A team of astronomers has detected an atmosphere around super-Earth GJ 1132b. The planet revolves around the red dwarf star GJ 1132 in the constellation Vela Sur, at a distance of 39 light years from us. This discovery marks the first detection of an atmosphere around a planet very similar to Earth that still has an atmosphere; a significant step towards detecting life on an exoplanet.
The experts, from the Max Planck Institute for Astronomy (Germany) together with other researchers, used the 2.2 m telescope of the European Southern Observatory (ESO) / MPG in Chile to take images of the host star of the planet and measured the slight decrease of brightness as the planet and its atmosphere absorbed some of the star’s light, passing directly in front of its host star.
It is the first time that an atmosphere has been detected around a planet so similar to ours, as it has 1.6 Earth masses and its radius is 1.4 radii that of Earth.
The next thing scientists are immersed in in order to find life is
detect the chemical composition of the atmosphere of this planet, in search of certain chemical imbalances such as in our case, the presence of large amounts of oxygen.
Until now, observations of light from the atmospheres of other exoplanets were associated with planets much more massive than Earth; that is, gas giants (similar to our Jupiter) or a great super-earth with more than eight times the mass of our planet. This observation is different: it paves the way for analysis of the atmosphere of smaller, lower-mass planets that are much more similar to Earth in size and mass.
Regarding observation, ESO’s Grond Imager instrument allowed the planet to be examined simultaneously in seven different wavelength bands. GJ 1132b is a planet in transit. Thus, from the perspective of an observer on Earth, the planet passes directly in front of its star every 1.6 days, blocking some of the star’s light.
Regarding the composition of its atmosphere, scientists believe that the atmosphere could be rich in water and methane, something like a ‘water world’ with an atmosphere of hot steam.
The study has been published in The Astronomical Journal.
