“It’s a great proof of concept that we can observe atmospheres on these small, rocky planets even from the ground,” a planetary scientist at Arizona State university who was not involved in the paper Laura Schaefer said this. Astronauts and scientist and researchers have been looking for the planet with same atmospheric conditions as that of the planet Earth since the beginning of time.
As with the depleting atmospheric conditions and increasing population Earth will become too small to live by its inhabitants. So, finally, there is a hope that they have found an alternative for it. Yes, GJ 1132b, just 39 light-years away is that other alternative with almost same atmospheric conditions as the earth. “That’s really exciting and that means that we’ll be able to do it with more planets down the line as we find more planets of this size.” Gliese 1132b was first spotted in 2015 while orbiting a small, dim M dwarf (a type of red dwarf) star about one-quarter of the Sun’s radius. Astronomers have started calling Gliese 1132b super earth. The astronomers often try to find exoplanets by using the transit method which is, they wait for a planet to cross in front of its star and measure how much starlight is blocked. Because of the fact that GJ 1132b is so close, and because its star is so small, the rocky planet blocks proportionally more light, making it easier to study. The exoplanets whose atmospheres have been studied by now are gas-giant planets or very large super-Earths, with something like eight times our planet’s mass but Gliese 1132b is interesting not just because it’s the first low-mass super-Earth to have a detectable atmosphere but because it’s near Earth, putting it in the sights of existing telescopes; and it was also thought to be about 1.2 times the Earth’s radius, making it very close in size and potentially similar composition to our planet Earth. Let us see now that how do the astronomers find about such planets. As a planet passes in front of the star, it blocks a certain amount of starlight across all seven bands of the white light : VIBGYOR. But the small amount of starlight that passes through the atmosphere will be selectively filtered: Certain chemicals in the atmosphere will absorb (and thus, block) certain wavelengths while allowing others to pass straight through it. Then the missing wavelengths tell the scientists which atoms and molecules are present and which ones are absent from it. And here in the case of this planet GJ 1132b it is found out that there is a presence of an atmosphere that is transparent to some wavelengths but opaque to others. The researchers then modeled different scenarios, finding that the atmosphere could potentially be rich in water and methane. And if that is true then the planet could have a steamy atmosphere and perhaps a magma ocean as said by Schaefer who is following up this subject very seriously. But then also, she has pointed out “It’s not confirmed that it’s water”. “So it’s very exciting but we definitely need more data on it.” Also, the recent observations have pointed out that the silhouetted planet has a radius about 1.4 times that of Earth, making it a little bigger than previously thought. The researchers say that these red dwarfs or M-dwarfs are also thought to be much more active than main-sequence stars like the sun with flares, eruptions and other activity that could blow a planet’s atmosphere away completely. Also, these M-dwarfs are thought to offer one of the best chances for finding a life-friendly world. This planet, this super-earth circles its star so closely that its “year” lasts just 1.6 Earth days and so if the planet does turn out to have an atmosphere in spite of that proximity, then it would turn out to be good news for astronomers as it would mean that M dwarfs are more stable places for habitable planets than thought. And with the launch of NASA’s Transiting Exoplanet Survey Satellite (TESS) later this year and the James Webb Space Telescope in 2018, researchers may soon be able to find more interesting nearby targets and then probe their atmospheric composition with precision and find out more exoplanets with life existing on them.