Astronomers find first proof of tectonic activity on an exoplanet

March 08, 2021 | Updated 2:16 pm

Astronomers find first proof of tectonic activity on an exoplanet

Discovered by the National Aeronautics and Space Administration’s (NASA) TESS mission in 2018, planet LHS 3844b is the first planet outside of our Solar System where scientists think they might have found traces of tectonic activity.

As per astronomers, the evidence is based off advanced simulations and on the observations of the rocky planet, which is moderately bigger than Earth. Moreover, this particular research also indicates that that the LHS 3844b has no atmosphere.

This leaves half of the exoplanet permanently exposed to its sun, which could mean the surface temperature might go up to roughly 800 degrees Celsius (1,472 degrees Fahrenheit) during the ‘daytime’ side. Meanwhile, on the ‘night-time’ side, the temperature might be around minus 250 degrees Celsius (minus 418 degrees Fahrenheit).

“We thought that this severe temperature contrast might affect material flow in the planet’s interior,” astronomer Tobias Meier, from the University of Bern in Switzerland said.

On the basis of the phase curve observations of the LHS 3844b’s possible temperatures and brightness, and computer models simulating various possible tectonic materials and heat sources, Tobias and his fellow astronomers suspect a hemisphere-scale flow of subsurface material is taking place.

Most of the simulations the scientists conducted showed a upwards flow on one side of the exoplanet and a downwards flow on the other end. However, in some scenarios those readings were reversed – a groundbreaking discovery, and something which doesn’t match the tectonic movement on Earth.

“Based on what we are used to from Earth, you would expect the material on the hot dayside to be lighter and therefore flow upwards and vice versa”, says geophysicist Dan Bower, from the University of Bern.

“On whichever side of the planet the material flows upwards, one would expect a large amount of volcanism on that particular side,” says Bower.

On the back of this, astronomers have put forward the idea that planet LHS 3844b could actually have one hemisphere completely covered in volcanoes, while the other side of the planet shows hardly any volcanic activity – due to the intense temperature contrast on the planet.

With more powerful space telescopes becoming available and our understanding of exoplanets develops, further observations and research should confirm what’s actually taking place across the surface of LHS 3844b.

“Our simulations show how such patterns could manifest, but it would require more detailed observations to verify,” says Meier.

“For example, with a higher-resolution map of surface temperature that could point to enhanced outgassing from volcanism, or detection of volcanic gases. This is something we hope future research will help us to understand.”

The research work was published in the Astrophysical Journal Letters.