First-Ever Atmosphere Detected on Rocky Exoplanet 55 Cancri e

Using the James Webb Space Telescope (JWST), astronomers have detected for the first time that a rocky planet outside our solar system has an atmosphere. Although the planet may be covered in a magma ocean and therefore unable to support life as we know it, scientists think it may reveal clues about Earth's early history - after all, Earth was once a molten, rocky planet.

The discovery marks an important milestone in exoplanet research. Earth's thin atmosphere is crucial to sustaining life, and the discovery of atmospheres on similar Earth-like planets is an important step in the search for life outside the solar system.

The planet, called 55 Cancri e, orbits a sun-like star. It is considered a super-Earth, a terrestrial planet slightly larger than Earth - its radius is about twice that of Earth and its mass is more than eight times that of Earth. Its atmosphere may be rich in carbon dioxide or carbon monoxide and be "up to a few percent of the planet's radius" thick, according to a paper published in the journal Nature.

Before the recent observations, astronomers had revised their view of 55 Cancri e several times. The planet was discovered in 2004, and initially, researchers thought it might be the core of a gas giant similar to Jupiter. But in 2011, after observations from the Spitzer Space Telescope showed the planet passing by its star, researchers discovered that 55 Cancri e was, in fact, much smaller and denser than the gas giant, and it was confirmed as a super-Earth.