Eureka moment as astronomers find new “potentially habitable” Earth-size planet

Cosmos Magazine


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By Cosmos

A new planet described as “earth-sized and temperate” has been discovered by Queensland and UK astronomers.

University of Southern Queensland (UniSQ) Centre for Astrophysics PhD student Shishir Dholakia analysed observation data from NASA’s TESS (Transiting Exoplanet Survey Satellite) and says it reveals “…the nearest transiting, temperate, Earth-sized planet found to date.”

The exoplanet is named Gliese 12 b. It orbits the small but bright and low magnetic activity star Gliese 12.

Their finding is documented in a paper in the Monthly Notices of the Royal Astronomical Society, and a Japanese team has simultaneously released research in the Astrophysical Journal Letters into the same planet saying: “The discovery of a planet similar to Venus around a star in the neighborhood of the Solar System raises hopes that astronomers may someday unlock the secret to why life appeared on Earth.”

But the UniSQ/UK astronomers say the find represents: “…one of the best targets to study whether Earth-like planets orbiting cool stars can retain their atmospheres.”

Above: Shishir Dholakia talks about Gliese 12b (UniSQ edited Andrew Wyrill)

“The moment we were actually looking at this for the first time, it was the eureka moment of, ‘Wow, this could really be something special’,” Dholakia says.

Dholakia and the team at the Centre for Astrophysics investigated further using the UniSQ Mt Kent Observatory and European Space Agency’s CHEOPS satellite.

He co-led a group with University of Edinburgh PhD student Larissa Palethorpe and collaborated with researchers at NASA to confirm this new planet is Earth-sized and temperate.

Nasa image
Image: NASA

“Gliese 12 b could be at the right temperature for liquid water to pool on its surface, and that’s important because we tend to think liquid water is an essential ingredient for life as we know it,” Dholakia says in a news release from UniSQ.

“And so, in this great search for life that we’re undertaking, we want to try and find planets that are potentially habitable, and this could be a good contender.”

The planet is only 40 light-years away, which makes it one of the closest potentially habitable planets to Earth – and means astronomers can point the largest space telescopes in the world at it to better understand it. They were unable to observe if the planet was tide-locked, that is one side always facing a star while the other is cloaked in perpetual darkness

Dholakia said Gliese 12 b could also potentially hold answers as to why the “twin planets” Earth and Venus have such wildly different atmospheres.

“Earth is this haven for life as we know it, but Venus is hot enough to melt lead on its surface. The difference between these two planets is largely because Venus has a very hostile atmosphere,” he said.

“We think that Gliese 12 b, which is right between Earth and Venus in terms of the amount of light that it gets from its Sun, could help us understand why the two turned out to be so different.”

Shishir dholakia unisq. Jpg
Shishir Dholakia (Image: UniSQ)

Dholakia, who first entered into studying astrophysics following a keen interest in astro photography, said the whole process of this discovery and subsequent international collaboration had been an experience unlike any other.

“It’s been very special; it’s been really nice to learn from everyone who has so much more experience than we do.”

Super Earth-size planet with atmosphere

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