An illustration of the exoplanet Gliese 12b, orbiting a cool red dwarf star 40 light-years from Earth
NASA/JPL-Caltech/R. Hurt (Caltech-IPAC)
Astronomers have discovered an Earth-like exoplanet just 40 light-years away from our solar system, making it the closest habitable world yet to humans.
The planet, which orbits Gliese 12 in the constellation Pisces, was first discovered by astronomers using NASA’s Transiting Exoplanet Survey satellite, a space telescope.
“It was identified as an ideal candidate for follow-up analysis.” Larissa Palethorpe At the University of Edinburgh, UK.
Palethorpe and his colleagues decided to take a closer look at the planet, which they’ve named Gliese 12b, using the European Space Agency’s Exoplanet Characterization Satellite and ground-based observatories in Australia, Chile, and China.
By observing how the brightness of the star changes as the planet moves around it, the team discovered that Gliese 12b has a fast orbit, completing an orbit around Gliese 12 in just 12.8 days. It is also slightly smaller than Earth and similar in size to Venus. With an estimated surface temperature of 42 °C (108 °F), the planet could potentially support liquid water and even life.
“We’re really excited about this,” Palethorpe said, “because this is the closest transiting temperate planet to Earth, and it’s going to be really important for us to be able to do follow-up observations of its atmosphere with the James Webb Space Telescope.”
To get a better idea of the planet’s habitability, researchers plan to continue monitoring Gliese 12b to determine whether it has an atmosphere, and what kind of atmosphere it has.
“It could be shaped like Earth, it could have a runaway atmosphere like Venus, or it could be anything in between,” Palethorpe said. “We don’t know for sure yet.”
Their findings could help us understand how the rocky planets of our solar system have changed over time: “Whatever the outcome, it could tell us how Earth became habitable and why Venus did not.”
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