Astronomers detected for the first time an atmosphere around an Earth-like planet other than the Earth.
Dr John Southworth, from the Keele University lead the team that made they discovery. They used the 2.2 m ESO/MPG telescope in Chile to observe the star GJ 1132a and it’s planet.
This made them able to measure the dip in brightness caused by the planet and its atmosphere as it transits in front of the star.
“While this is not the detection of life on another planet, it’s an important step in the right direction: 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 Dr John Southworth.
In the search of life
Currently astronomers look into planets atmosphere and its chemical composition, searching for signs of living organisms. A large amount of oxygen, like the one on Earth, is such a sign.
Before the atmosphere detection at GJ 1132b, the only atmospheres detected were of hot Jupiters.
“With this research, we have taken the first tentative step into studying the atmospheres of smaller, Earth-like, planets. We simulated a range of possible atmospheres for this planet, finding that those rich in water and/or methane would explain the observations of GJ 1132b. The planet is significantly hotter and a bit larger than Earth, so one possibility is that it is a “water world” with an atmosphere of hot steam.” – says Southworth.
Gj 1132b atmosphere
GJ 1132b orbits the small red dwarf GJ 1132, located 39 light years away in the constellation Vela.
The astronomers’ team used the GROND imager of the 2.2 m ESO/MPG telescope located in Chile to observe the planet in as much as seven different wavelengths including the optical and near-infrared. The planet is transiting its star every 1.6 days and does it between the Earth and its host star.
From the drop in brightness caused by the transit, scientists measured the size of the planet at 1.4 times Earth.
The most important of the observations show that the planet appears large in one of the 7 wavelengths measured. This means that the planet has atmosphere that is “blurred” in this specific light, but transparent in all others.
The discovery of such atmosphere means a lot to astronomers.Red dwarfs are one of the most common stars in the universe and are known to host many planets.But because of their variable light and big magnetic activity, they can easily evaporate planet’s atmospheres.
The characteristics that GJ 1132b possess means that its atmosphere will endure for billions years.
This means, given the large numbers of red dwarf stars (they make 3/4 of all stars), that the conditions suitable for life are very common in the universe.
This puts GJ 1132b one of the highest priority targets to study by future telescopes like the James Webb Space Telescope.