Life can swarm a few inches below the frozen surface of Europa

Regarding extraterrestrial life, Europa does not seem to be a particularly attractive place, at least at first glance. The frozen moon of Jupiter looks like a small sterile world, too far from the Sun to attract attention. But modern science has discovered that under the icy surface of Europa, there is almost certainly an ocean of liquid water – an ocean of water supposed to be in direct contact with the nucleus of the satellite, this which could cause intriguing chemical reactions. We already know from the hot springs of the Earth that ecosystems can be formed without the energy of the sun, relying on the chemical and thermal energy of the depths of the ocean [19659004] Could this also be the case on Europa? suspects that plumes of water and gas could contain the biosignatures of life, but then again – as well as the surface of Europe itself. In a new study of this problem, the researchers explain that if these signatures exist, they may very well be close to the surface – they just need to survive the intense radiation of Jupiter, which can destroy or alter the materials transported to the surface. the surface.

"Our results also show that amino acids, although highly concentrated, would persist at detectable levels … over 10 million years at depths of 10 centimeters even in the most severe environments of the surface of Europe, "the researchers write. the paper, published today in Nature Astronomy.

Europa surface could accommodate signs of life. Image credits: NASA.

They published a new detailed map detailing this radiation. As scientists try to see which are the best places to search for life, this type of map can be extremely useful to decide where not to look. The author or T of Nordheim, a researcher at NASA's Jet Propulsion Laboratory in Pasadena, California, explains that understanding how radiation works on Europa is vital to this research . Extraterrestrial Life

"If we want to understand what is happening on the surface of Europa and how it relates to the ocean below, we must understand the radiation", said Nordheim. "When we look at the materials that come out of the basement, what are we looking at, does that tell us what's in the ocean, or is that what happened to the materials after that?" They were radiated? "

Nordheim and his colleagues found that the radiation-surviving amino acids could hide 10 cm below the surface, barely scratched – but at reduced concentrations. want to increase their chances of finding life, astronomers should go further from the equator of Europe, to its higher latitudes – where the moon is pointing away from Jupiter.In addition, they should look for the "young" ice, not exceeding 10 million years

Of course, all this is based on an enormous hypothesis: the idea that life on Europa exists – some thing that we have no information on and are only theorizing for the moment.But the study arrives Just in time, since NASA and ESA have plans to send research shuttles to Europa in the not-too-distant future: the early 2020s.

The Europa Mission NASA's Clipper will explore Europa's livability, and tell his sister, the Europa Lander, where to look for signs of life. Meanwhile JUICE (ICy moon Explorer of JUpiter) will carry out detailed investigations on Ganymede – another jovian moon similar to Europa – and will also investigate Europa.

These missions would both benefit from this radiation card. Radiation bombarding the surface of Europe leaves a fingerprint, "said Kevin Hand, co-author of the new research and project project for the potential mission of Europa Lander. "If we know what this fingerprint looks like, we can better understand the nature of all organic and possible biosignatures that could be detected with future missions, be they spacecraft flying or landing on Europa."

et al. Preservation of potential biosignatures in the shallow subsurface of Europa, Nature Astronomy (2018). DOI: 10.1038 / s41550-018-0499-8

Did you like this article? Join more than 40,000 subscribers to the ZME Science newsletter. Subscribe now!