Scientists have identified a far-off planet that may be completely enveloped in a vast expanse of water, which could potentially broaden the scope of our hunt for livable environments beyond our own planet.

The recent findings from the JWST, operated by Nasa, discovered water vapor as well as traces of methane and carbon dioxide in the atmosphere of a distant exoplanet that is approximately 70 light years away. Based on their analysis, scientists from the University of Cambridge believe that this chemical composition suggests the exoplanet is a water world with a vast ocean covering its surface, along with a hydrogen-rich atmosphere. However, they do not believe this would create a pleasant, habitable environment.

According to Professor Nikku Madhusudhan, who headed the research, the temperature of the ocean could potentially reach over 100 degrees Celsius. Even at extreme atmospheric pressure, such a hot ocean may remain in liquid form, but its habitability is uncertain.

The findings of a study published in Astronomy and Astrophysics Letters suggest that TOI-270 d, an exoplanet, may have a thick atmosphere composed of hydrogen and water vapor on top of a rocky surface. However, a team from Canada disputes this interpretation, citing their own observations of the planet and claiming that it would be too hot for liquid water at approximately 4,000 degrees Celsius.

Regardless of which perspective prevails, the recent findings highlight the incredible knowledge that James Webb is providing about planets outside of our solar system. Through the telescope, we are able to study the starlight that has passed through the atmospheres of these planets, revealing detailed information about the chemical makeup. This allows astronomers to gain insight into the surface conditions of these planets and assess the potential for life to exist.

Scientists have found evidence supporting the presence of an ocean on TOI-270 d by observing the absence of ammonia. According to chemical principles, an abundance of hydrogen in the atmosphere should lead to the naturally occurring residence of ammonia. However, since ammonia is easily dissolved in water, its absence in the atmosphere suggests that it is being depleted due to the existence of an ocean below. Lead researcher Madhusudhan suggests that this planet could potentially be classified as a “hycean” world, with a water ocean underneath a hydrogen-rich atmosphere.

The circumstances on TOI-270 d would be greatly contrasting to those on Earth as it is a tidally locked planet. This means that one side of the planet is constantly facing its star, while the other side remains in constant darkness, resulting in extreme differences in temperature.

View image in fullscreen

According to Madhusudhan, the day side of the ocean would be very warm, but the night side could potentially be hospitable. However, the atmosphere would be intense, with significantly higher pressure compared to Earth’s surface, and steam emerging from the ocean. It is predicted that the ocean would have extreme depths of tens to hundreds of kilometers, with a bed of high-pressure ice and a rocky core beneath that.

Björn Benneke, a professor at the University of Montreal, conducted further studies on the planet and raises doubts about the possibility of it being a “hycean world.” He stated that the temperature is too high for liquid water to exist. Additionally, he noted that the atmosphere is filled with a significant amount of water vapor, making the existence of an ocean unlikely. According to Benneke’s estimation, the surface temperature could reach 4000C, causing the water to exist in a supercritical state where the line between liquid and gas is blurred. He described it as a thick, hot fluid.

Both teams observed the presence of carbon disulfide, a compound associated with biological processes on our planet, but can also arise from other sources. However, there were no indications of the presence of another molecule indicative of life, dimethyl sulfide (DMS).

Madhusudhan stated that it is not possible to connect carbon disulphide to biological processes. He also explained that this molecule can be easily produced in an atmosphere rich in hydrogen. However, measuring this unique molecule could potentially lead to the identification of habitable planets in the future.

“We must exercise caution when discussing the discovery of this type of object,” he cautioned. “The public may easily jump to the conclusion that we have already found signs of life.”

Astrophysicist Dr. Jo Barstow from Open University, who was not involved in the recent research, expressed her excitement for the potential of studying these small planets with the JWST. She also noted that these environments are completely new and do not have any equivalent in our solar system.

Barstow stated that additional research to determine the extent of water vapor in the atmosphere would provide more insight into the likelihood of an ocean. She also noted the interesting coincidence of two teams observing the same data and reaching the same conclusions about its chemical composition.

Source: theguardian.com