You may not be so 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 it may have evidence of tectonic activity.
This proof is a set of advanced simulations based on observations of the rocky planet, which is slightly larger than Earth. Important for this special research paper, it does not seem that the exoplanet has an atmosphere.
This leaves half of the LHS 3844b permanently exposed to the sun and could 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) in “Night” – part of time.
“We thought that this severe temperature contrast could affect the flow of materials 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 believe that a hemispheric flow of underground material occurs.
Most simulations performed by 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 discovery and one that does not match the tectonic movement on Earth.
“Based on what we are used to on Earth, you would expect hot day material to be lighter and therefore flow upside down and vice versa,” says geophysicist Dan Bower of the University of Bern.
The basic reason is the change in the temperature of the mantle material as it moves, with the colder rock stiffening and becoming less mobile, and the warmer rock becoming much more liquid as it heats up. Scientists say that changing the surface and the material could lead to quite incredible tectonic activity.
“On any side of the planet the material flows upwards, we would expect a large amount of volcanism on that particular side,” says Bower.
As a result, scientists suggest that LHS 3844b may have an entire hemisphere covered by volcanoes, while the other side has almost no volcanic activity – all due to the intense temperature contrast around the planet.
The type of spill that would cause these volcanoes matches 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 is different from anything in our solar system.
As more powerful space telescopes come online and our understanding of exoplanets improves, further observations and research should help confirm what is happening on the surface of LHS 3844b – and whether it is really covered in half volcanoes.
“Our simulations show how such models might manifest, but would require more detailed observations to verify,” says Meier.
“For example, with a higher-resolution map of the surface temperature that could indicate an increased release from volcanism or the detection of volcanic gases. We hope that future research will help us understand.”
The research was published in Astrophysical Journal Letters.