Volcanic activity and mantle dynamics shape the lava world K2-141 b

Star system: K2-141 | Distance from the Sun: 202 light years

K2-141 b is an ultra-short period planet, known as a lava world, that orbits very close to its star. This extreme environment causes one side of the planet to be extremely hot, covered by a magma ocean, while the other side remains much cooler and solid. Scientists used computer models to study how the planet's interior moves and how this affects volcanic activity, especially on the nightside, which is not directly heated by the star.

The research explored different ways the planet's mantle, the layer beneath the crust, could behave. In some models, the mantle is strong and does not easily break, while in others it is weaker and allows more movement. The results show that hot material rises at the points facing toward and away from the star, while cooler material sinks at the boundary between the hot and cold sides. This movement helps recycle the crust and leads to a unique type of tectonics. The thickness of the magma ocean can vary, and continuous volcanic eruptions on the nightside slowly release gases like carbon dioxide and water vapor from the planet's interior.

Over billions of years, these eruptions could release large amounts of gas, but the heat signals from these eruptions are too faint to be detected with current technology. However, more gas is released near the boundary between the hot and cold sides, and future studies may be able to detect these gases in the planet's atmosphere using special techniques.

Key findings
- K2-141 b has a magma ocean on the dayside and a solid crust on the nightside due to extreme temperature differences.
- Mantle convection creates upwellings and downwellings that drive a unique form of tectonics and recycle crustal material.
- Nightside volcanic eruptions gradually deplete the mantle of gases like carbon dioxide and water vapor.
- The heat from nightside eruptions is too weak to be detected with current instruments.
- Increased gas release near the day-night boundary may produce atmospheric signals detectable in future observations.

Scientific study

Mantle convection and nightside volcanism on lava world K2-141 b (external link)