June 23, 2024


An Australian university student co-led the discovery of an Earth-sized, potentially habitable planet just 40 light-years away.

Shishir Dholakia, a PhD candidate in astrophysics at the University of Southern Queenslandis part of an international team that published the discovery in the Monthly Notices of the Royal Astronomical Society.

He described the “Eureka moment” of finding the planet, which was named Gliese 12b.

“We did back-of-the-envelope calculations,” he said. “We worked out it’s probably Earth-sized, it’s probably moderate, and that it’s really, really close. In the space of a day we were like, ‘Oh, we have to write this up. This is something very cool.’

It can be at the right temperature for liquid water to pool on the surface … [that’s] important because we think planets are potentially habitable if they can have liquid water on them.

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

Gliese 12b is the size of Earth or slightly smaller, like Venus. And its surface temperature is estimated at a balmy 42C.

Its 12-day orbit is around Gliese 12, a cool red dwarf in the constellation Pisces. Gliese 12 is about a quarter of the Sun’s size, with about 60% of its surface temperature.

Dholakia co-led the team – with University of Edinburgh PhD student Larissa Palethorpe – who collaborated with Nasa to confirm the new planet.

“It’s only 40 light-years away, and that may not mean we can actually get to it anytime in the near future, but it does mean we can point the biggest space telescopes in the world at it and understand what its atmosphere is.” . maybe like,” said Dholakia.

It could shed light on our own solar system.

“Earth and Venus are classic examples of how an atmosphere can change the surface of a planet. So Earth is this haven for life as we know it and Venus is hot enough to melt lead on its surface.

“And the difference between these two planets is largely because Venus has a very hostile atmosphere. So we think that this planet, which is right between Earth and Venus in terms of the amount of light it gets from its sun, can actually bridge the gap… and help us understand why Venus and Earth are so different appears to be “

He said he mostly enjoyed the process, although it was “intimidating” at times.

Nasa uses a transiting exoplanet survey satellite – Tess – to observe the brightness changes of tens of thousands of stars to capture “transits” – “brief, frequent dimmings of stars caused by the transit of orbiting worlds”, according to its website .

It’s easier to spot Earth-sized planets orbiting red dwarfs because, as a smaller star, the transit’s obscuration is greater, and the lower mass means the orbiting planet has a greater “wobble” or “reflex motion.” produce in the star.

Nasa said Gliese 12b was a good candidate for further study with the James Webb Space Telescope.

A leading American astronomer has said he is certain there is a new planet lurking even closer to home. The ABC reported Friday that California Institute of Technology professor of planetary astronomy Michael Brown said he doesn’t see how we could have a solar system without Planet Nine“.

For years, he said the peculiar paths of various objects around Neptune showed the pull of another planet – but no one had been able to find it.

In a new study — which has not yet been peer-reviewed — Brown and his team ran simulations and concluded that there was a one-in-a-million chance that Planet Nine wasn’t there.



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