Astronomers have discovered an earth-like planet with an atmosphere, 39 light years away from us. The planet is known by the name “Gliese 1132 b”.
Gliese 1132 b is an exoplanet orbiting a red dwarf star, Gliese 1132, in the constellation Vela. The planet is considered uninhabitable but cool enough to possess an atmosphere. Gliese 1132 b was discovered by the MEarth-South array in Chile.
It has been called “one of the most important planets ever discovered beyond the Solar System”: Due to its relative proximity to Earth, telescopes should be able to determine the composition of its atmosphere, the speed of its winds and the color of its sunsets. This is due in part to the small diameter of its parent star (21% that of the Sun), which increases the effect on the star’s light of its transits. The planet’s diameter is approximately 20% larger than that of the Earth and its mass is estimated at 1.6 times that of Earth, implying that it has an Earth-like rocky composition. Gliese 1132 b orbits its star every 1.6 days at a distance of 1.4 million miles.
The planet receives 19 times more stellar radiation than Earth. The temperature of the top of its atmosphere is estimated at 500 °F. The planet is estimated to be hotter than Venus, as higher temperatures may prevail near the surface. It is possible that one side of the planet is cooler, because it is presumed to be tidally locked due to its proximity to its star; however, under most circumstances where an atmosphere is thick, it would be able to transfer heat to the far side.
In April 2017, an atmosphere was confirmed around Gliese 1132 b. It is the most Earth-like exoplanet to date that is known to have an atmosphere.