Earlier this month, scientists discovered the existence of an atmosphere on an exoplanet much like Earth, making this the first Earth-like exoplanet with atmosphere to have been detected aside from earth itself. The planet is named GJ 1132b, located in the constellation Vela as a planet of the low-mass star GJ 1132. The planet is located approximately 39 lightyears away from Earth.
The planet’s atmosphere was discovered by professor at Keele University, Dr. John Southworth at the 2.2m ESO/MPG telescope in Chile during routine observations of the planet’s host star, GJ 1132. Upon transit of the planet across the star, they noticed a slight dimming of the planet, which they attributed to the absorption of the starlight by the planet’s atmosphere. Based on simulations of possible fitting atmospheres for the planet, an atmosphere composed of water or methane would explain the specific dimming caused during transit. Since the planet has been seen to be significantly hotter and larger than Earth, the possibility that the planet is some sort of “water world” with a hot steam atmosphere is highly likely.
The discovery of an atmosphere on GJ 1132b aids greatly in the search for life, as the current strategy for doing so often involves analysis of the chemical compositions of different exoplanets’ atmospheres to look for signs of chemical imbalances that could be caused by living organisms, such as the high concentration of oxygen on Earth.
For more detail on the specific observations and calculations, read on here.