You may not be as familiar with the planet LHS 3844b, but it now has its own distinction: it is the first planet outside our solar system where astronomers believe they could have evidence of tectonic activity.
This evidence is a set of advanced simulations based on observations of the rocky planet, which is slightly larger than Earth. It is important to note that this particular research does not appear to have an exoplanet atmosphere.
This leaves half of the LHS 3844b permanently exposed to its sun and can mean temperatures of up to about 800 degrees Celsius (1,472 degrees Fahrenheit) on the “daytime” side and about minus 250 degrees Celsius (minus 418 degrees Fahrenheit) at night-time ‘ side.
“We thought that this severe temperature contrast could affect the flow of material inside the planet,” says astronomer Tobias Meier of the University of Bern in Switzerland.
Based on observations of the phase curve of the planet’s brightness and possible temperatures, and computer models that simulate various possible tectonic materials and heat sources, Meier and colleagues think that a underground material flow on a hemispherical scale.
Most of the simulations performed by the researchers showed only an upward flow on one side of the planet and only a downward flow on the other, but in some scenarios it was reversed: a surprising finding that does not match the tectonic motion of the earth.
“According to what we are used to from Earth, the material of the hot day is expected to be lighter and therefore flow upwards and vice versa,” says geophysicist Dan Bower of the University of Bern.
The underlying reason is the temperature change of the mantle material as it moves, with a colder rock that strengthens and becomes less mobile, and a warmer rock that becomes much more liquid as it heats up. Scientists say that the displacement of the surface and material could lead to quite incredible tectonic activity.
“On either side of the planet the material flows upwards, one could expect a lot of volcanism on that particular side,” Bower says.
As a result, scientists suggest that LHS 3844b could have an entire hemisphere covered in volcanoes, while the other side has virtually no volcanic activity, all due to the intense temperature contrast around the planet.
The type of outcrop that these volcanoes would cause coincides with what we see on Earth, but only in specific places, such as Hawaii and Iceland. In more general terms, the tectonic motion suggested by these models bears no resemblance to anything in our solar system.
As the most powerful space telescopes go online and our understanding of exoplanets improves, more observations and research should help confirm what is happening on the surface of LHS 3844b, and whether it is really half covered in volcanoes.
“Our simulations show how these patterns might manifest, but would require more detailed observations to verify,” Meier says.
“For example, with a higher-resolution surface temperature map that could signal greater degassing of volcanism or the detection of volcanic gases. We hope future research will help us understand that.”
The research has been published in Letters from astrophysical journals.