Exoplanets: The search for habitable planets may have just waned

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Searching for planets that could harbor life It has just narrowed significantly.

Scientists have long hoped and theoretical That the most common type of star in our universe – called an M dwarf – could host nearby planets with atmospheres, potentially rich in carbon and ideal for creating life. But in a new study of a world orbiting an M dwarf 66 light-years from Earth, researchers found no indication that such a planet could retain an atmosphere at all.

Without a carbon-rich atmosphere, the planet is unlikely to be hospitable to living organisms. Carbon molecules are, after all, the building blocks of life. The results don’t bode well for other types of planets orbiting M dwarfs, said Michelle Hill, a planetary scientist and doctoral candidate at the University of California, Riverside.

“The pressure from the star’s radiation is enormous, enough to push out the planet’s atmosphere,” Hill said. In a post on the university’s website.

M dwarf stars are known to be fickle, emitting solar flares and raining radiation on nearby celestial bodies.

But for years, it was hoped that the relatively large planets orbiting near M dwarfs could be in Goldilocks’ environment, close enough to their young star to remain warm and large enough to cling to their atmosphere.

according to New studypublished in The Astrophysical Journal Letters.

A similar phenomenon occurs in our solar system: the Earth’s atmosphere is also deteriorating due to eruptions from its nearby star, the Sun. The difference is that Earth has enough volcanic activity and other gas-emitting activity to make up for the loss in the atmosphere and make it barely detectable, according to the research.

However, the dwarf planet M was examined in the study, Giga 1252 BIt would build up initially, “could contain 700 times more carbon than Earth, and would not have an atmosphere,” study co-author and UC Riverside astrophysicist Stephen Kane said in a press release. But then it fades and erodes.

GJ 1252b orbits less than a million miles from its star, called GJ_1252. The study found that the planet experiences extreme daytime temperatures of 2,242 degrees Fahrenheit (1,228 degrees Celsius).

The planet’s existence was first suggested by NASA’s Transiting Exoplanet Reconnaissance Mission, or TESS. Then, astronomers ordered the roughly 17-year-old Spitzer Space Telescope to set its sights on the region in January 2020 — less than 10 days ago. Spitzer is permanently disabled.

The investigation into whether GJ 1252b has an atmosphere was led by astronomer Ian Crossfield at the University of Kansas and involved a group of researchers from the University of California Riverside, NASA’s Jet Propulsion Laboratory, Caltech, University of Maryland, Carnegie Institution for Science, and Max Plank. Institute of Astronomy, McGill University, University of New Mexico, and University of Montreal.

They rummaged through data produced by Spitzer, looking for signatures of emission, or signs that a gas bubble could be enveloping the planet. The telescope picked up the planet as it passed behind its star, Hill said, allowing researchers to “look at starlight as it passes through the planet’s atmosphere,” giving a “spectral signature of the atmosphere” — or lack thereof.

Hill added that she was not shocked because she found no signs of Joe, but was disappointed. It searches for moons and planets in “habitable zones,” and the results make looking at the worlds orbiting around M dwarf stars everywhere less intriguing.

Researchers hope to gain more clarity about these types of planets with the help of the James Webb Space Telescope, the most powerful space telescope to date.

Webb will soon set his sights on TRAPPIST-1 . system“It is also an M dwarf star with a group of rocky planets around it,” Hill noted.

“There is a lot of hope that it will be able to tell us whether or not those planets have atmospheres around them,” she added. “I think M dwarf fans are probably holding their breath right now to see if we can tell if there’s an atmosphere around those planets.”

However, there are still plenty of interesting places to search for habitable worlds. Aside from looking at planets far from M dwarfs that are more likely to retain atmospheres, there are still nearly 1,000 Sun-like stars relatively close to Earth that could have their own planets orbiting within habitable zones, according to UC Riverside’s website on the study. .