Greenland climate study may help identify life on Jupiter’s moon

Scientists have high hopes of finding life on Jupiter’s moon Europa, but they have been stymied by the thickness of its ice sheets. But a study of Greenland’s ice sheet indicates that water pockets on Europa may come closer to the surface than previously believed.

Ever since pictures of the ice surface of Jupiter’s moon Europa were taken by the Voyager 2 probe in 1979 and then the Galileo probe in the 1990s, it has been considered one of the most likely locations for us to find alien life forms within our Solar System. Under the ice surface is a huge salt water ocean which might harbour life.

The chances of finding life on Europa are so promising that NASA has funded a mission to the moon with the Europa Clipper probe. It will be launched in 2024 and is expected to enter into orbit around the moon in 2030. The plan is for the probe to use radar equipment that can see through the ice, but physicists could be frustrated by the thickness of that ice. If greater than 20-30km thick, the ice sheet could prove impenetrable.

But now scientists from Stanford University have good news. The water might be much closer to the surface than was previously believed.

The discovery came by accident. The scientists had set out to study how the expansion and retreat of Greenland’s ice sheet influences rising sea levels as part of climate change on Earth. But during a chance attendance at a presentation about the surface of Europa they realised that the formations on Jupiter’s moon were surprisingly similar to surfaces they had found in Greenland, particularly a double-ridge ice formation like a canal with ridges on each side.

By analysing data from NASA’s radar study of Earth’s polar ice caps (‘Operation IceBridge’), the scientists could observe how one double-ridge ice formation in north-western Greenland had been formed. They could see that ice had cracked around a pocket of compressed water that was re-freezing in the Greenland ice sheet, making two ridges rise up. According to one of the scientists, Riley Culberg, this same process could take place on Europa.

“In Greenland, the double-ridge ice formation developed in a place where water from surface lakes and streams often flows into the near surface to refreeze,” he says. “Similar surface water pockets could form on Europa via water from the ocean under the surface forced up into the ice sheet via cracks.”

Europa is covered in double-ridge ice formations that have been a mystery to astrophysicists. If they are indeed formed by the Greenland method, it means water is far closer to the surface, and so easier to study by means of radar.