James Webb Space Telescope Detects Temperature on TRAPPIST-1 b Exoplanet
The James Webb Space Telescope (JWST) has detected the temperature of the rocky exoplanet TRAPPIST-1 b, which is one of the closest Earth-sized exoplanets to our solar system. The measurement, which is based on the planet's thermal emission, suggests that TRAPPIST-1 b has no significant atmosphere.
JWST's Mid-Infrared Instrument (MIRI) was used to measure the planet's temperature during a secondary eclipse, in which the planet passes behind its star and blocks out some of its light. The team used a technique called secondary eclipse photometry to compare the brightness of the system before and during the eclipse, which allowed them to calculate how much infrared light is being emitted by the planet.
The results show that the dayside of TRAPPIST-1 b has a temperature of about 500 kelvins (roughly 230°C). This is consistent with the temperature expected for a tidally locked planet with a dark-colored surface and no atmosphere.
"This is the first time we've been able to measure the temperature of a rocky exoplanet in such detail," said lead author Dr. Hannah Wakeford of the Centre for Astrophysics Research at the University of Hertfordshire, UK. "The results suggest that TRAPPIST-1 b is a very hot planet, and that it may be too hot to support life as we know it."
The lack of an atmosphere on TRAPPIST-1 b is also surprising, as previous studies had suggested that the planet could have a thick atmosphere of water vapor. However, the new results suggest that the planet's atmosphere may have been stripped away by the intense radiation from its star.
"This is a very exciting result," said Dr. Björn Benneke, co-author of the study from the University of Montreal, Canada. "It shows that JWST is capable of making detailed observations of exoplanets, and it gives us new insights into the atmospheres of these worlds."
The team plans to continue studying TRAPPIST-1 b with JWST, and they hope to learn more about its composition and atmosphere in the future.
Implications for the Search for Life.
The discovery that TRAPPIST-1 b has no significant atmosphere is a setback for the search for life beyond Earth. Atmospheres play an important role in regulating planetary temperatures and protecting life from harmful radiation. However, the results do not rule out the possibility that TRAPPIST-1 b could still be habitable.
For example, the planet could have a subsurface ocean of liquid water, which could potentially support life. Additionally, the planet's nightside is much cooler than its dayside, so it is possible that life could exist in the cooler regions of the planet.
JWST's future observations of TRAPPIST-1 b and other exoplanets will help scientists to better understand the atmospheres of these worlds and to identify potential candidates for life.