In their search for signs of habitability and biosignatures, scientists have drawn up a new more comprehensive map of the radiations bombarding Jupiter’s icy moon Europa and they understand better now where to look for answers and how deep they will have to drill.
The conclusion of the newest research on the subject is that radiation from Jupiter can destroy the molecules found on Europa’s surface. Any material that surfaces from Europa’s ocean will be affected by this radiation, which will destroy any biosignatures that could indicate the presence of life.
NASA’s Galileo mission launched in the 1990s brought strong evidence that underneath Europa’s icy shell there is a global ocean. Based on this crucial information, scientists have considered Europa one of the most promising places in our solar system to look for ingredients to support life. There’s even evidence that the salty water makes its way to the surface from the inside of the moon. This water brings with it material from the interior and the scientists want to study this material hoping to learn more about the possibility to inhabit Europa.
The problem is that the radiation coming from Jupiter bombards Europa’s surface and alters the material that comes from the interior. In this context, scientists don’t know whether the material they study represents the actual conditions in Europa’s ocean.
In a new scientific study, published in Nature Astronomy, lead author Tom Nordheim, a research scientist at NASA’s Jet Propulsion Laboratory, Pasadena, California, explains that in order to understand what happens at the surface of Europa, scientists have to understand radiation first. Researchers have to determine whether what comes up from the subsurface is what is actually in the ocean or it is remains of materials after having been radiated.
Nordheim and his team took a closer look at the electrons blasting the moon’s surface. They discovered that the radiation doses vary by location. The zones around the equator are highest in radiation, while at the poles they observed the lowest levels of radiation. The harsh radiation zones cover more than half of the moon.
With this information at hand scientists are now able to identify those regions that are least affected by radiation and this will be of crucial importance for the NASA future mission, Europa Clipper. There will be about 45 close flybys to orbit Jupiter and monitor its moon, Europa. The mission is planned to launch in 2022 and will investigate the composition of the moon’s surface, its ocean, and material that has been ejected from the surface with the help of cameras, spectrometers, plasma and radar instruments.
In his study, Nordheim determined that scientists need to dig or drill from 10 to 20 centimeters in the highest-radiation zones—down to less than 1 centimeter deep in regions of Europa at middle- and high-latitudes, in search for biosignatures. He came to this conclusion after tests run on amino acids, which are basic building blocks for proteins and among the simplest molecules that qualify as a potential biosignature.
Kevin Hand, co-author of the new research, says that the radiation coming from Jupiter leaves a fingerprint on Europa’s surface. If scientists know what the fingerprint looks like they will be able to better understand the nature of any organics and possible biosignatures that might be detected with future missions.
Europa Clipper’s mission is to look for potentially fresh material that hasn’t been altered by the radiation.
Jasmine holds a Master’s in Journalism from Ryerson University in Toronto and writes professionally in a broad variety of genres. She has worked as a senior manager in public relations and communications for major telecommunication companies, and is the former Deputy Director for Media Relations with the Modern Coalition. Jasmine writes primarily in our LGBTTQQIAAP and Science section.