NASA’s Webb Telescope, With Key Contributions From JPL, Detects Possible Atmosphere on Rocky Exoplanet

This artist’s concept shows what the exoplanet 55 Cancri e could look like. Observations by NASA’s Webb telescope suggest it may be surrounded by an atmosphere rich in carbon dioxide or carbon monoxide, which could have bubbled up from of an ocean of magma on the planet’s surface. [Credit: NASA, ESA, CSA, Ralf Crawford (STScI)]

In a significant breakthrough, researchers using NASA’s James Webb Space Telescope, including Renyu Hu from the Jet Propulsion Laboratory in Pasadena, as the lead author, and Aaron Bello-Arufe, also from JPL, as a co-author, have potentially detected atmospheric gases surrounding 55 Cancri e, a hot rocky exoplanet located 41 light-years from Earth.

This discovery marks the best evidence to date for the existence of a rocky planet atmosphere outside our solar system.

Hu emphasized the groundbreaking nature of the findings, saying, “Webb is pushing the frontiers of exoplanet characterization to rocky planets. It is truly enabling a new type of science.”

The exoplanet, also known as Janssen, orbits its Sun-like star at a distance of just 1.4 million miles, resulting in a molten surface and likely tidal locking. Previous observations had left the question of whether 55 Cancri e possesses an atmosphere unanswered.

To distinguish between the possibilities of a substantial atmosphere or a bare surface with vaporized rock, the team utilized Webb’s Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI) to measure infrared light emitted by the planet. Bello-Arufe explained that patterns consistent with a volatile-rich atmosphere were observed in the NIRCam data, suggesting the presence of carbon monoxide or carbon dioxide.

The relatively low dayside temperature of around 2,800 degrees Fahrenheit, measured using MIRI data, further indicated the presence of an atmosphere efficiently distributing energy from the dayside to the nightside, according to Hu.

While 55 Cancri e is too hot to be habitable, the researchers believe it could provide valuable insights into the interactions between atmospheres, surfaces, and interiors of rocky planets, potentially shedding light on the early conditions of Earth, Venus, and Mars.

“Ultimately, we want to understand what conditions make it possible for a rocky planet to sustain a gas-rich atmosphere: a key ingredient for a habitable planet,” Hu said.

MIRI, a crucial instrument in this discovery, was developed through a partnership between NASA and the European Space Agency, with JPL leading the U.S. efforts. The MIRI cryocooler development was also led and managed by JPL, in collaboration with Northrop Grumman in Redondo Beach, California, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland.