Astronomers analyzed available information on a planet K2-18b Which is outside the solar system, including the structure and composition of its atmosphere, have come to the conclusion that The planet could have all the conditions for life to exist.
The results of the study published a magazine Astrophysical Journal Letters, Where a planet was discovered K2-18b With a radius of 2.6 times greater than the Earth, and a mass of more than 8.6 in 2015, in the orbit of the red dwarf star in the Leo constellation about 124 light-years from Earth.
In 2019, results of data analysis from the Kepler, Spitzer and Hubble space telescopes showed that there is a large amount of water vapor present in the planet’s atmosphere..
This was the first planet outside the solar system to discover water vapor, as well as the first planet outside the solar system where life could theoretically exist.
To assess the likelihood of such a scenario, British scientists from Cambridge University used observations about the atmosphere, as well as data on the mass and radius of the outer planet K2-18b, By performing digital simulations and discovering that liquid water may be present on the planet’s surface, the temperature and composition of the atmosphere enriched with hydrogen create habitable conditions.
“Water vapor has been discovered in the atmosphere of a number of exoplanets, but even if the planet is in a habitable area, this does not necessarily mean that there are appropriate living conditions on the surface,” said Niko Madhosudan, director of the study.
To determine the potential for habitability, it is important to understand the internal and weather conditions on the planet, in particular, whether liquid water is present on the surface, “according to the magazine..
Because of the size K2-18b Big, it was previously assumed that the planet would be more like a smaller version of Neptune than an enlarged version of Earth. Scientists had thought that under the thick hydrogen atmosphere in this microscopic neptune, there would be a layer of water under high pressure, and under it – a core made of stone and iron. If the hydrogen shell is very thick, then the temperature and pressure on the surface of the water layer will be too high to support life.
After further studies, it turned out that despite the size K2-18b, The hydrogen shell does not have to be very thick, and the water layer may have suitable conditions to preserve life.
The researchers confirmed that the planet’s outer atmosphere is rich in hydrogen and contains a large amount of water vapor, and they also found that methane and ammonia levels were lower than expected in relation to this formation and atmospheric pressure. But they are not sure that this fact can be unambiguously linked to the biological processes that occur in K2-18b.
According to the study, the atmosphere does not exceed 6 percent of the total mass of the planet, and is likely much less, and the minimum level of hydrogen content in it can drop to one million percent, which is similar to the content in the Earth’s atmosphere..
Temperatures and pressure can also be on the surface of the covered water circumference K2-18b “floor“.
The obtained results open up new possibilities for astronomers to search for potentially populated worlds among a large group of exoplanets, much larger than the size of Earth, but smaller than Neptune..
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