Scientists have discovered an Earth-sized planet that could support life

(CNN) —Two teams of scientists have discovered a theoretically habitable planet, smaller than Earth but larger than Venus, orbiting a small star about 40 light-years away.

The exoplanet, called Gliese 12b, orbits a cool red dwarf star located in the constellation Pisces that is about 27% the size of our Sun and 60% the temperature, according to two studies published Thursday in The Astrophysical Journal Letters and Monthly. Notices of the Royal Astronomical Society.

Because its star is much smaller than the Sun, Gliese 12b is still within the habitable zone (the ideal distance for a star where liquid water can exist) even though it completes its orbit every 12.8 days.

Assuming the exoplanet has no atmosphere, scientists calculated its surface temperature to be about 107 degrees Fahrenheit (42 degrees Celsius).

“We have found the closest transitory, temperate, Earth-sized world to date,” said Masayuki Kuzuhara, an assistant professor on the project at the Tokyo Astrobiology Center and co-leader of one of the research teams with Akihiko Fukui, a project associate with Akihiko Fukui. An assistant professor at the University of Tokyo said in a statement.

Once Earth-sized temperate planets are identified, scientists will be able to analyze them to determine what elements are in their atmospheres and, most importantly, whether water is present to support life.

“We’ve only found a handful (of exoplanets) that are good candidates for this. This is the closest and it’s a very important discovery,” Larissa Palethorpe, a PhD student at the University of Edinburgh and University College London, who co-led the other study, told CNN on Friday. “.

Understanding Glees 12b

To detect Gliese 12b, scientists used publicly available data collected by NASA’s Transiting Exoplanet Survey Satellite (TESS), a telescope that monitors tens of thousands of stars each month and tracks their brightness changes, which may be evidence of exoplanets in their orbit. .

It is easier for astronomers to find exoplanets orbiting red dwarf stars, as their relatively small size leads to a greater dimming effect during each transit.

Right now, scientists aren’t sure exactly what makes up the planet’s atmosphere, if any, and whether there’s water, although Palethorpe said they don’t expect to find water there.

“There can be no water,” he said, “and then we will know that runaway global warming has already occurred on this planet, which will make it look more like Venus.” “There could be water, which means it could be more like ours…or there could be signals that could be detectable that could show that runaway global warming is in progress, so you could be losing water.”

For the next stage of analyzing the exoplanet’s atmosphere, scientists hope to use the James Webb Space Telescope and perform spectroscopic analysis. This method involves capturing starlight shining through the atmosphere of an exoplanet and seeing what wavelengths are absorbed by certain molecules, revealing their presence in the atmosphere.

In addition to shedding light on the exoplanet itself, Palethorpe said scientists hope this work will help us better understand our planet.

“What this planet in particular will teach us is what happened so that Earth remained habitable but Venus was not… It can tell us about the habitability paths that planets take as they evolve,” he said.

But even though the exoplanet could be habitable for humans and is relatively “close” to our solar system in astronomical terms, it is unlikely that anyone will visit it anytime soon.

“It’s inaccessible, it’s 12 parsecs away,” Palethorpe said, adding that it would take about 225,000 years to reach Gliese 12b with the fastest spacecraft currently in existence.