by Scientists have discovered a new Earth-like planet that could support alien life – just 40 light years away.
The planet is a great discovery in the search for a habitable world: it is slightly smaller than Earth, and is thought to be slightly warmer. Many planets outside our solar system, known as exoplanets, are usually much larger and hotter than our own.
The newly discovered planet is called Gliese 12b and researchers say that even if we can’t find out if alien life exists, it will help our search for other possible lives.
The planet orbits its host star every 12.8 days, and is comparable in size to Venus – so slightly smaller than Earth.
It has an estimated surface temperature of 42C, which is lower than most of the 5,000-odd exoplanets (planets outside the solar system) confirmed so far.
Astronomers suggest that Gliese 12 b is one of the few known planets where humans could theoretically live, but they are still not sure what its atmosphere looks like, if it has one at all.
Getting an answer to what the atmosphere looks like is crucial because it would indicate whether the planet can maintain temperatures suitable for liquid water – and possibly life – to exist on its surface.
Masayuki Kuzuhara, project assistant professor at the Center for Astrobiology in Tokyo, who led one research team with Akhiko Fukui, said: “We have found the closest, transiting, moderate, Earth-sized world to date.
“Although we still don’t know if it has an atmosphere, we were thinking of it as an exo-Venus, which has the same size and energy received from its star as our planetary neighbor in the solar system.”
Professor Thomas Wilson, a University of Warwick physicist, was involved in the discovery, using data from NASA satellites to confirm the planet’s existence and characteristics such as its size, temperature and distance from Earth.
He said: “This is a very exciting discovery and will help our research on Earth-like planets.
“Sadly, this planet is a bit too far for us to experience it more closely. The light we see now is 40 years ago – that’s how far it took us to get here on Earth.
“There are very few planets like Gliese 12 b, so it’s very rare that we’ll be able to examine one closely and learn about its atmosphere and temperature.”
Both teams, including one in Tokyo, used observations from NASA’s TESS (Transiting Exoplanet Survey Satellite) to aid in their discovery.
The planet’s counterpart, the Sun, known as Gliese 12, is a cool red dwarf located in the constellation Pisces.
The star is only about 27% the size of the Sun, and about 60% the temperature of the Sun’s surface.
Gliese 12 b isn’t the first Earth-like exoplanet to be discovered, but NASA said it’s only a handful of worlds like it that would warrant a closer look.
It has been billed as a potential target for further investigation by the US space agency’s £7.5 billion James Webb Space Telescope.
The newly discovered planet could also be significant because it could help determine whether the majority of stars in the Milky Way galaxy are capable of producing temperate planets with atmospheres that are therefore habitable.
Only 7% of the distance between the Earth and the Sun separates the planet from its star, and the planet receives 1.6 times more energy from its star than the Earth receives from the Sun.
One important factor in maintaining an atmosphere is the stellar storm.
Red dwarfs are usually magnetically active, resulting in powerful X-ray flares.
However, scientists’ analyzes conclude that Gliese 12 shows no signs of extreme behavior.
“Gliese 12 b represents one of the best targets for studying whether Earth-sized planets orbiting cool stars can retain their atmospheres, a critical step in our understanding of planetary habitation throughout our promote a galaxy,” said Shishir Dholakia, a doctoral student at the Centre. Center for Astrophysics at the University of Southern Queensland in Australia.
He led a research team with Larissa Palethorpe, a doctoral student at the University of Edinburgh and University College London (UCL).
Co-author Dr Vincent Van Eylen, also from UCL, said: “GJ12b is a very exciting planet because it is the size of the Earth.
“Although GJ12b is about 15 times closer to its star than Earth is to our Sun, because it orbits such a small star the temperature on the planet can be quite similar to that on Earth.
“That doesn’t necessarily guarantee the planet is habitable, but it’s a great place to start looking.
“Fortunately it’s also a nearby star, so we’ll learn a lot more about the planet and its atmosphere with telescopes like JWST in the coming years.”
A paper led by researchers in Tokyo is published in The Astrophysical Journal Letters, and Dholakia and Palethorpe’s findings are published in the Monthly Notices of the Royal Astronomical Society.
Additional reporting from agencies
