Studies have just come up with a reason why the top icy layer of Jupiter’s moon, Europa, spins differently than what’s under it. The upcoming NASA mission called Europa Clipper will get an even closer look.
NASA researchers have strong evidence that there is a large and salty ocean hidden underneath the icy outer shell of Jupiter’s moon, Europa. New computers calculations suggest that this water may be making the iceshell spin faster or slower at different times.
Scientists have figured out that Europa’s icy outer shell is not attached to its interior and rotates differently from its ocean and rocky middle below. The newest research shows that the water currents on Europa could be impacting how the ice moves around.
Scientists want to understand how things on Europa’s surface like cracks and ridges are formed. To try to figure this out, they measured the push and pull of the ocean under the ice layer—known as drag—and think that it could be part of what causes these features. Over time, the icy shell is moved around by strong waves and currents, stretching and collapsing in some places.
Scientists at the University of Oxford, NASA’s Jet Propulsion Laboratory and other places have done experiments and looked at data models to learn that heating and cooling of Europa’s ocean might cause currents. This research was just published in JGR: Planets. The new study says something else: it suggests there is a link between what happens in the ocean and how quickly Europa’s icy shell spins. This hasn’t been known before.
NASA’s upcoming Europa Clipper mission could measure how fast Europa (an icy moon) is spinning. By comparing images from the past taken by Galileo and Voyager with the new ones taken by the Europa Clipper, scientists will be able to see if anything on the surface of this icy moon has changed.
For a long time, scientists have been arguing about whether the icy shell around Europa is turning faster than what is underneath. But instead of connecting it to the motion of the ocean within it, experts think that this has something to do with Jupiter. They believe that when Jupiter’s powerful gravity exerts its pull on Europa, its forces are also changing the way the moon’s outer layer moves and spins a bit faster.
The project scientist from JPL (Robert Pappalardo) said that it was a very shocking discovery for him that what goes on in the ocean’s circulation could affect the icy shell surrounding Europa. Geologists didn’t think this was something possible, but it turns out it might explain all the cracks and ridges found on Europa’s surface.
The Europa Clipper is a spacecraft that is almost finished being built and tested at JPL. It will launch in 2024 and get to Jupiter by 2030. Makers want it to fly past the moon around 50 times while it gathers data about Europa, which has an ocean deep inside of it. They are looking for signs that life could survive on Europa with its environment and conditions.
Uncovering Europa’s Mysterious Ocean World
NASA scientists used supercomputers to find out how the water in Europa’s deep ocean moves around. They also looked at how heat and cold temperatures affect the circulation of Europa’s ocean.
Scientists think that hot water rises to the top of Europa’s ocean because of heating inside its rocky core caused by radioactive material and things like tides. It is similar to when you heat up a pot of water on a stove – it gets warm, bubbles and floats up.
At first, the water moved mostly up and down, but since the moon rotates, the water was pushed in different directions – east-west then west-east. The researchers studied this movement of water and found that it can cause ice on top to spin faster or slower. This could change over time, speeding up or slowing down the rotation of this icy shell.
This work could help us figure out how the spinning of different ‘ocean worlds’ like Europa has changed over time. This knowledge might also shed light on their geological histories and what’s happening inside them.
Researchers from the journal JGR: Planets published a paper on February 19th, 2023 called “Turbulent Drag at the Ice-Ocean Interface of Europa in Simulations of Rotating Convection.” In this paper they looked into how the spinning ice around Jupiter’s moon, Europa, affects its ocean. This research suggests that the way that ice is spinning could explain why some parts of Europa’s ocean move faster than other parts.
Reference: “Turbulent Drag at the Ice-Ocean Interface of Europa in Simulations of Rotating Convection: Implications for Nonsynchronous Rotation of the Ice Shell” by H. C. F. C. Hay, I. Fenty, R. T. Pappalardo and Y. Nakayama, 19 February 2023, JGR: Planets.
DOI: 10.1029/2022JE007648
Uncovering the Secrets of Europa
The Europa Clipper mission is aiming to figure out if life can exist on Jupiter’s moon, Europa. To do this, the mission focuses on three areas: examining the ice shell covering Europa and checking out the ocean that lives underneath it; discovering what these two things are made of; and finding out about Europa’s geology. In short, this research helps scientists learn more about worlds that could hold living things outside our planet Earth.
Caltech in Pasadena, California is responsible for the mission. Jet Propulsion Laboratory (JPL) and Johns Hopkins Applied Physics Laboratory (APL) both worked together with NASA’s Science Mission Directorate from Washington to design and develop the main spacecraft body. The Europa Clipper project is supervised by the Planetary Missions Program Office of NASA’s Marshall Space Flight Center in Huntsville, Alabama.
