 "Gliese 12-b")
An Earth-sized, potentially habitable planet has been discovered just 40 light years away, US space agency Nasa has announced.
Named ‘Gliese 12 b’, it is a super Earth exoplanet that orbits a M-type star. It resembles an exo-Venus in size and solar energy absorption.
“We’ve found the nearest, transiting, temperate, Earth-size world located to date,” said Masayuki Kuzuhara, a project assistant professor at the Astrobiology Center in Tokyo, who co-led a research team with Akihiko Fukui, a project assistant professor at the University of Tokyo. The Japanese university claims to have discovered the Earth-sized exoplanet, among others.
Shishir Dholakia, a PhD candidate in astrophysics at the University of Southern Queensland who also claims to have discovered the exoplanet, described it as a ‘Eureka moment!’
While the planet’s atmosphere remains uncertain, its proximity and characteristics make it a promising candidate for habitable planet.
“It could be at the right temperature for liquid water to pool on the surface,” Dholakia said. “And so in this great search for life that we’re undertaking we want to try to find planets that are potentially habitable, and this could be a good contender,” he said.
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What is Gliese 12 b?
Gliese 12 b, about the size of Earth or slightly smaller, orbits a cool red dwarf star, Gliese 12, in the Pisces constellation, said Nasa.
The space agency reported that this star measures only about 27 per cent of the Sun’s size and boasts a surface temperature approximately 60 per cent of that of the Sun. Orbiting around Gliese 12 is the recently identified exoplanet Gliese 12 b, completing its orbit every 12.8 days.
This planet bears a striking resemblance to Earth in terms of size, being comparable to or slightly smaller than Venus. In the absence of an atmosphere, Gliese 12 b is estimated to possess a surface temperature hovering around 107 degrees Fahrenheit (42 degrees Celsius).
Is the new planet habitable?
It is one of the few known rocky planets where humans could theoretically survive, researchers said. The planet receives 1.6 times more energy from its star as Earth does from the sun.
However, the planet’s distance of 40 light years away means it is too far away to experience more closely, researchers at University of Warwick lamented.
An essential element for maintaining an atmosphere is the level of turbulence exhibited by its host star. Red dwarfs often display significant magnetic activity, leading to frequent and potent X-ray flares. Nevertheless, investigations conducted by research teams assert that Gliese 12 exhibits no indications of extreme conditions.
Gliese 12 b is relatively close in astronomical terms, situated merely 40 light years away. However, based on current estimates by researchers, even with our fastest spacecraft, it would require approximately 300,000 years to reach its location.
Significance of Gliese 12 b’s atmosphere
Researchers emphasised the significance of studying Gliese 12b’s atmosphere, noting its potential insights into our solar system’s dynamics. They highlighted the stark differences between Earth and Venus, due to their atmospheres, and expect that studying Gliese 12 b’s will help in bridging that gap.
“Earth remains habitable, but Venus does not due to its complete loss of water. Gliese 12 b’s atmosphere could teach us a lot about the habitability pathways planets take as they develop,” said co-lead of the study Larissa Palethorpe, a doctoral student at the University of Edinburgh and University College London.
How was the new planet discovered?
Nasa’s TESS satellite played a crucial role in the discovery, spotting the planet’s transit and initiating further interest in studying it with the James Webb space telescope.
TESS (Transiting Exoplanet Survey Satellite) is a Nasa astrophysics explorer that is engaged in prolonged observation periods, focusing on extensive portions of the sky for roughly a month each time.
During these observations, it monitors fluctuations in brightness among tens of thousands of stars, with intervals varying from 20 seconds to 30 minutes. A key objective of the mission is to detect transits, which are brief and recurrent dimmings of stars resulting from the transit of orbiting celestial bodies.
