!We could well detect signs of life in the geysers of Enceladus
We know that geysers of icy particles, probably connected to the global ocean under the ice floe of Saturn's moon Enceladus, have already been able to be "sniffed" by the Cassini probe's instruments. A future mission with more efficient detectors could in principle highlight complex molecules of life, but are these molecules not destroyed into smaller, insignificant particles by collisions between icy particles? Exobiologists wanted to find out with experiments on Earth.
We expect a lot from the mission Europa Clipper which, by the 2030s, should teach us more about Europe , the icy moon of Jupiter, particularly regarding evidence of the presence of life forms in its ocean. But some people think that a mission to a destinationEncelade, another moon with aice floeoverall, but aroundSaturnthis time would be more promising. There are certainlygeysersas in the case of Europa whose chemical composition can be "sniffed", in search of organic molecules which could be biosignatures of life but, above all, the flux of cosmic rays around Enceladus is less deleterious for electronics than in the case of Europe. We could therefore more easily envisage a mission truly in orbit around Enceladus and possibly a lander responsible for taking samples to bring back to Earth.
However, in the case of the icy particle geysers of Enceladus discovered by the Cassini mission, a problem arises: #39;estimate of the speeds of these particles places them around 400m/s, which, during collisions between these particles, can lead to significant fragmentation of the organic molecules present in the ice. Let's imagine for example a bit ofDNAcompletely fragmented, we could still deduce that there are processes in Enceladus leading to DNA building blocks but not the presence of DNA itself.
beneath its icy surface, saturn's icy moon enceladus holds many surprises: a reservoir of liquid water, organic chemical compounds and hydrothermal vents. find out what you need to know about enceladus, an ocean world that may provide favorable conditions for life. to obtain a fairly accurate french translation, click on the white rectangle at the bottom right. english subtitles should then appear. then click on the nut to the right of the rectangle, then on “subtitles” and finally on “automatically translate”. choose “french”.
nasaResearchers from theUniversity of California San Diego wanted to find out for sure by reproducing collisions between particles in the laboratory of ice from the geysers of Enceladus. As they explain in an article published in The Proceedings of the National Academy of Sciences (PNAS< /span>), their conclusion is very encouraging. They were able to detect amino acidsdespite collisions at speeds of up to not 400 m/s but 4.2 km/s!
We can also think that this conclusion is valid for Europe and that;Europa Clipperwill be able to detect this type of molecules during itsflyovers moon which we know, thanks to Hubble observations, that it can also spit out icy particles. a>
In a press release, Robert Continetti, professor emeritus of chemistryand ofbiochemistry at UC San Diego and is one of the authors of the article published in PNAS, The implications this has for the detection of life elsewhere in the : “ explainsSolar system without missions to the surface of these oceanic moons are very interesting, but our work goes beyond biosignatures in ice grains. This also has implications for fundamental chemistry. We are excited to follow in the footsteps of Harold Urey and Stanley Miller, founding UC professors San Diego, studying the formation of the building blocks of life from chemical reactions activated by the impact of ice grains. ”.
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