A year on this planet lasts only 25 days

Astronomers have announced another significant discovery regarding the exoplanet located approximately 49 light-years from Earth, LHS 1140 b . New studies provide stronger confirmation that an atmosphere may exist on this celestial body. The results of the scientific work were published in the journal Science .

During the study, scientists observed the planet as it passed in front of its star. At that moment, starlight passes through the atmosphere, allowing for the detection of traces of gases within it. Experts were able to record signs indicating the presence of helium in the atmosphere using this exact method.

Interestingly, while the helium signal was detected in 2024 observations, it was barely observed in 2025. Scientists explain this by suggesting that gas escape from the atmosphere is not constant or that stellar activity fluctuates over time.

Experts believe that the presence of helium suggests the planet's atmosphere may have been preserved for billions of years. They hypothesize that the upper atmosphere consists mainly of helium, while heavier gases such as nitrogen, carbon dioxide, and water vapor may exist in the lower layers. However, these substances have not yet been directly confirmed.

LHS 1140 b is located in its star's "habitable zone." This means that under certain conditions, liquid water could exist on its surface. At the same time, scientists emphasize that such a location does not automatically imply the existence of life on the planet.

Previous studies suggested that this exoplanet is not a gas giant, but rather a rocky planet that may possess large water reserves. Calculations indicate that water could account for 9–19 percent of its total mass.

Another hypothesis by scientists is that LHS 1140 b is tidally locked to its star. Therefore, it is likely that one side experiences perpetual daylight, while the other remains in constant darkness.

Climate models suggest that much of the planet may be covered in ice. However, there is a high probability that a liquid ocean exists on the side facing the star. It has been noted that this ocean might resemble a giant eye in appearance.

According to some calculations, temperatures in the central part of the ocean could rise to 20 degrees Celsius. Such an environment depends on the atmospheric composition and the greenhouse effect, where nitrogen and carbon dioxide could help retain heat to support liquid water.

LHS 1140 b is approximately 1.7 times larger than Earth, with a mass 5–6 times greater. The planet orbits a red dwarf star, which is smaller and cooler than the Sun, once every 25 days.