According to the latest reports, it seems that there are potential signs of life on the exoplanet called K2-18b. Here are the latest details about the discovery below.
Potential life signs on the exoplanet?
Data collected by the James Webb Space Telescope (JWST) has revealed that an exoplanet orbiting a star in the Leo constellation has some of the chemical markers that, on Earth, are associated with living organisms.
However, these indications are vague, so it is unclear how likely it is that alien life exists on this exoplanet.
Exoplanets are planets that orbit stars other than our Sun. The exoplanet in question is called K2-18b, named after the red dwarf star K2-18 around which it orbits.
The K2-18 system also has a second planet, K2-18c. The star itself is dimmer and cooler than the Sun, which means that for the exoplanet to receive the same level of light as Earth, it needs to be much closer to its star than our planet is to the Sun.
The exoplanet system is located approximately 124 light years away, which is relatively near in astronomical terms. However, it is challenging to determine the conditions like on this exoplanet as we don’t have the capability to capture direct images of the planet.
Experts are equipped with powerful telescopes and techniques that enable us to determine what the star is like and calculate the distance of the exoplanet from it.
To assess the potential of K2-18b, the exoplanet, for life, it is necessary to determine how much light it receives from its star. K2-18b is situated closer to its star than the Earth is to the Sun, at approximately 16% of the distance. Another important measurement is the power output of the star, which is the total amount of energy it emits per second. K2-18’s power output is 2.3% of that of the Sun.
When we talk about the possibility of life on other planets, we often use the term “habitable zone”, which refers to the zone where the average surface temperature would allow water to exist in a liquid state, a necessary condition for life.
In 2019, the Hubble Space Telescope detected water vapour on K2-18b, indicating that liquid water might exist on its surface. Scientists now believe that there are vast oceans on the planet.
This discovery caused a lot of excitement at the time, but more evidence was needed to confirm the presence of life. Recently, the James Webb Space Telescope (JWST) detected carbon dioxide, methane, and possibly dimethyl sulfide (DMS) in the planet’s atmosphere. The discovery of DMS is particularly interesting, as it is only produced on Earth by algae.
There is currently no known natural process that can produce DMS without the involvement of a life-form.
There are a few signs that suggest that K2-18b may be a good candidate for finding extraterrestrial life. However, it’s not that simple, since we cannot be certain about the accuracy of these indications.
To determine the composition of an exoplanet’s atmosphere, scientists observe the light that passes through the planet’s atmosphere from a distant source, such as a star or a galaxy. The chemicals in the atmosphere absorb light in specific wavelengths, which can then be used to identify them.
You can check out more details about the story in the original article in Astronomy.
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