Science CLUB

Plot twist in astronomy! 🪐👇🏻

NASA’s James Webb Space Telescope (JWST) has made a potentially groundbreaking discovery by detecting chemical signatures in the atmosphere of the exoplanet K2-18b, located 124 light-years away.

The molecules—dimethyl sulfide (DMS) and dimethyl disulfide (DMDS)—are particularly intriguing because, on Earth, they are produced almost exclusively by microbial life, such as marine phytoplankton. While these findings offer some of the most compelling signs yet of possible extraterrestrial biology, scientists emphasize the need for caution and further validation.

K2-18b is classified as a Hycean planet—a world with a hydrogen-rich atmosphere and possibly a global ocean beneath it. It is about 8.6 times the mass of Earth and orbits within the habitable zone of a cool dwarf star, where conditions could allow for the presence of liquid water. Previous JWST observations had already identified methane (CH₄) and carbon dioxide (CO₂) in the atmosphere, consistent with an environment that might support life.

The detection of DMS and DMDS reached a three-sigma confidence level, meaning there’s a 0.3% chance the signal is due to random noise. However, the gold standard for scientific discovery is five-sigma, or a 0.00006% chance, so more data is needed to confirm these results. Follow-up JWST observations totaling 16–24 hours are planned to improve precision and distinguish between the two molecules. Additionally, laboratory studies will explore whether non-biological processes could also generate these compounds under K2-18b’s specific atmospheric conditions.

Though this doesn’t confirm life, the findings are highly significant. The planet’s warm ocean and atmospheric makeup resemble the early Earth, making it a prime candidate in the search for life. As lead researcher Nikku Madhusudhan of the University of Cambridge cautioned, “It’s in no one’s interest to prematurely claim we’ve detected life. This is a groundbreaking step, but we need more data to confirm these signals.”

Whether the signals come from biology or unknown chemistry, K2-18b is rapidly becoming a landmark world in astrobiology.

RESEARCH PAPER 📄
Nikku Madhusudhan et al., "New Constraints on DMS and DMDS in the Atmosphere of K2-18 b from JWST MIRI", The Astrophysical Journal Letters (2025).

BREAKING NEWS
The Royal Swedish Academy of Sciences has decided to award the 2022 Nobel Prize in Physics to Alain Aspect, John F. Clauser and Anton Zeilinger “for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science.”

Alain Aspect, John Clauser and Anton Zeilinger have each conducted groundbreaking experiments using entangled quantum states, where two particles behave like a single unit even when they are separated. Their results have cleared the way for new technology based upon quantum information.

The ineffable effects of quantum mechanics are starting to find applications. There is now a large field of research that includes quantum computers, quantum networks and secure quantum encrypted communication.

One key factor in this development is how quantum mechanics allows two or more particles to exist in what is called an entangled state. What happens to one of the particles in an entangled pair determines what happens to the other particle, even if they are far apart.

For a long time, the question was whether the correlation was because the particles in an entangled pair contained hidden variables, instructions that tell them which result they should give in an experiment. In the 1960s, John Stewart Bell developed the mathematical inequality that is named after him. This states that if there are hidden variables, the correlation between the results of a large number of measurements will never exceed a certain value. However, quantum mechanics predicts that a certain type of experiment will violate Bell’s inequality, thus resulting in a stronger correlation than would otherwise be possible.

John Clauser developed John Bell’s ideas, leading to a practical experiment. When he took the measurements, they supported quantum mechanics by clearly violating a Bell inequality. This means that quantum mechanics cannot be replaced by a theory that uses hidden variables.

Some loopholes remained after John Clauser’s experiment. Alain Aspect developed the setup, using it in a way that closed an important loophole. He was able to switch the measurement settings after an entangled pair had left its source, so the setting that existed when they were emitted could not affect the result.

Using refined tools and long series of experiments, Anton Zeilinger started to use entangled quantum states. Among other things, his research group has demonstrated a phenomenon called quantum teleportation, which makes it possible to move a quantum state from one particle to one at a distance.

“It has become increasingly clear that a new kind of quantum technology is emerging. We can see that the laureates’ work with entangled states is of great importance, even beyond the fundamental questions about the interpretation of quantum mechanics,” says Anders Irbäck, Chair of the Nobel Committee for Physics.

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