Dunes to Io, the terrible volcanic moon of Jupiter!

Everyone who has seen the movie as a teenager 2010: Odyssey dosadapted from Arthur Clarke’s novel of the same name, they are certainly fascinated by the idea of ​​exploring Io, the volcanic, and Europe, the ice, around Jupiter. Undoubtedly, this is even more true for those who are passionate about volcanology, oceanography and exobiology.

Before homework Suc i Junethe mission Galileo in orbit around Jupiter had transmitted fascinating images of these two Medici moons. Planetary scientists are still busy analyzing data on these two worlds, using the knowledge learned in geology with our Blue Planet. They have long encountered an enigma about Galileo’s images of the surface of Io. They reveal dune-shaped structures that, if good, are still being discussed, have nothing to envy to the terrestrial and even Martian dunes.

However, those who have studied either geology or more generally planetology, for example with the famous works Earth by Frank Press and Raymond Siever i Fundamental planetary science: physics, chemistry and habitability by Imke de Pater and Jack J. Lissauer, know that dunes form and evolve with sand grain transport processes. sand for salting with winds. Problems, Io, with his short stature and weakness gravityhas atmosphere very thin with a pressure of only one billion birthsatmosphere earthly. It is about 120 kilometers thick and consists mainly of carbon dioxide. suffers (NA2) leaving the attraction of Io, but constantly renewed by the volcanic eruptions dantesques of the small moon of Jupiter.

It was impossible to have strong enough winds in this atmosphere to account for the potential dune fields observed, which had led to the rejection of the dune hypothesis.

Wind transport with sublimated sulfur dioxide waves

A team of American planetary scientists, however, believes they have found the key to the puzzle, as they explain. via a post to NaturaComunicaciones. It is based on analysis of images of the surface of the Io, taken during the 14 years of the Galileo mission.

Our studies indicate the possibility of Io being a new “dune world” said the first author of the paper, George McDonald, a postdoctoral researcher in the Department of Earth and Planetary Sciences at Rutgers University in the United States, who added in a statement from the university: we have proposed, and tested quantitatively, a mechanism by which grains of sand can move and eventually form dunes. This work tells us so the environments in which dunes can be found are considerably more varied than the typical desert landscapes and non-stop in certain parts of the Earth or on the fictional planet Arrakis in “Dunes “.

Io is very volcanicits surface appears as a mixture of streams of to wash solidified by color dark, currents and regions covered with a special “frost”, that is, solidified sulfur dioxide.

According to the calculations of the researchers, these regions would sometimes be heated from below by the installation of currents of magma. Sulfur dioxide would then sublimate producing in turn dense fluxes from the surface gas behaving as well as winds stronger than those that can be born in the atmosphere of Io.

Mathematical models developed on Earth that take into account the sizes and ripples of dune fields from the equations of transporting grains of different sizes and densities under the action of the flow of a fluid (especially for wind transportation) can then be moved to the case of these OS streams2. Sand grains resulting from altered lava flows and sublimated sulfur dioxide streams are then able to explain the characteristics of dune field-like structures, which proves the hypothesis that they are.

Io is the closest to Jupiter’s largest moons and the most volcanic world in our Solar System, with more than 300 active volcanoes, thanks to its proximity to Jupiter’s huge gravitational pull. Explanations by Brian Cox. For a fairly accurate French translation, click on the white rectangle at the bottom right. English subtitles should then appear. Then click the female to the right of the rectangle, then “Subtitles” and finally “Automatically translate.” Choose “French”. © BBC Earth

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