One of the most extreme discoveries outside of our Solar System is the lava planets: fiery and ultra-hot worlds spinning so close to their host star that some of their regions are oceans of molten lava. The exoplanet K2-141b is one of them and its characteristics are detailed in a scientific article published this Tuesday.
K2-141b, discovered by the Kepler mission, is especially strange, with an atmospheric and meteorological cycle that causes evaporation and precipitation of rocks, roaring supersonic winds at more than 5000 kilometers per hour and an ocean of magma of hundred kilometers deep.
And it is that K2-141b is an exoplanet the size of the Earth, with a surface, an ocean and an atmosphere composed of the same ingredient: rocks.
The characterization of the planet, published in the magazine Monthly Notices of the Royal Astronomical Society and carried out by researchers from the Canadian University of McGill, the University of York (United Kingdom) and the Institute of Scientific Education (India), predicts that the extreme climate of the exoplanet it could permanently change its surface and atmosphere.
“The study is the first to make predictions about the weather conditions on K2-141b that may be detected hundreds of light years away with state-of-the-art telescopes like the James Webb Space Telescope, “explains lead author Giang Nguyen of York University.
By analyzing the exoplanet’s illumination pattern, the team found that about two-thirds of K2-141b lives under perpetual daylight, while the night side remains at a temperature of -200 C.
K2-141b belongs to a subset of rocky planets that orbit very close to its star and that proximity maintains the exoplanet gravitationally locked in place, which means that the same side is always facing the star, with an estimated temperature of about 3000 C, enough heat to melt the rocks and vaporize them, thus creating a thin atmosphere in some areas.
But the most surprising thing is that this rock vapor atmosphere created by extreme heat suffers precipitation And just like the water cycle on Earth, where water evaporates, rises into the atmosphere, condenses, and falls back as rain, so do sodium, silicon monoxide, and silicon dioxide. at K2-141b.
On Earth, the rain returns to the oceans, where it will evaporate again and the water cycle repeats, and in K2-141b, the mineral vapor formed by the evaporated rock is swept to the side of the frozen night by supersonic winds and the rocks “rain” back into an ocean of magma. The resulting currents flow back to the hot side of the exoplanet’s day, where the rock evaporates again.
But the cycle of K2-141b is not as stable as that of Earth, according to scientists, who predict that the composition of the mineral will change over time.
“All rocky planets, including Earth, started out as molten worlds but then they quickly cooled and solidified. The lava planets allow us to take a look at this stage of planetary evolution, “says Nicolas Cowan of McGill University.
To show that these predictions are correct, the scientists will now analyze the data from the Spitzer Space Telescope, which should take a first look at the exoplanet’s day and night temperatures, until the James Webb Space Telescope, due to launch in 2021, also verifies that the atmosphere behaves as this study predicts.