It is logical to assume that extraterrestrial life will be found on the Earth’s twin. That is, we should find an extrasolar planet, which by its characteristics resembles the Earth. Well, researchers have already discovered such a world, but does he have chances for habitability?
We present to your attention Kepler-438 b! It is literally an earth twin, distant from us by 470 light years. The discovery was first announced in 2015. You can find a planet in the territory of the constellation Lyra near the star Kepler-438. It is a lonely red dwarf, reaching 0.54 solar in mass and 0.52 solar in radius.
The planet Kepler-438 b is only 12% larger than the Earth in size, and its index of similarity to our planet is 0.9 (maximum - 1), which is why in terms of similarity it is in the first place among all known exoplanets.
In addition, the exoplanet is also located in the zone of habitability of the star, and therefore receives enough light and heat to have liquid water on the surface. Spending about 35 days in one orbit. Some may suggest that such a proximity to the star should be detrimental to life, but the red dwarfs are inferior to the Sun in temperature and luminosity.
Comparison of Kepler-438 b and Earth For a long time, scientists believed that this planet was able to have comfortable climatic conditions of the Earth type with water, rain, clouds and air. Unfortunately, the reality was more sad. The fact is that Kepler-438 b really resembles the Earth, but you also have to take into account the activity of the native star.
In 2015, researchers found that the red dwarf Kepler-438 is a type of flashing stars. Moreover, these flashes occur once every few hundred days, and their power is 10 times higher than the solar indices (100 billion megatons of TNT). This suggests that the planet constantly receives a high dose of radiation, which led to the loss of the atmospheric layer and the destruction of all chances for the birth of life.
Therefore, when looking for life, you need to focus not only on the characteristics of the planet, but also to take into account the actions of the native star. However, researchers believe that if the exoplanet Kepler-438 b managed to save a powerful magnetic field, it could keep the atmospheric layer and primitive life forms in water.
Of course, in this case, the temperature rose to 60 ° C, but we know that life can exist in such extreme conditions on Earth. While the habitability of the “second Earth” remains in question.