Reutersi Reuters https://revistaplaneta.com.br/autor/reuters/
05/09/2024 – 14:42
WASHINGTON (Reuters) – For years astronomers have searched for rocky planets beyond our solar system with an atmosphere — a feature considered essential to any possibility of harboring life. Well, they finally seem to have found one. But this hellish planet—apparently bearing a surface of molten rock—offers no hope of habitability.
Researchers said on Wednesday that the planet is a “super-Earth”, a rocky world significantly larger than our planet but smaller than Neptune, which orbits dangerously close to a fainter star with a mass slightly less than that of Neptune. our Sun, completing one revolution approximately every 18 hours.
Infrared observations using two instruments on the James Webb Space Telescope indicated the presence of a substantial—if inhospitable—atmosphere, perhaps continually fueled by gases released from a vast ocean of magma.
“The atmosphere is probably rich in carbon dioxide or carbon monoxide, but may also have other gases such as water vapor and sulfur dioxide. Current observations cannot pinpoint the exact composition of the atmosphere,” said planetary scientist Renyu Hu, from the NASA Jet Propulsion Laboratory and Caltech, lead author of the study published in the journal Nature.
The Webb data also did not make clear the thickness of the atmosphere. Hu said it could be as thick as Earth’s or even thicker than Venus, whose toxic atmosphere is the densest in our solar system.
Called 55 Cancri e or Janssen, the planet is about 8.8 times more massive than Earth, with approximately twice the diameter of our planet. It orbits its star 1/25th the distance between the innermost planet in our solar system — Mercury — and the sun. And therefore, the temperature on the surface is around 1,725 degrees Celsius.
“In fact, this is one of the hottest rocky exoplanets we know of,” said astrophysicist and study co-author Brice-Olivier Demory of the Center for Space and Habitability at the University of Bern in Switzerland, using the term for planets. that are beyond our solar system.
“There are probably better places to vacation in our galaxy.”
The planet is likely tidally locked, meaning it perpetually faces the same side toward its star, much like the moon does toward Earth. The planet is in our Milky Way galaxy, about 41 light years from Earth, in the constellation Cancer. A light year is the distance that light travels in one year, 9.5 trillion km. Four other planets, all giant and gaseous, orbit their host star as far as we know.
After so much searching, the rocky exoplanet where scientists finally found evidence of an atmosphere turned out to be one that probably shouldn’t have one. Located so close to its star, any atmosphere should be stripped away by irradiation and stellar winds. But gases dissolved in the vast ocean of lava that would otherwise cover the planet could continue to bubble up to replenish the atmosphere, Hu said.
“The planet cannot be habitable,” Hu said, because it is too hot to have liquid water, considered a prerequisite for life.
All previously found exoplanets with atmospheres were gas planets, not rocky ones. With the Webb Telescope pushing the boundaries of exoplanet exploration, the discovery of a rocky one with an atmosphere represents progress.
On Earth, the atmosphere warms the planet, contains oxygen that people breathe, protects against solar radiation, and creates the pressure necessary for liquid water to remain on the planet’s surface.
(Reporting by Will Dunham)
