Scientists say similarities between Greenland and Europa show Jupiter's moon might be able to sustain life.
The surface of Europa, some 390 million miles away, shows “striking double ridge features” that are symmetric on both sides, with a trough in the middle, says Stanford University geophysics professor Dustin Schroeder. His research group, which studies both Europa and Earth’s ice sheets using radar, discovered similar features on the surface of Greenland.
In Greenland, the ridges were formed by refrozen pockets of water, he says.
“If the same process covers the formation of the double ridges on Europa, then there would be pockets of water underneath these ridges all over Europa,” Schroeder says, “suggesting that water may be much more abundant in the middle of the ice shelf than we would have thought.”
Underneath Europa’s ice shell lies a global ocean, and evidence suggests it has more liquid water than the Earth. But the ocean is separated from the surface by the thick ice shell.
If combined with water, chemicals from space and nearby moons like Io could make Europa habitable. These chemicals reach the surface of the ice shell, which blocks the chemicals from reaching the liquid water below, Schroeder says.
“Forming these ridges brings water closer to the surface, and that increases the chance that you'll have an opportunity for exchange to get those chemicals into the water,” Schroeder says. “That’s hopeful news for that to be a potentially habitable piece of water.”
For Schroeder, the discovery was also a reminder of the joy and value of advising research groups: One of his postdoc researchers studying Europa gave a talk and showed parts of the moon that scientists can’t explain. The same day, a Ph.D. student researching the effects of warming events on the surface of Greenland was looking at radar data and saw the double ridges on the island. After spotting the commonality between Europa and Greenland, the team spent months trying to understand how the ridges formed in Greenland to help explain what was happening on Europa.
Schroeder’s work will continue with a new mission. He’s a science team member for the Europa Clipper, which NASA plans to launch in 2024. The motivation behind the mission is to understand whether Europa can sustain life.
The Europa Clipper mission included ice-penetrating radar, the same type of instrument used to study the features in Greenland.
“If similar water bodies do exist in the ice shell at Europa, we're bringing along the sort of instrument we want in order to see them in the same way we saw them here on Earth,” he says. “And that's for me the most exciting thing.”
This segment aired on April 20, 2022.