What processes are occurring on the much-studied exoplanet, Trappist-1 b, despite it orbiting outside the inner edge of the star’s habitable zone (HZ)? This is what a recent study published in Nature Astronomy hopes to address as an international team of researchers investigated Trappist-1 b’s atmospheric and surface characteristics to ascertain the planet’s present state. This study holds the potential to help researchers develop more efficient methods for studying exoplanets with the goal of determining if they have conditions for life as we know it.
For the study, the researchers used the Mid-Infrared Instrument (MIRI) onboard NASA’s powerful James Webb Space Telescope (JWST) to conduct observations during several occultations of Trappist-1 b, which is when the planet crosses in front of its star, either directly or at an angle. Through this, astronomers can observe the planets’ atmosphere using the starlight shining through it, thus gaining greater insight into the atmospheric composition.
After collecting heat signature data, the researchers came to two plausible conclusions: Trappist-1 b lacks an atmosphere entirely whose surface is comprised of recent geological activity, or Trappist-1 b is comprised of a thick, pure-carbon dioxide atmosphere that exhibits hazes like Saturn’s moon, Titan.
Going forward, the team aspires to conduct what’s called a phase curve observation of Trappist-1 b, which is when astronomers measure changes in brightness as the planet orbits its star. In this case, the team will obtain measurements when Trappist-1 b is directly in front of its star, right before it passes behind its star, and just after it emerges from behind its star. Through this, the team will be able to ascertain the surface heat distribution on Trappist-1 b and put tighter constraints on its atmospheric and surface compositions.
What new discoveries about Trappist-1 b will researchers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Nature Astronomy, EurekAlert!, Max Planck Institute for Astronomy
Featured Image: Artist’s rendition of Trappist-1 b orbiting its star. (Credit: Thomas Müller (HdA/MPIA))
