A planned visit to the asteroid Psyche by the spacecraft can bring direct evidence.
The birth of the solar system meant a gradual growth of the planet's germs, but also its collisions. Some linked them to larger bodies, others were broken into pieces.
Among the ruins of devastating rain, we often find huge balls of liquid metal. These, according to a new study, have developed over time a solid bark that has been broken by iron volcanoes.
Research paper published by Geophysical Research Letters.
The rest of the planet that did not arise
The Asteroid Psyche is the last complete memorial to the devastating events of the early youth of the solar system.
This 230-kilometer piece of iron is the rest of the protoplanet – the ancient nucleus of about 1,000 emerging worlds.
When NASA announced a plan to send a space probe to Psyche in 2022, Jacob Abrahams and Francis Nimmo, a planetary scientist at the University of California, Santa Cruz, decided to review the development of metal asteroids.
In fact, any new findings could guide future Psyche research in areas that were not initially considered.
Bright one-mile balls
In their analysis, the researchers found that the nuclei of the planets hardened after more than 100 million years. This means that from the devastating collisions of the early development of the solar system, huge liquid iron liquid balls had to emerge.
Even the simple modeling of its cooling and solidification showed that these processes did not dispense with volcanic eruptions.
"Before, it never occurred to me, but it makes sense because you have less dense liquid under a much denser bark. In such an environment, the liquid is being pushed to penetrate the top," says Francis Nimmo, co-author of the research.
Thin paper lava flows?
The study suggests that shiny metal balls – originally broken nuclei in protoplanets – would cool and solidify very quickly in the cold of the cosmos.
"In some cases, they would stiffen from the middle, so volcanism would not occur, but in others, solidification would begin at the surface and move inward, so that a solid outer shell with liquid metal would be formed below," says Nimmo.
"If pure iron forms the melt, small viscous flows leach to the surface, flowing in the form of thin layers," continues Jacob Abrahams. "So they do not resemble the coarse streams of viscous lava that you can see in Hawaii."
Otherwise, volcanic activity occurred as long as the melt contained mixtures of lighter elements and gases that expanded rapidly when the pressure fell.
"The result would be an explosive volcanism that would leave a deep depression on the surface," says Abrahams.
The best evidence is … on Earth?
According to the authors of the study, the Psyche spacecraft may come across various evidences of an ancient volcanism. For example, variations in the color or composition of the surface, or volcanic structures like volcanoes.
Large volcanic cones – a typical surface manifestation of volcanic activity – but the study authors do not expect. Billions of years have passed since the expected volcanic activity in Psyche and similar bodies, so they seem to have separated long ago.
However, evidence of volcanic activity in metal asteroids may also bring in research for bodies that hit Earth.
"We know a wide range of metallic meteorites and, thanks to our research, we know exactly what to look for in them," says Francis Nimmo.