Since the 1990’s, astronomers have discovered around two thousand planets located outside of our solar system, including gas giants, icy planets, and rocky worlds, most of which are orbiting outside of their parent star’s habitable zone. Of chief interest for exoplanet hunters, however, are those rocky planets that are roughly the same size as Earth, and whose temperatures are neither too hot nor too cold, but just right in order to support liquid water oceans, and therefore possibly life. Unfortunately, to date most of the rocky exoplanets that have been found have surface temperatures far too hot to retain any kind of atmosphere.
That is why the recent discovery of a rocky planet called Gliese 1132b (GJ 1132b) located just 39 light-years away has been greeted with a great deal of excitement by scientists. Not only is GJ 1132b only 1.2 times the size of our Earth, but its temperature of 450 degrees Fahrenheit (232 degrees Celsius), whilst too hot to support life, still allows for the presence of an atmosphere. Commenting on the exciting discovery, David Charbonneau of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts, explained:
“Our ultimate goal is to find a twin Earth, but along the way we’ve found a twin Venus. We suspect it will have a Venus-like atmosphere too, and if it does we can’t wait to get a whiff.”
GJ 1132b circles a red dwarf star (GJ 1132) which is just 20% the size of our Sun, and emits around 0.5% as much light. However, GJ 1132b is located at a distance of just 1.4 million miles, helping to explain its oven like heat, albeit vastly cooler than the 2,000 degrees Fahrenheit (1,100 degrees Celsius) or more temperature so far discovered on other rocky planets. Explaining the significance of the find, Berta-Thompson said:
“We think it’s the first opportunity we have to point our telescopes at a rocky exoplanet and get that kind of detail, to be able to measure the color of its sunset, or the speed of its winds, and really learn how rocky planets work out there in the universe. Those will be exciting observations to make.”