Europa, a cold satellite of Jupiter only slightly smaller than our Moon, is currently one of the most promising places to look for extraterrestrial life in the Solar System. This world seems to hide an underground ocean, under an ice crust, that stores much more water than there is in the whole Earth. In addition, there has been detected the presence of organic molecules and interesting “geysers”, which expel water from the oceans into space, reasons why NASA prepares the launch of the mission “Europa Clipper”, from 2022. The objective will not be to detect living beings (because doing so would probably require landing there and piercing the ice), but to find out if this moon could harbor life, at least as we know it.
It is believed that the Europa moon hides an ocean with hydrothermal activity under an ice crust traversed by “geysers” – NASA
But in Europe there is a serious problem to detect the possible traces of living beings, the organic molecules: the incessant bombardment of radiation coming from Jupiter. This gaseous gas planet is a large dynamo surrounded by a magnetic field: it acts as a “cage” for charged particles and creates a powerful radiation belt, much larger than that of Van Allen, on Earth, which bombards high particles. energy the surface of Europe and that degrade the possible organic vestiges. However, a study just published in Nature Astronomy has revealed that, at most, only 20 centimeters from the icy surface of Europa, ice is capable of absorbing Jupiter’s radiation. For that reason, in theory it would be enough to scratch the surface of Europe to detect organic molecules and traces supposedly left by life forms.
The “geysers” of the surface of Europe release organic molecules from the ocean inside but these are degraded by the radiation of Jupiter – NASA / JPL-Caltech
“If we want to understand what is happening on the surface of Europe and how it is related to the ocean under it, we need to understand the radiation,” Tom Nordheim, co-author of the study and researcher at the Jet Propulsion Laboratory, said in a NASA statement. («JPL») in Pasadena (California).
To this end, researchers have used data from two ancient ships, Voyager 1, outside the Solar System, and Galileo, destroyed in Jupiter in 2003, to map the areas of Europe most affected by radiation. . In addition, they have done laboratory tests with amino acids, to try to find out how they affect the radiation of Europe to several organic molecules. Thus they have found out at what depth the bombardment of energetic particles is not capable of destroying the potential traces of life.