"Super Earth" K2-18b Researchers rejoice at clear evidence of extraterrestrial life
The exoplanet K2-18b has often caused a stir. Now researchers have found chemical compounds on the "super-Earth" that can only be produced by living beings. It is a turning point.
No time? blue News summarizes for you
- An international team of researchers may have taken an important step forward in the search for life outside our solar system.
- Astronomers have discovered signs of two important chemical sulphur compounds in the atmosphere of the so-called "super-Earth" K2-18b.
- The planet is 124 light years away and lies in the habitable zone of its star.
Life outside the Earth? Maybe someone is out there! Astronomers are rejoicing over a sensational discovery on the exoplanet K2-18b (124 light years from Earth): With the help of the James Webb Space Telescope, the University of Cambridge found indications of the two substances dimethyl sulphide (DMS) and dimethyldisulphide (DMDS) in its atmosphere.
These are the clearest indications yet of life outside our solar system! On Earth, these compounds are produced by microorganisms, such as phytoplankton in the oceans, the group reports in the journal "The Astrophysical Journal Letters".
For the study, the team used the fact that K2-18b regularly passes in front of its home star - a red dwarf - and temporarily shadows it. During such a transit, the star shines through the planet's atmosphere from behind. In principle, this makes it possible to analyze the chemical composition of the atmosphere.
However, study leader Nikku Madhusudhan admits that there are still some uncertainties. For one thing, the substances could also have been formed in a different, previously unknown way. Furthermore, their presence in the planet's atmosphere has not been proven with absolute certainty.
"Super-Earth" is around two and a half times the size of Earth
The planet K2-18b in the constellation Leo has long been the focus of astronomers. It was discovered in 2015 and is 8.6 times heavier and 2.6 times larger than Earth. A few years ago, researchers found water on this so-called super-Earth for the first time on a planet in the life-friendly zone of another star.
The life-friendly or potentially habitable zone is the area around a star in which the temperatures allow the existence of liquid water on a planet. Liquid water is the basic prerequisite for life as we know it.
Can the observations be confirmed?
Methane and carbon dioxide have also already been found in the planet's atmosphere. Madhusudhan's team had also discovered indications of DMS in the near infrared range. These have now been confirmed for the mid-infrared range. This is therefore a second piece of evidence, determined with a different instrument and at a different wavelength, Madhusudhan is quoted as saying in a statement from his university. "The signal came through strong and clear."
However, if the observations are correct, the concentration of the compounds would be thousands of times higher than on Earth: here they are less than one particle per billion particles, whereas on K2-18b it would be at least ten particles per million. Now the observations need to be confirmed, the researchers write. "The key question now is whether we are able to identify the signatures of life on other worlds."
