Scientists have announced the discovery of the very first exoplanet found using NASA’s James Webb Space Telescope. The rocky world orbits an alien red dwarf star so tightly that it completes a full circuit once every two Earth-days.
Earth, unique as it is, is but one of the tens of billions of planets that are thought to populate the Milky Way galaxy. The worlds that exist outside of our solar system, orbiting alien stars, are known as exoplanets.
With the help of powerful modern-day telescopes, astronomers have been able to confirm the existence of over 5,000 alien worlds, each of which boasts its own unique and sometimes shockingly alien characteristics.
Incredible James Webb Space Telescope Images
Now, astronomers have made the first confirmed discovery of a new exoplanet using the keen golden eye of the JWST.
The candidate world – known as LHS 475 b – was first identified by NASA’s Transiting Exoplanet Survey Satellite (TESS). TESS was designed to take in a wide-angle view of the cosmos in order to watch out for tiny, periodic dips in the light of distant stars that could indicate the presence of an orbiting exoplanet passing between the telescope and its stellar guardian.
One such light signature was detected from a red dwarf star orbiting within the Milky Way 41 light-years from Earth in the constellation Octans. Following the initial discovery, the JWST was tasked to observe the distant star on August 31 last year.
The initial results from the flagship telescope confirmed the presence of a rocky exoplanet with a diameter 99% that of Earth, in orbit around the red dwarf. The frequency of the light dips from the parent star also revealed that LHS 475 b travels around its star in an incredibly tight orbit – closer even than the path that the innermost planet of our solar system, Mercury, treads around our Sun.
It’s orbit is so close that the planet is able to complete a full circuit of its relatively cool parent star once every two Earth-days.
Despite the quality of the JWST data, the team aren’t yet sure whether or not the newfound world plays host to an atmosphere. However, the scientists have been able to rule out the presence of certain elements, including methane.
“The observatory’s data are beautiful,” explained astrophysicist Erin May, of the Johns Hopkins University Applied Physics Laboratory in a NASA statement. “The telescope is so sensitive that it can easily detect a range of molecules, but we can’t yet make any definitive conclusions about the planet’s atmosphere.”
It is still possible that the world hosts a compact atmosphere made up entirely of carbon dioxide. Such an atmosphere would be difficult to detect, but the resulting greenhouse effect would help explain why the planet is hundreds of degrees hotter than Earth despite the fact that it orbits a star that is half the temperature of the Sun.
By studying distant the worlds orbiting distant stars, astronomers can reveal the secrets of how the planets of our solar system, and those spread throughout the cosmos came to form, and evolve. However, the holy grail of exoplanet exploration would be the discovery of a world that orbits in a star’s habitable zone – the region wherein liquid water is able to exist on a planet’s surface – that has the correct ingredients for the evolution of extra-terrestrial life.
The JWST’s ability to characterise exoplanet atmospheres and search for potential signs of life represents a powerful tool in humanity’s ongoing mission to explore strange new worlds, and ultimately shed light on the question as to whether humanity is alone in the universe.
“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 the NASA Headquarters in Washington. “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.”