2024-01-25 19:30:15
Photo from the Hubble Space Telescope, provided by NASA on February 13, 1997 (AFP / NASA)
The Hubble Space Telescope has observed the smallest known planet outside the solar system to contain water in its atmosphere, the American (NASA) and European (ESA) space agencies announced Thursday.
“Water on such a small planet is a landmark discovery,” said Laura Kreidberg of the Max Planck Institute for Astronomy in Germany, co-director of the research. “This brings us closer than ever to describing truly Earth-like worlds.”
The planet in question, GJ 9827d, whose diameter is approximately twice that of Earth, is located in the constellation Pisces, 97 light years away, or more than 900,000 billion km, according to a press release from NASA and the ESA.
These officials believe the planet is either a “mini-Neptune” — with a hydrogen-rich, water-laden atmosphere — or a hotter version of Jupiter’s moon, Europa, which contains twice as much water. than the Earth under its crust.
“GJ 9827d could be half water and half rock,” explained Björn Benneke of the University of Montreal, who co-led the research. “There would be a lot of water vapor on smaller clumps of rock.”
“Until now, we have not been able to directly detect the atmosphere of such a small planet. And we are gradually getting there,” he added.
For three years, Hubble was able to analyze the wavelengths of colors in the atmosphere of GJ 9827d, when light from the star around which it orbits filtered through its atmosphere, and detect the presence of water molecules .
Even though this planet has a water-rich atmosphere, its temperature of 425°C makes it uninhabitable.
This discovery, however, paves the way for other studies of GJ 9827d and similar planets, notably via the James Webb Space Telescope, which can use its high-resolution infrared images to search for other atmospheric molecules such as carbon dioxide and carbon dioxide. methane.
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