We know from the solar system that sometimes it just depends on luck whether a planet becomes habitable or a hellhole after its formation. Earth and Venus are similar in many ways, but there is a big difference between them in terms of life. Can we detect this difference from several light years away? American research group He imagined what he could realize While observing one of these exoplanets with the James Webb Space Telescope (JWST). The universe today mentioned. The researchers created simulations of the type of spectral components that would be expected for the two types of planets, and explored what hinders and helps the distinction.
In the simulation, six Earth exoplanets and six Venus exoplanets, each with a different amount of atmospheric carbon dioxide, were placed 40 light-years away in orbit around a red dwarf star like TRAPPIST-1, famous for its planetary system. This system is very promising, and the James Webb Space Telescope has already examined the two innermost planets and found them to be bare rocks and without an atmosphere. In a system of 7 planets, 3-4 of them may orbit in the habitable zone.
In the simulation, the planets are placed in such a way that they orbit in a place where even processes that end in the case of Venus can occur. The James Webb Virtual Space Telescope was then pointed at that planet, which analyzed the planet’s signals with NIRSpec’s near-infrared spectrometer. A particular atmospheric component, chemical element or molecule gives off signals that are specifically characteristic of it, which can be detected in spectrometer measurements. This device detects peaks in the planet’s light spectrum, and thus the components represented by the peaks.
Of course, the situation is not that simple: many components have very similar signals, and one can mask the signal of the other, so certain molecules are particularly difficult to detect. In addition, the atmosphere of the planet in question covers the signal of some particles like a shroud. However, these difficulties do not mean that it is impossible!
Through the simulations, it became clear what observable signs should be paid special attention to in critical situations, if they want to determine which group a planet belongs to by examining the atmosphere of an exoplanet.
First, it is important to determine whether a planet has an atmosphere, and carbon dioxide is excellent for this, because it leaves a visible signal in the case of cloudy and hazy planets and planets with clear air. However, this gas is no longer suitable for differentiation, on the one hand, because it can be present in both types, and on the other hand, because its signal coincides with that of water and methane, which causes a great deal of confusion in the matter. Results.
However, there is one distinct element that can be found in the atmospheres of Venus-like planets, but not Earth-like planets: sulfur dioxide. This compound reacts quickly with atmospheric water and disappears from the atmosphere of Earth-like planets. In Hungarian, if sulfur dioxide is present, it is a sign of the world of Venus. However, this again has a small twist: sulfur dioxide in the atmosphere doesn’t last long in the case of Venus either, as the ultraviolet component of sunlight here destroys these molecules, so relatively little of it can be seen in the planet’s spectrum. There was a positive development at the end of the story. TRAPPIST-1 is a cool red dwarf star, so its ultraviolet radiation is weaker, and as a result, it handles the gases of its atmosphere much more gently than our Sun. That is, if the atmosphere of an orbiting planet contained sulfur dioxide, it would not disintegrate so easily.
In the case of methane, there are components in the spectrum that are different from carbon dioxide, so this can also be used. The presence of methane can also be a good measure to prove what type of Earth is extraterrestrial. In addition, researchers have found that the surest sign of the presence of life is the presence of methane. And It also has oxygen in its atmosphere.
The researchers also calculated the amount of time a space telescope would have to spend observing each planet to observe these features. Fortunately, this turned out to be within the time frame allocated for each measurement during the device’s use period.
