World with summer temperatures from Earth 40 light years away

May 23. () –

Astronomers have made the rare and tantalizing discovery of an Earth-like exoplanet 40 light years away that may be a little warmer than our own world.

The potentially habitable planet, called Gliese 12 borbits its host star every 12.8 days, is comparable in size to Venus (making it slightly smaller than Earth), and has an estimated surface temperature of 42 °Ctypical of Earth’s summer and which is lower than most of the 5,000 exoplanets confirmed so far.

However, that assumes it has no atmosphere, which is the crucial next step in determining whether it is habitable. The discovery of the ‘exo-Venus’, by two international teams of astronomers, is published in the journal ‘Monthly Notices of the Royal Astronomical Society’.

“Gliese 12 b represents one of the best targets to study whether Earth-sized planets orbiting cool stars can retain their atmospheres, a crucial step in advancing our understanding of the habitability of planets in our galaxy,” relates it’s a statement Shishir Dholakia, a PhD student at the Center for Astrophysics at the University of Southern Queensland in Australia. She co-led a research team with Larissa Palethorpe, a PhD student at the University of Edinburgh and University College London.

It may have an Earth-like atmosphere, more like that of Venus, which experienced a runaway greenhouse effect that turned it into a 400°C (752°F) hell with no atmosphere, or perhaps a different kind of atmosphere. atmosphere that is not found in our solar system.

Getting an answer is vital because it would reveal whether Gliese 12 b can maintain temperatures suitable for liquid water (and possibly life) to exist on its surface, while also unlocking answers about how and why Earth and Venus evolved so differently.

Gliese 12 b is by no means the first Earth-like exoplanet discovered, but as NASA has said, there are only a handful of worlds like it that deserve a closer look. It has been announced as “the closest transiting, temperate, Earth-sized world located to date” and a potential target for further investigation by the US space agency’s 7.5 billion pound James Webb Space Telescope.

The closest Earth-like exoplanet to us, and possibly the most famous, is Proxima Centauri b, which is just 4 light-years away. However, since it is not a transit world, we still have a lot to learn about it, including whether it has an atmosphere and potential to host life. Most exoplanets are discovered through the transit method, in which a planet passes in front of its star from our point of view, causing a drop in the brightness of the host star.

During a transit, light from the star also passes through an exoplanet’s atmosphere and some wavelengths are absorbed. Different gas molecules absorb different colors, so the transit provides a set of chemical fingerprints that telescopes like the Webb can detect. Gliese 12 b could also be important because it could help reveal whether the majority of stars in our Milky Way, that is, cool stars, They are capable of hosting temperate planets that have atmospheres and are therefore habitable.

“We only know of a handful of temperate Earth-like planets that are close enough to us and meet other criteria needed for this type of study, called transmission spectroscopy, using current facilities,” notes Michael McElwain, a research astrophysicist at Goddard. NASA Space Flight Center in Greenbelt, Maryland, and co-author of the Kuzuhara and Fukui paper.

“To better understand the diversity of atmospheres and the evolutionary outcomes of these planets, we need more examples like Gliese 12 b.” At 40 light years from Earth, Gliese 12 b is approximately the same distance as the TRAPPIST-1 system. It is made up of seven planets, all about the size of Earth and probably rocky, that orbit a red dwarf star.

Three of them are in the habitable zone, but at least two – and probably all – have no atmosphere and are probably arid, ruling out hopes when they were first discovered eight years ago that they could be life-bearing aquatic worlds.