The highest CO2 levels are found in a 1,800 square kilometer region called Tara Regio, where table salt has also been found.
Europa, one of Jupiter’s moons, is one of the main research objects in the search for habitable places in the solar system. Scientists believe there may be one in its vast ocean the chemical balance necessary for the existence of life. However, to assess this potential habitability, it is necessary to better understand the composition beneath its frozen surface and the possible presence of essential elements such as carbon.
Solid carbon dioxide (CO2) in the form of has already been detected in previous work Dry ice on the surface of Europe. However, it has not yet been possible to clarify where it comes from: whether the CO2 comes from the subsurface ocean, whether it reached the moon’s surface through meteorite impacts, or whether it was created on the surface through interactions with the moon’s magnetosphere. Jupiter (the region surrounding the planet where physical phenomena are dominated by its magnetic field).
This Thursday, two independent studies published in the journal Science, based on recent analyzes of frozen CO2 in Europe, suggest that this element could come from a abundant source of carbon in this star’s ocean. Europe is believed to have done this There is a large amount of salt water beneath its surface, under its ice crust. In the first study, researchers at Cornell University analyzed CO2 on the surface of Europa using near-infrared (NIR) spectroscopy data collected by the James Webb Space Telescope (JWST).
Based on these observations, they were able to map the distribution of carbon dioxide and found that The highest CO2 content is found in the Tara Region. “Tara Regio is a large region of geologically altered terrain on the surface of Europe, where exchanges between the subsurface and surface environments may have occurred,” explains Samantha K. Trumbo, a researcher at Cornell University (USA). “In fact, we know that its composition is different from the rest of the terrain because the Hubble Space Telescope discovered salt (NaCl) in it, which likely comes from the ocean within.”
Specifically, it is a region of approx 1,800 square kilometers, dominated by terrain that corresponds to what researchers call “chaos zones,” geologically altered areas that have reemerged from the interior. According to the authors, the amounts of CO2 identified in this region – one of the youngest on the surface of Europe – indicate that it must come from an internal source. This means that CO2 was formed in the European ocean and brought to the surface at a geologically younger period. However, the authors state that the formation of CO2 at the surface from organic compounds or carbonates from the ocean cannot be completely ruled out.
CO2 and other compounds
Determining the origin of this CO2 could be key to defining the chemistry of this inner ocean. In the second of the papers published in Science, Gerónimo Villanueva and his colleagues from the NASA Goddard Space Flight Center They also concluded that carbon dioxide is concentrated in the same region of the Tara Regio and agree that the carbon on the moon’s surface comes from its interior. In addition, they discovered that the CO2 on Europa’s surface is mixed with other compounds. Likewise, in their analysis, they measured the carbon-12 and carbon-13 isotope ratio of the ice, but were unable to distinguish between an abiotic (non-living) or biogenic source.
On the other hand, Villanueva and his team were looking for plumes of volatile material that had passed through the moon’s icy crust, as previous studies had found evidence of them. However, the authors did not detect these types of materials in the JWST observations. Because of this, they suspect that it is rare or that it does not contain the elements on which they focused their search.
In any case, the results of both studies complement each other and support the hypothesis that the ocean beneath Europa’s surface contains abundant carbon. “The geographical connection between Europe’s surface CO2 and the Tara Regio, a geologically young and altered area, suggests that the CO2 (or at least the carbon in CO2) comes from the inner ocean,” concludes Trumbo. “Further evidence that we can learn a lot about the chemistry of this ocean by studying the surface composition of these geological regions, and it shows that there is more at the surface than just salt coming from the ocean.”