that was refreezing inside. This caused two peaks to rise in the separate shape.
“In Greenland, this double ridge formed where water from surface lakes and streams frequently flows to the surface and freezes again,” says study lead author Riley Culberg. , a doctoral student in electrical engineering at Stanford.
“One way that similar shallow pockets of water could form on Europa could be that water from the subterranean ocean is forced into the ice shell by fractures – and this would suggest that there could be an amount reasonable exchanges inside the ice shell.”
An alien world like Greenland?
Rather than behaving like an inert block of ice, the moon’s shell appears to undergo a variety of geological and hydrological processes. The theory is supported by this study and others – including evidence of water plumes erupting at the surface.
A dynamic shell of ice, about 60 miles thick, could support habitability because it facilitates the exchange between the subterranean ocean and nutrients from nearby celestial bodies that accumulate on the surface.
“People have been studying these double ridges for over 20 years now, but this is the first time we’ve been able to observe something similar on Earth and see nature working its magic,” says the study’s co-author. Gregor Steinbrügge, a planetary scientist. at NASA’s Jet Propulsion Laboratory (JPL). “We are taking a much bigger step in the direction of understanding the processes that really dominate the physics and dynamics of the ice shell of Europa.”
The moon is home to a salty ocean deep beneath the ice, which has long captured the imagination of astronomers searching for extraterrestrial life.
“The mechanism we propose in this paper would have been almost too bold and complicated to propose without seeing it happen in Greenland,” adds Schroeder.
The results give researchers a unique radar signature to quickly detect double-ridge formations, which the scientists plan to use in future explorations of Europa from space.
“We’re another hypothesis on top of many – we just have the advantage that our hypothesis has a few observations of a similar feature forming on Earth to back it up,” Culberg says. “It opens up all these new possibilities for a very exciting discovery.”
Could UV light reveal life on Jupiter’s moon?
Millions of ancient microbes have been discovered 3,000 meters deep in Greenland’s glaciers, suggesting resistant species may be living in ice elsewhere in the solar system. This ice may be as fertile as the Earth’s oceans. Scientists have even found bacteria buried deep under the Antarctic ice sheet.
Scientists have long been intrigued by the possibility of finding extraterrestrial life forms in ice-covered worlds far from Earth, particularly on Europa. Europe’s ice surface is streaked with reddish-brown cracks, likely caused by microorganisms suspended in the ice.
Minerals from the rocky interior seep through cracks in the ice, being blasted by the Sun’s UV rays, creating the glowing surface of Europa. This same UV radiation can break up water molecules, allowing oxygen to flow back into the ocean. These are exactly the kinds of ingredients that life needs to get started in an aquatic environment.
South West News Service writer Mark Waghorn contributed to this report.