The solar system is full of volcanoes – but scientists may have identified a completely new type of volcanic activity.
That is the suggestion of the investigation carried out by two separate teams that observe metal asteroids. Scientists have never seen one of these objects well, but a NASA spacecraft should reach Psyche, the biggest of them, in 2026 if all goes well.
"It's not a shocking idea, but we've never thought about iron volcanism before, so it's something new and interesting to investigate," Jacob Abrahams, lead author of one of the new articles and a doctorate in planetary science at the University. from california santa cruz, he said in a statement.
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Here in the earth, volcanoes erupt molten rock, or as scientists call it, silicate bark. And scientists have found traces of crovolcanism in distant worlds in the outer solar system, where liquid water takes the place of lava. And now, scientists think that in special circumstances, certain metal asteroids saw molten iron volcanoes when they cooled.
Scientists believe that these asteroids are the remains of planetesimals, with large collisions. stripping its rock layers And leaving only a molten, metallic core. Then, that nucleus would solidify.
But now, two independent research teams modeling the cooling process have come to the conclusion that if the solidification process started outside the asteroid, some of these bodies could have temporarily housed liquid metal volcanoes on their surface, exploding through a solid layer. metal.
It is possible that there were different styles of eruption for these metal volcanoes, depending on the precise composition of their molten lava. "If it's mostly pure iron, then you'd have eruptions of low viscosity surface fluxes that spread out thin sheets, so there's nothing like the thick, viscous lava flows you see in Hawaii"Abrahams said in the statement." At the other extreme, if there are mixed light elements and rapidly expanding gases, there could be an explosive volcanism that could leave wells on the surface. "
It is too cold in the asteroid belt for these volcanoes to be active today, and it is very likely that in the billions of years since their eruption, the volcanoes have eroded. But scientists hope, however, that they can detect evidence of such volcanic activity. NASA's psyche mission it is your best hope: it will point to the asteroid of the same name, it will launch in 2022 and it will arrive in the strange world in 2026.
But scientists may not need to visit these metallic worlds to understand their pasts, since the Earth is full of metal meteorites They originate in these metallic asteroids. These meteorites could show signs of very rapid cooling or of content of gas that flees.
The investigation of Abrahams and his colleague. has been accepted for publication in the Geophysical Research Letters; Johnson and his colleagues presented his research last month at the Annual Lunar and Planetary Science Conference in Texas.