James Webb has just discovered an Earth-sized planet orbiting within its star’s habitable zone

The James Webb Space Telescope (JWST) has just confirmed the first exoplanet, and surprisingly, it’s almost exactly the size of Earth as it orbits within its star’s habitable zone.

Astronomers have confirmed the existence of an exoplanet for the first time using the new James Webb Telescope, the most powerful space observatory available to us. The planet, officially identified as LHS 475 b, is roughly the same size as our own, with a diameter 99% of that of Earth. An exoplanet is any planet located outside the solar system; In this case, LHS 475 b is relatively nearby, just 41 light-years away, in the constellation Octane.

Thanks to the Near Infrared Spectrometer (NIRSpec) aboard Webb, scientists were able to capture the planet with ease — it was so easy they only needed two transit observations. The so-called transit method consists of observing the star’s brightness, and looking for the slight dimming that could be caused by planets passing in front of the star.

“There is no doubt that the planet exists. Webb’s original data confirm this to be true.” he said in a statementLustig Yeager. “The fact that it’s a small, rocky planet is impressive for the observatory,” Stevenson added.

Webb is the only telescope capable of discerning the atmospheres of Earth-sized exoplanets. By analyzing its transmission spectrum, attempts were made to find out the details of LHS 475 b’s atmosphere, but it was not possible to determine whether it had an atmosphere. The telescope has truly amazing sharpness, however, and studying the atmosphere requires more careful measurements to draw any definitive conclusions.

The team rules out that this exoplanet has a dense, methane-dominated atmosphere, similar to that of Saturn’s moon Titan, although the prospect of it having an atmosphere of pure carbon dioxide is very tempting. The data so far indicates that LHS 475 b is a few hundred degrees warmer than Earth, so if the clouds were revealed, they would look more like Venus, which has a carbon dioxide atmosphere and is shrouded in dense clouds. The researchers hope to make more observations to answer these questions.

“These first observational results from a rocky Earth-sized planet open the door to many future possibilities for studying the atmospheres of rocky planets using Webb,” Mark Clampin saidDirector of the Astrophysics Division at NASA Headquarters in Washington. “Webb brings us closer than ever before to a new understanding of Earth-like worlds beyond our solar system, and the mission is just beginning.”

The research team, led by Kevin Stephenson and Jacob Lustig-Yeger, both of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, chose to observe this target using Webb after carefully reviewing targets of interest from the Transiting Exoplanet Satellite (TESS). Survey satellite) of NASA that hinted at the existence of the planet.

The team’s results were presented at an American Astronomical Society (AAS) press conference on Wednesday, January 11, 2023. You can read a NASA statement Click here.