According to a NASA study, Shallow Lakes in Jupiter’s Moon Europa’s Icy Crust Could Erupt.
Subsurface sources of water in our outer solar system are some of the most important targets in the search for life beyond Earth. For this reason, NASA is sending the Europa Clipper spacecraft to Jupiter's moon Europa.
According to new research, NASA's Europa Clipper can test that any plumes or volcanic activity on the surface of the Jovian moon are caused by shallow lakes in its ice crust.
However, scientists believe the ocean isn’t the only water on Europa. NASA believes salty liquid reservoirs may exist within the moon's icy shell, some near the surface and some several miles below.
The more scientists understand about the water that Europa may have, the more possible it is that they will know where to look for it when NASA sends Europa Clipper to conduct a detailed investigation in 2024.
The spacecraft will orbit Jupiter and utilize its suite of sophisticated equipment to collect science data as it flies by the moon about 50 times.
A key finding in new research published in "Planetary Science Journal" supports the long-held belief that water might erupt above the surface of Europa as plumes of vapor or as cryovolcanic activity.
The computer modeling in the paper goes further, showing that if eruptions occur on Europa, they are probably caused by shallow, wide lakes embedded in the ice, not the global ocean far below.
Elodie Lesage, Europa scientist at NASA and lead author of the research, said, “We demonstrated that plumes or cryolava flows could mean there are shallow liquid reservoirs below, which Europa Clipper would be able to detect.”
Different Depths, Different IceLesage's computer modeling gives a blueprint for what scientists could find inside the ice if they observe explosions at the surface.
According to her models, they likely would detect reservoirs quite near the surface, in the upper 2.5 to 5 miles (4 to 8 kilometers) of the crust, where the ice is most brittle and coldest. That’s because the subsurface ice there doesn’t allow for expansion.
As the pockets of water freeze and expand, they may break the surrounding ice and cause eruptions, similar to how a can of soda bursts in a freezer.
Also, pockets of water that do burst through would likely be wide and flat like pancakes.
Deeper reservoirs, with floors greater than 5 miles (8 kilometers) below the ice layer, would push against warmer ice around them as they expand.
That ice is soft enough to act as a cushion, absorbing pressure instead of exploding.
Instead of acting like a can of soda, these pockets of water would behave more like a liquid-filled balloon, where the balloon simply stretches as the liquid within it freezes and expands.
Sensing FirsthandThis research will be useful to scientists on the Europa Clipper mission when the spacecraft arrives at Europa in 2030.
One of the key instruments that will be used to look for water pockets in the ice is the radar instrument known as 'Radar for Europa Assessment and Sounding Ocean to Near-surface' (REASON).