Exoplanet: Back in 2018, US space agency NASA’s Transiting Exoplanet Survey Satellite (TESS) had discovered an exoplanet, which they named LHS 3844b. Since then, the exoplanet has been studied with much interest by astronomers. Now, a study by Switzerland’s University of Bern has found, based on the data TESS collected, that one side of LHS 3844b could be witnessing tectonic activity, causing volcanoes to erupt there and light up the night sky. The revelation is important because according to the University, scientists have not yet found any evidence of global tectonic activity on planets that are not a part of our solar system, and this could change that.
LHS 3844b is locked to its Sun in a manner that only one of its sides is constantly facing the host star. Consequently, the side facing its host star witnesses temperatures up to 770 degrees Celsius, while the side away from it has temperatures as low as -250 degrees Celsius, and it is located 45 light-years from Earth, the University said. It is slightly bigger than the Earth, while its host is a red dwarf star, a fifth of our Sun in size. The team’s research has been published in Astrophysical Journal Letters, in which the scientists state that they believe the vast temperature differential on the planet could be affecting the movement of material in the interior of the planet.
The team then ran simulations to understand whether this was the case, and in these simulations, they used varying strengths of material, along with different sources of internal heating. In most simulations, the team found that one side of the planet had only upwards flow of material, while the other side only had downwards flow, indicating that the material flowed from one hemisphere to the other, study lead author Dr Tobias Meier said. Interestingly, this direction of flow of material between hemispheres was not always the same.
On this, study co-author Dr Dan Browner said that they had expected the material on the hot side of the planet to be lighter and hence flow upwards, with the opposite effect taking place on the dark side. This expectation had been based on what happens on the Earth. However, he said that the simulations that show otherwise are because of the change in viscosity due to the temperature. The cold material has become stiffer and is resistant to bending, breaking or subducting into the exoplanet’s interior, while the warm material is easier to move because of the heat, and thus can flow to the interior of the planet. This can have abnormal consequences though, with the side whether the material flows upwards witnessing a large amount of volcanic activity.
Therefore, Browner believes that one side of the exoplanet would be completely covered with innumerable volcanoes while the other side would have almost none. But Dr Mier is of the opinion that more observations would be needed to confirm this conclusion.