Astronomers have finally found an Earth-like planet that also has an atmosphere. Why 55 Cancers can’t be inhabited

Astronomers have been searching for many years for telluric planets outside our solar system that have an atmosphere – a characteristic considered essential to be able to host life. Well, it looks like they’ve finally found one, only this hellish planet – apparently with a surface made of molten rock – doesn’t offer any hope of being habitable.

Researchers announced on Wednesday that this planet is a “super-Terra” – a telluric world significantly larger than our planet but smaller than Neptune – and that it orbits dangerously close to its star – less bright and less massive than the Sun ours – completing one orbit in just 18 hours.

Infrared observations made with two instruments aboard the James Webb Space Telescope indicated the presence of a substantial—if inhospitable—atmosphere, likely fed continuously by gases released by a vast ocean of magma.

“The atmosphere is probably rich in carbon dioxide or carbon monoxide, but it may also have other gases, such as water vapor and sulfur dioxide. Current observations cannot specify the exact composition of the atmosphere,” said Renyu Hu, planetary scientist at NASA’s Jet Propulsion Laboratory and Caltech, the lead author of the study published in the journal Nature, according to Reuters, taken over by Agerpres.

Also, the data obtained with the help of the James Webb space telescope did not clarify the thickness of the atmosphere. Renyu Hu said it could be as thick as Earth or even thicker than Venus, whose toxic atmosphere is the densest in our solar system.

How hot is 55 Cancers

That exoplanet, 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 a distance 25 times smaller than the distance between Mercury and the Sun. As a result, the temperature at its surface is approximately 1,725 ​​degrees Celsius.

“Indeed, this is one of the hottest telluric exoplanets known,” 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 in outside our solar system.

“There are probably better places for a vacation destination in our galaxy,” he added.

The exoplanet most likely evolves in synchronous rotation, which means that it is always with the same side facing its star, just as the Moon is in relation to the Earth. The planet is located in our galaxy, the Milky Way, about 41 light-years from Earth, in the constellation Cancer.

A light-year represents the distance traveled by light in a calendar year, i.e. 9,500 billion kilometers. Four other planets, all gas giants, are known to orbit the same host star.

That star is gravitationally bound to another star in a binary system. The other star is a red dwarf, the smallest type of ordinary star. The distance between the two stars is 1,000 times greater than the distance between Earth and the Sun, and light takes six days to travel from one to the other.

“The planet is uninhabitable”

After so much searching, the telluric exoplanet for which scientists finally found evidence of an atmosphere turned out to be one that probably shouldn’t even have an atmosphere. Being so close to its star, any atmosphere should be destroyed by solar radiation and solar winds. But gases dissolved in the vast lava ocean believed to cover the exoplanet’s surface could continue to be emitted by that magma and rebuild the atmosphere, Renyu Hu said.

“The planet is uninhabitable,” said the same researcher, because it is too hot to contain liquid water, considered a prerequisite for sustaining life.

All previously discovered exoplanets that have atmospheres are gas planets, not telluric planets. As the James Webb Space Telescope pushes the frontiers of exoplanet exploration, the discovery of a telluric planet with an atmosphere still represents progress.

On Earth, the atmosphere warms the planet, contains the oxygen that humans breathe, protects against solar radiation, and creates the pressure necessary for liquid water to remain on the planet’s surface.

“On Earth, the atmosphere is essential for life,” said Brice-Olivier Demory.

“This result obtained with 55 Cancri e raises the hope that the James Webb telescope could carry out similar investigations on planets that are much cooler than 55 Cancri e and which may have liquid water on their surface. But we are not there yet,” he added.

Publisher: BP

Download the Digi24 app and find out the most important news of the day