Volcanoes are everywhere in our Solar System. But the latest study suggests that volcanoes full of liquid iron may have erupted on metal asteroids.
Scientists at UC Santa Cruz have conducted a new study about how metallic asteroids formed. It’s all part of NASA’s plans to send a probe to Psyche, the largest metallic asteroid in the solar system.
So, these metallic rocks originated as blobs of molten iron floating in space. Thanks to the incredibly cold temperatures of space, the metal cooled and solidified. So, during this time, volcanoes could have erupted through a solid iron crust onto the surface of the asteroid.
“It’s not a shocking idea, but we’d just never thought about iron volcanism before, so it’s something new and interesting to investigate,” Jacob Abrahams, lead author on one of the new papers and a doctoral student in planetary science at the University of California Santa Cruz, said in a statement.
Researchers have published their work in the journal Geophysical Research Letters.
Francis Nimmo, professor of Earth and planetary sciences, said he was interested in the composition of metallic asteroids indicated by analyses of iron meteorites. So he had graduate student Jacob Abrahams work on some simple models of how the asteroids cooled and solidified.
“One day he turned to me and said, ‘I think these things are going to erupt,'” Nimmo said. “I’d never thought about it before, but it makes sense because you have a buoyant liquid beneath a dense crust, so the liquid wants to come up to the top.”
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Scientists find it hard to understand what the volcanoes would look. But Abrahams said it all depends on the composition of the melt.
“If it’s mostly pure iron, then you would have eruptions of low-viscosity surface flows spreading out in thin sheets, so nothing like the thick, viscous lava flows you see on Hawaii,” he said in the statement. “At the other extreme, if there are light elements mixed in and gases that expand rapidly, you could have explosive volcanism that might leave pits in the surface.”
Unfortunately, metallic asteroids have solidified fairly quickly after their formation. So, time (billions of years) has degraded any surface features of volcanism. “It’s not clear what they might look like now,” Abrahams said.
The best opportunity to find evidence of ferrovolcanism might actually come from studying iron meteorites already in collections on Earth.
“There are lots of these metallic meteorites, and now that we know what we’re looking for, we might find evidence of volcanism in them,” Nimmo said. “If material got erupted onto the surface, it would cool very fast, which would be reflected in the composition of the meteorite. And it might have holes in it left by escaping gas.”
NASA plans to launch Psyche mission in 2022, therefore, reaching the strange world in 2026.
Thumbnail image: An artistic illustration of the metallic asteroid Psyche during its hypothesized volcanic phase. Credit: Elena Hartley