NASA’s James Webb Space Telescope is currently observing TRAPPIST-1 e, an Earth-like exoplanet that may harbor water. This intriguing world, orbiting the red dwarf star TRAPPIST-1, is part of a system discovered in 2017, which consists of seven Earth-sized planets. Among them, TRAPPIST-1 e stands out as the only one positioned at a distance where surface water could feasibly exist, according to NASA’s findings. However, the presence of an atmosphere remains uncertain, prompting ongoing observations by scientists.
To investigate potential atmospheric conditions, NASA has utilized the Webb telescope’s Near-Infrared Spectrograph, directing it toward the TRAPPIST-1 system during a transit of planet e across its host star. If TRAPPIST-1 e possesses an atmosphere, it will absorb certain wavelengths of starlight, producing characteristic dips in the light spectrum that the spectrograph detects. These variations will assist scientists in determining the chemical composition of the planet’s atmosphere, if it exists.
In conjunction with this study, researchers are focused on another exoplanet, TRAPPIST-1 b, which has been confirmed to lack an atmosphere. By comparing the spectral outputs of TRAPPIST-1 e and TRAPPIST-1 b, astronomers hope to gain a clearer understanding of the atmospheric possibilities surrounding planet e.
Néstor Espinoza from the Space Telescope Science Institute in Baltimore, Maryland, who leads the research team, emphasized the significance of Webb’s infrared instruments, stating, “Webb’s infrared instruments are giving us more detail than we’ve ever had access to before. The initial four observations we’ve made of planet e showcase what we can expect as further data arrives.” Recently, Espinoza and his team published two scientific papers detailing these initial findings.
While researchers speculate about the atmosphere of TRAPPIST-1 e, they express confidence that it does not possess a primary atmosphere composed of hydrogen and helium, as this would have existed at the planet’s formation. The star’s high activity and frequent flares may have stripped away such an atmosphere. Nevertheless, there remains the possibility that the planet has developed a secondary atmosphere, which could comprise various gases, similar to the process observed on Earth and other celestial bodies. Subsequent observations with the Webb telescope are anticipated to clarify the nature and makeup of any potential atmosphere.
The potential for water on TRAPPIST-1 e is also a point of consideration. NASA notes the possibility that the planet may be dry, feature an expansive ocean, or contain large regions of water. The unique rotational pattern of TRAPPIST-1 e—where one side remains in perpetual darkness—introduces the likelihood of ice formation as well. Should TRAPPIST-1 e house liquid water, the researchers theorize that it could facilitate a greenhouse effect, enabling atmospheric gases like carbon dioxide to help stabilize and warm the environment.
Ana Glidden, a post-doctoral researcher at MIT’s Kavli Institute for Astrophysics and Space Research and the lead investigator on atmospheric conditions for planet e, remarked, “We are really still in the early stages of learning what kind of amazing science we can do with Webb. It’s incredible to measure the details of starlight around Earth-sized planets 40 light-years away and learn what it might be like there, if life could be possible there. We’re in a new age of exploration that’s very exciting to be a part of.”
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