For the first time ever: An atmosphere has been identified around an Earth-like planet
Astronomers have detected helium gas for the first time in the atmosphere of LHS 1140 b - a rocky planet in the habitable zone, located 464 trillion km away. The breakthrough, made using the Magellan telescope in Chile, proves that Earth-like worlds can maintain a gas envelope for billions of years.
An exciting breakthrough in space exploration: astronomers have managed to detect for the first time, directly, helium gas in the atmosphere of LHS 1140 b - a rocky planet located outside the solar system, at the perfect distance from its parent star. This allows for temperatures that are not too hot or too cold, and are suitable for the existence of water in a liquid state. The new findings, published in the scientific journal Science and led by Dr. Colin Cherubim, are considered a significant step on the way to locating Earth-like worlds.
The researchers used the advanced WINERED infrared spectrograph, installed on the Magellan telescope in Chile. They measured the star's light while the planet passed in front of it - a process known as transit spectroscopy. The planet's atmosphere absorbed certain wavelengths, thereby revealing the spectral signature of helium.
The measurements showed that helium is escaping into space at a rate of hundreds of thousands of kilograms per second. Despite this escape, its very presence testifies with certainty that the rocky world manages to maintain a gas envelope around it. The characterization of the data was defined by astronomers as leading in the field, and the collected data are considered statistically solid. The researchers estimate that this atmosphere may last for more than three billion years.
Who are you, LHS 1140 b?
The planet, which is located at a vast distance of about 464 trillion kilometers from us, is of the "super-Earth" type. Its mass is 5.6 times that of Earth and its radius is 1.7 times larger. In addition, it receives about 42% of the amount of radiation that the Sun sends to Earth, and its surface temperature is similar to conditions known to us on Earth and Mars. Its density even hints at the presence of large amounts of water.
The researchers clarify that helium alone is not a sign of life, and the atmosphere of LHS 1140 b is fundamentally different from that of Earth. In addition, current instruments are not yet capable of penetrating the lower layers and detecting heavier gases such as nitrogen or carbon dioxide.
The unique geometric opportunity of LHS 1140 b allows for a rare glimpse into rocky worlds that are very difficult to detect using standard methods. The team has already begun follow-up observations using the Hubble Space Telescope and the James Webb Space Telescope, in the hope of finding further clues that will help understand whether this is a world that could support life.
