Until now, astronomers have found no evidence of global tectonic activity on planets outside the solar system. Scientists from the University of Bern and the NCCR PlanetS National Center have found that material inside the planet LHS 3844b flows from one hemisphere to another and can cause numerous and very bright volcanic eruptions.
On Earth, plate tectonics is responsible for more than just mountain uplift and earthquakes. It is also an important part of the cycle that carries material from the interior of the planet to the surface and into the atmosphere, and then back under the earth’s crust. Thus, tectonics has a vital influence on the conditions that ultimately make the Earth habitable.
Until now, researchers have found no evidence of global tectonic activity on planets outside the solar system. Recently, however, a team of researchers led by Tobias Meyer of the Center for Space and Habitability (CSH) found evidence of streams inside the planet LHS 3844b. She
located 45 light years from Earth. The results are published in the Astrophysical Journal Letters.
“It is very difficult to observe signs of tectonic activity because they are usually hidden under the atmosphere,” explains Meyer. However, recent results have shown that LHS 3844b probably has no atmosphere at all. It is a rocky world that is slightly larger than Earth, orbits very close around its star. Because of this, one side of the planet is in constant daylight and the other side is in constant night. Likewise, the same side of the moon always faces the earth. However, the “dark” half is illuminated by bright volcanic eruptions.
Due to the lack of an atmosphere that protects the planet from intense radiation, the planet’s surface reaches 800 ° C. The night side freezes. Temperatures here can drop below –250 ° C.
Scientists have suggested that such a sharp temperature contrast could affect the flow of material inside the planet.
To test their theory, the team ran computer simulations with varying material strengths and internal heat sources – heat from the planet’s core and decay of radioactive elements. The simulations included the large surface temperature contrast created by the host star.
Most simulations showed that there was only an updraft on one side of the planet and a downdraft on the other. Thus, material flowed from one hemisphere to another. Surprisingly, the direction was not always the same. The scientists expected material on the hot daytime side to be lighter and therefore flow upward and vice versa. However, the simulation also showed a reverse flow direction.
Such a flow of matter could have strange consequences. You can imagine half of the planet with countless volcanoes – the volcanic hemisphere – and one almost without them.