Scientists are closely observing an Earth-like exoplanet that may possess water, utilizing NASA's James Webb Space Telescope, as announced in a recent news release. This intriguing exoplanet, known as TRAPPIST-1 e, orbits a red dwarf star called TRAPPIST-1. The TRAPPIST-1 system was first discovered in 2017 and consists of seven Earth-sized worlds, with planet e being the only one located at a distance where surface water could theoretically exist.
However, astronomers need to ascertain whether TRAPPIST-1 e has an atmosphere. To explore this possibility, NASA scientists employed the Webb telescope's Near-Infrared Spectrograph instrument to observe the TRAPPIST-1 system while planet e transited in front of its star. If TRAPPIST-1 e does have an atmosphere, the starlight that filters through it will be partially absorbed, resulting in dips in the light spectrum detected by the spectrograph. These dips will provide crucial information on whether the planet has an atmosphere and reveal the chemical composition of that atmosphere.
In addition to studying TRAPPIST-1 e, scientists are also examining the light spectrum of another exoplanet in the system, known as TRAPPIST-1 b. NASA researchers have determined that this planet lacks an atmosphere, allowing for a comparative analysis between its output and that of TRAPPIST-1 e. This comparison will help create a comprehensive understanding of the potential atmospheric conditions on TRAPPIST-1 e.
According to Néstor Espinoza of the Space Telescope Science Institute in Baltimore, Maryland, and a principal investigator for the research team, “Webb's infrared instruments are offering unprecedented detail. The initial four observations of TRAPPIST-1 e are providing valuable insights into what we should anticipate as further data becomes available.” Espinoza's research team recently published two scientific papers detailing their initial findings, expressing confidence that TRAPPIST-1 e does not possess a primary atmosphere.
A primary atmosphere, composed mainly of hydrogen and helium, would have existed when the planet formed. However, the active nature of the star TRAPPIST-1, characterized by frequent flares, may have stripped away this primary atmosphere due to intense stellar radiation. Nevertheless, researchers propose that TRAPPIST-1 e could have developed a heavier secondary atmosphere, a process similar to that which occurred on Earth. Future research using the Webb telescope will further explore the types and compositions of atmospheres that may exist on this exoplanet.
The potential for water on TRAPPIST-1 e is another fascinating aspect of this research. While NASA states that there may be no water present, the planet could also have vast oceans or extensive bodies of water. One hemisphere of TRAPPIST-1 e is perpetually shrouded in darkness, raising the possibility of ice formations as well. If liquid water does exist, NASA researchers suggest that a greenhouse effect could stabilize the atmosphere, allowing gases like carbon dioxide to maintain warmth on the planet.
We are only beginning to understand the remarkable scientific revelations possible with the James Webb Space Telescope. Ana Glidden, a post-doctoral researcher at the Massachusetts Institute of Technology's Kavli Institute for Astrophysics and Space Research, and lead researcher on the atmospheric studies for TRAPPIST-1 e, expressed excitement in NASA's news release: “It's incredible to measure the details of starlight around Earth-sized planets 40 light-years away and to explore the potential for life there. We are in an exhilarating new age of exploration.”
