Using observations by NASA’s TESS (Transiting Exoplanet Survey Satellite) and many other facilities, two international teams of astronomers have discovered a planet between the sizes of Earth and Venus only 40 light-years away. Multiple factors make it a candidate well-suited for further study using NASA’s James Webb Space Telescope.
Using observations by NASA’s TESS (Transiting Exoplanet Survey Satellite) and many other facilities, two international teams of astronomers have discovered a planet between the sizes of Earth and Venus only 40 light-years away. Multiple factors make it a candidate well-suited for further study using NASA’s James Webb Space Telescope.
TESS stares at a large swath of the sky for about a month at a time, tracking the brightness changes of tens of thousands of stars at intervals ranging from 20 seconds to 30 minutes. Capturing transits—brief, regular dimmings of stars caused by the passage of orbiting worlds—is one of the mission’s primary goals.
« We’ve found the nearest, transiting, temperate, Earth-size world located to date, » said Masayuki Kuzuhara, a project assistant professor at the Astrobiology Center in Tokyo, who co-led one research team with Akihiko Fukui, a project assistant professor at the University of Tokyo. « Although we don’t yet know whether it possesses an atmosphere, we’ve been thinking of it as an exo-Venus, with similar size and energy received from its star as our planetary neighbor in the solar system. »
The host star, called Gliese 12, is a cool red dwarf located almost 40 light-years away in the constellation Pisces. The star is only about 27% of the sun’s size, with about 60% of the sun’s surface temperature. The newly discovered world, named Gliese 12 b, orbits every 12.8 days and is Earth’s size or slightly smaller—comparable to Venus. Assuming it has no atmosphere, the planet has a surface temperature estimated at around 107 degrees Fahrenheit (42 degrees Celsius).
