Rare Discovery: Atmosphere Found in Earth-Like Exoplanet

An international team of scientists has detected the first ever Earth-like planet outside of our solar system containing what appears to be an atmosphere.

The discovery, detailed in a paper published in The Astronomical Journal, is considered to be very significant because it is the first evidence of an atmosphere around an exoplanet that has nearly the same size as Earth.

"This marks the first detection of an atmosphere around a low-mass Super-Earth, in terms of radius and mass the most Earth-like planet around which an atmosphere has yet been detected," the researchers wrote on a press release. "Thus, this is a significant step on the path towards the detection of life on an exoplanet."

This is the first time an atmosphere was detected in an Earth-like planet. Normally, astronomers could detect an atmosphere i Jupiter-like gas giants or larger super-Earths that have about eight times the mass of Earth.

The exoplanet, known as GJ 1132b, orbits the red dwarf star GJ 1132 located in the Southern constellation Vela about 39 light-years away from Earth. Its radius is about 1.4 times that of Earth and has a mass equivalent to 1.6 times of Earth's. Due to its rocky composition and very high temperatures, astronomers previously called it as a potential Venus twin.

The astronomers detected GJ 1132b during its transit, when the planet passes directly in front of its parent star from the Earth's perspective. Using the GROND imager at the 2.2 m ESO/MPG telescope of the European Southern Observatory in Chile, the astronomers observed the transiting planet simultaneously in seven different wavelength bands.

They observed that the planet appear to be larger in one of the infrared wavelengths than the others. This is a strong indication that the exoplanet has an atmosphere that is opaque to specific infrared lights while appearing to be transparent in others. This made GJ 1132b look larger on those specific wavelength bands.

Astronomers believe that GJ 1132b's atmosphere contains mostly of water vapor or methane. Due to this discovery, GJ 1132b is most likely to become a high priority target for further research.