Iron volcanoes on some asteroids may have ejected molten metal

The solar system is full of volcanoes – but scientists may have come to identify a type of volcanic activity entirely new.

This is the suggestion of a research conducted by two separate teams on metallic asteroids. Scientists have never really examined any of these objects, but a NASA spacecraft should arrive at Psyche, the largest of them, in 2026 if all goes well.

"This is not a shocking idea, but we had never thought of iron volcanism before, so it is something new and interesting to study," Jacob Abrahams, lead author of one of the new papers and PhD student in Planetary Science at the University of California at Santa Cruz, said in a statement.

Related: NASA unveils two new missions to study real strange asteroids

Here on earth, volcanoes erupt, or as scientists call it, the silicate crust. And scientists have found traces of cryovolcanisme on distant worlds in the outer solar system, where liquid water takes the place of lava. And now, scientists believe that in certain special circumstances, some metal asteroids have already seen molten iron volcanoes cool down.

Scientists believe that these asteroids are the remains of planetesimals, with large collisions stripping their rock layers and leaving only a molten metal core. Then this nucleus would solidify.

But now, two separate research teams modeling this cooling process have concluded that if the solidification process were to start off the outside of the asteroid, some of these bodies might have temporarily hosted liquid metal volcanoes on their metal surface.

It is possible that there were even different eruption styles for these metal volcanoes, depending on the precise composition of their molten lava. "If it's mainly pure iron, superficial low-viscosity rashes spread to thin leaves, so nothing looks like the thick, viscous lava you see on Hawaii, "Abrahams said in the statement." At the other extreme, if there are mixed light elements and gases that are growing rapidly, you could have explosive volcanism that could leave pits on the surface. "

It is far too cold in the asteroid belt for these volcanoes to be active today, and there is a good chance that the volcanoes have eroded over the course of the billions of years that followed. their eruption. But scientists hope to find evidence of this volcanic activity. The psyche mission of NASA is their best hope: it will target the asteroid of the same name, launched in 2022 and arrived at the strange world in 2026.

But scientists may not need to visit these metal worlds to understand their past, because the Earth is littered with metal meteorites originating in these metal asteroids. These meteorites could show signs of very rapid cooling or gas leakage.

The research of Abrahams and his colleagues has been accepted for publication in the journal Geophysical Research Letters; Johnson and his colleagues presented their research last month at the annual conference on lunar and planetary science in Texas.

Email Meghan Bartels to [email protected] or follow her @meghanbartels. follow us on Twitter @Spacedotcom and on Facebook.