For the first time, researchers from the University of Bern in Switzerland have found evidence of tectonic activity on a planet outside of our Solar System.
The exoplanet, called LHS 3844b, has a rocky surface and is slightly larger than Earth. Unlike Earth, however, it doesn't appear to have an atmosphere. Moreover, one-half of the planet is permanently exposed to the sun, meaning temperatures there can reach 800 degrees Celcius, whereas, on the other, non-sun-exposed side, temperatures are around -250 degrees Celsius.
The researchers suspected that this unusual contrast in temperature might impact material flow at the planet's interior. As such, they examined phase curve observations of the planet's brightness and possible temperatures, as well as computer models that simulated various tectonic materials and heat sources. In doing so, they found evidence of hemisphere-scale flow of subsurface material.
The majority of simulations created by the team found an upwards flow on one side of the planet, and a downwards flow on the other in relation to its temperature polarities. In others, however, these flows were reversed, something that was surprising as it is different from what occurs on Earth.
This dualism on the planet between upwards and downwards flow, say the researchers, could mean that one hemisphere is covered in volcanoes, while the other has hardly any. While the activity seen on the exoplanet matches activity seen in specific places on Earth, such as in Hawaii and Iceland, they say it is different from anything else previously seen in our solar system.
"Our simulations show how such patterns could manifest, but it would require more detailed observations to verify," says Tobias Meier, one of the authors of the study. "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."