Scientists have discovered that an Earth-sized planet outside our solar system has its own atmosphere.

It is the first such discovery around a low-mass rocky planet, marking an important step in our understanding of the potential for life on other worlds.

"The detection of an atmosphere around the super-Earth GJ 1132b marks the first time that an atmosphere has been detected around an Earth-like planet other than Earth itself," said lead author John Southworth from Keele University in England, whose research was published in The Astronomical Journal.

The planet, which is 1.4 times the diameter of Earth and 1.6 times its mass, is orbiting a red dwarf star just 12 parsecs, or 39 light years, away.