Astronomers finally detect a rocky planet with an atmosphere

Astronomers have searched for years for rocky planets beyond our solar system with an atmosphere - a trait considered essential for any possibility of harbouring life.

Astronomers have searched for years for rocky planets beyond our solar system with an atmosphere - a trait considered essential for any possibility of harbouring life. Well, they finally seem to have located one. But this hellish planet - apparently with a surface of molten rock - offers no hope for habitability.

Researchers said on Wednesday the planet is a "super-Earth" - a rocky world significantly larger than our planet but smaller than Neptune - and it orbits perilously close to a star dimmer and slightly less massive than our sun, rapidly completing an orbit every 18 hours or so.

Infrared observations using two instruments aboard the James Webb Space Telescope indicated the presence of a substantial - if inhospitable - atmosphere, perhaps continuously replenished by gases released from a vast ocean of magma.

"The atmosphere is likely rich in carbon dioxide or carbon monoxide, but can also have other gases such as water vapor and sulfur dioxide. The current observations cannot pinpoint the exact atmospheric composition," said planetary scientist Renyu Hu of NASA's 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 that of Venus, whose toxic atmosphere is the densest in our solar system.

The planet, called 55 Cancri e or Janssen, is about 8.8 times more massive than Earth, with a diameter about twice that of our planet. It orbits its star at one-25th the distance between our solar system's innermost planet Mercury and the sun. As a result, its surface temperature is about 3,140 degrees Fahrenheit (1,725 degrees Celsius/2,000 degrees Kelvin).

"Indeed, this is one of the hottest-known rocky exoplanets," said astrophysicist and study co-author Brice-Olivier Demory of the University of Bern's Center for Space and Habitability in Switzerland, using the term for planets beyond our solar system. "There are likely better places for a vacation spot in our galaxy."