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Out in the cosmos far from the vicinity of our Sun, there are 4,000 strange and distant worlds orbiting other stars.
These exoplanets are tantalizing clues that there are other places in the universe where life could thrive, but they also offer unprecedented insights into how our Solar System was born, including what our Earth might have looked like during its early years. Young people.
And while Earth may be extraordinarily beautiful now, a newly discovered exoplanet suggests that in its youth, or planet, it was a very, very different place: a strange world, with an ocean of magma, supersonic winds, and vaporized rocks.
The new planet is detailed in a study published this week on Royal monthly notices Astronomical Society.
Dubbed K2-141b, this exoplanet is located about 200 light years from Earth. It is classified as a super-Earth, which means that it has a mass greater than that of our planet, but much less than that of the ice giants of the Solar System Uranus and Neptune, which are 14.5 and 17 times more massive than Earth. .
Specifically, K2-141b is only five times as massive as Earth.
The planet was first found in the year 2018 orbiting a K-type star, or orange dwarf. The orbit of K2-141b is close to its host star – it takes only 0.3 Earth days to complete one orbit, at a distance of 0.00716 astronomical units. An astronomical unit is the distance between the center of the Earth and the center of the Sun – converted to miles, K2-141b is approximately 670,000 miles from its star. For context, Mercury, the closest planet to our Sun, is nearly 29 million miles from the Sun.
And at such a short distance from the star, things on K2-141b can get weird, to say the least.
Weather forecast – In this new study, the team of scientists used computer simulations to predict weather conditions on K2-141b. What they found is unlike anything we can imagine here on Earth.
The exoplanet’s surface, ocean, and atmosphere are all made up of rocks.
The exoplanet is so close to its star, it’s locked in place by the star’s gravitational pull. As a result, two thirds of the exoplanet are exposed to permanent sunlight, with temperatures reaching 3,000 degrees Celsius.
Meanwhile, temperatures on the dark side reach freezing temperatures below -200 degrees Celsius.
On the sunny side of the planet, temperatures are warm enough not only to melt the planet’s rocky surface, but also to melt it. vaporize them, creating an atmosphere of rock vapor.
On Earth, water vapor rises into the atmosphere, condenses and falls back in the form of rain. So also on K2-141b, but instead of water, the vapor consists of sodium, silicon monoxide and silicon dioxide. The mineral vapor formed by the evaporated rock is then carried to the freezing night side of the exoplanet by supersonic winds, where the rocks fall back into an ocean of magma.
The ocean currents then ebb to the sunny side, where the rock evaporates once again. Rinse and repeat.
But scientists also predict that this cycle could change over time. They theorize that the composition of mineral rain can slowly change over time with each repetition of the cycle, also causing the exoplanet’s surface and atmosphere to change.
As strange as this exoplanet is, its bizarre climate and composition offer a glimpse of how our planet began its life as well. Astronomers believe that rocky planets like Earth originated as fused planets that eventually cooled and solidified over time.
“The lava planets give us a rare glimpse at this stage of planetary evolution,” Nicolas Cowan, a professor in the Department of Earth and Planetary Sciences at McGill University and co-author of the new study, said in a statement.
In essence, K2-141b could be the planetary equivalent of the embarrassing images of Earth’s children.
Abstract: Transit searches have discovered Earth-sized planets orbiting so close to their host star that their surface should be molten, so-called lava planets. We present idealized simulations of the atmosphere of the lava planet K2-141b and calculate the return flow of the material through the circulation in the magma ocean. We then compare how pure atmospheres of Na, SiO or SiO2 would impact future observations. The more volatile atmosphere of Na is the densest followed by SiO and SiO2, as expected. Despite its low vapor pressure, we find that a SiO2 atmosphere is easier to observe via transit spectroscopy due to its greater scale height near the day-night terminator and the planetary radial velocity and acceleration are very high. , facilitating high dispersion spectroscopy. The special geometry resulting from very small orbits allows a wide range of limb observations for K2-141b. After determining the magma’s ocean depth, we deduce that the ocean circulation required for steady-state SiO flux is only 10-4 m / s while the equivalent return flux for Na is several orders of magnitude greater. This suggests that a stable Na atmosphere cannot be sustained and that the surface will evolve over time.
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