Scientists discover evidence of life on a distant planet

Is anybody out there?

In a historic discovery, scientists have revealed strong and unprecedented evidence that could point to life beyond the solar system.

James Webb Space Telescope

Scientists were using the James Webb Space Telescope when they identified the presence of chemicals that may be linked to the existence of life.

The exoplanet K2-18

These substances were detected in the atmosphere of the exoplanet K2-18 b, located outside our solar system.

Photo: NASA, CSA, ESA, J. Olmsted (STScI), Science: N. Madhusudhan (Cambridge University)

Gases indicate potential life

The two gases identified were dimethyl sulfide (DMS) and dimethyl disulfide (DMDS). On Earth, these compounds are produced exclusively by living organisms, especially phytoplankton, which are microscopic algae present in the oceans, Reuters reported.

Photo: NASA, ESA, CSA, STScI, Klaus Pontoppidan (STScI)

Promising discovery

Another factor that caught the attention of scientists is that the quantities of gases found exceed 10 parts per million, much higher than the levels recorded on Earth.

Microbial life

According to the researchers, this discovery raises the possibility that the exoplanet is inhabited by a large number of microscopic life forms.

Cambridge researchers

The study was conducted by researchers at the University of Cambridge and published in the scientific journal Astrophysical Journal Letters.

Lead author

“This is the first evidence of a potentially inhabited alien world,” said Nikku Madhusudhan, an astrophysicist at the University of Cambridge’s Institute of Astronomy and lead author of the study, quoted by Reuters.

Caution called for

Still, scientists warn that this is not proof of life, but rather a possible sign of biological activity. Therefore, the data should be analyzed with caution, and new observations will be needed to confirm the theory, as reported by the University of Cambridge.

What is K2-18 like?

The planet K2-18 b, analyzed in the study, is much larger than Earth: it has a mass 8.6 times bigger and a diameter about 2.6 times greater. It is located in the so-called “habitable zone” – which means that it is neither too hot nor too cold to have liquid water.

Distance from Earth

This planet orbits a red dwarf, a type of star that is smaller and less luminous than the Sun. It is approximately 124 light-years from Earth, in the constellation Leo.

Transit Method

To identify the chemical composition of an exoplanet's atmosphere, astronomers use the so-called transit method. It works like this: when the planet passes in front of its star, some of the light passes through its atmosphere before reaching the telescope. The James Webb then analyzes this filtered light, allowing the atmospheric composition to be established.

More accurate data

The James Webb telescope has already indicated early signs of the presence of DMS. But the scientists used a different instrument and a new spectrum of light to obtain more precise data, the BBC reported.

Photo: Pexels Pixabay

What about intelligent life?

Asked about the possibility of multicellular or even intelligent life, Nikku Madhusudhan told Reuters: ""We won't be able to answer this question at this stage. The baseline assumption is of simple microbial life."

A new era for astronomy

Decades from now, we may look back at this point in time and recognise it was when the living universe came within reach,” said Madhusudhan on the Cambridge University website. “This could be the tipping point, where suddenly the fundamental question of whether we’re alone in the universe is one we’re capable of answering.”

The search continues

The researcher also highlighted that there are several initiatives underway to search for signs of life in our solar system, with evidence of possible habitable environments on Mars and Venus and on some icy moons.