NASA's James Webb telescope confirms its first-ever exoplanet
The James Webb Space Telescope (JWST) has added another feather to its cap. For the first time, observations from JWST have helped researchers confirm the presence of an exoplanet. The "relatively close" alien planet, dubbed LHS 475 b, is similar in size to the Earth and lies only 41 light-years from us, in the constellation Octans.
Why does this story matter?
- JWST has snapped images of exoplanets before but this is the first time that it has identified an exoplanet in another planetary system.
- The $10 billion space observatory headed by NASA, has been providing magnificent insights into the cosmos ever since it began operations.
- Recently, scientists identified a trio of ancient galaxies from Webb's deep-field image, the first-ever picture taken by the telescope.
LHS 475 b takes two days to complete an orbit
Scientists decided to use JWST to peer into this particular exoplanet based on former observations from NASA's Transiting Exoplanet Survey Satellite (TESS). JWST, with the help of its onboard near-infrared spectrograph, was able to capture LHS 475 b as it made transits around its parent star. Researchers identified that the exoplanet completes an orbit in just two days, based on the light curve.
Webb's observations pave the way for studying other exoplanets
"These first observational results from an Earth-size, rocky planet open the door to many future possibilities for studying rocky planet atmospheres with Webb," said Mark Clampin, director of the Astrophysics Division at NASA's Headquarters. "Webb is bringing us closer and closer to a new understanding of Earth-like worlds outside our solar system, and the mission is only just getting started."
LHS 475 b's diameter is 99% of Earth's
A whole new world!— NASA Webb Telescope (@NASAWebb) January 11, 2023
41 light-years away is the small, rocky planet LHS 475 b. At 99% of Earth’s diameter, it’s almost exactly the same size as our home world. This marks the first time researchers have used Webb to confirm an exoplanet. https://t.co/hX8UGXplq2 #AAS241 pic.twitter.com/SDhuZRfcko
Webb can characterize atmospheres of Earth-sized exoplanets
According to NASA, among all the operating (ground and space) telescopes, only Webb can characterize the atmospheres of Earth-sized exoplanets. This brings us to an important question: What sort of an atmosphere if there is one, does this exoplanet behold? We do not know that as yet, but scientists are looking for an answer based on Webb's transmission spectrum.
The exoplanet may lack an atmosphere
While there is no definite conclusion about LHS 475 b's atmosphere, scientists believe that it cannot have a methane-laden atmosphere, like Saturn's moon Titan. There are some atmospheric compositions the team has not ruled out, such as a pure carbon dioxide atmosphere. There's also a possibility that the exoplanet might lack an atmosphere and the researchers will conduct more studies in the coming months.
The exoplanet is warmer than the Earth
Webb's observations also revealed that the exoplanet's temperature is a few hundred degrees warmer than Earth's. And, given that LHS 475 b is closer to its host star than any planet in our solar system, and that its parent star has less than half the temperature of the Sun, researchers believe that this exoplanet might possess an atmosphere, at least theoretically.