Exoplanets with clouds have been detected using the NASA Hubble Space Telescope, according to a recent study. They represent the two of the Milky Way galaxy’s most common types of planets. The finding of clouds, though, is not necessarily an indication that the planets have water and might also be able to support life.
The NASA Hubble Space Telescope detected two exoplanets with clouds, GJ 436b, in the Leo constellation, 36 light-years in distance away; and, GJ 1214b, first discovered in 2009, in the Ophiuchus constellation, 40 light-years distant from Earth.
Both of the two planets, while bigger than Earth, are not as large as gas giants like Jupiter. GJ 436b is about the size of Neptune, but it is closer to its star than Neptune is to the sun, so it’s been labelled a “warm Neptune.” Because of its comparatively large size, GJ 1214b has been called a “super-Earth.”
Until the two exoplanets were closely examined using Hubble, it was unknown if the planets had clouds, or what the possible composition of the clouds might be.
Laura Kreidberg and Jacob Bean of the University of Chicago led a team of astronomers who used the NASA Hubble Space Telescope to analyze the clouds of GJ1214b, the exoplanet dubbed a super-Earth.Though no super-Earths exist in our solar system, astronomers believe that there might be more super-Earths than any other kind of planet in the Milky Way.
According to the study the astronomers recently published in the British journal Nature (which you can read below by clicking on the last source listed), they found, using the Hubble Spectra data, and measuring the spectrum of GJ 1214b in near-infrared light, that the upper atmosphere clouds which blanket the exoplanet did not contain carbon dioxide, carbon monoxide, water vapor, nitrogen, or methane. The absence of these in the upper atmosphere of GJ 1214b is a possible indication that the exoplanet doesn’t support life.
The study was the largest Hubble program ever devoted to studying a single exoplanet. It took place over the course of 96 hours of telescope observation time, and 11 months, overall.
When this exoplanet was studied in the past, researchers theorized that the clouds could be composed of water vapor or some other type of heavy molecule. The NASA Hubble Space Telescope and the Hubble’s Spectra data has shot down the idea that the clouds in the upper atmosphere of GJ 1214b are composed of water vapor.
What might the clouds detected on the super-Earth, GJ 1214b, be composed of?
According to the study, the clouds might possibly be composed of zinc sulphate, potassium, or chloride. For these elements to make clouds, the temperature would have to be blistering hot, like around 450 degrees Fahrenheit (232 degrees Celsius) on the the surface of GJ 1214b.
The research by the Chicago-based team will, the astronomers hope, lead to the identification of habitable exoplanets in the future.
According to astronomer and third-year grad student, Laura Kreidberg, their work “lays the foundation” so that they, or others, will be better able to study and characterize “other Earths with similar techniques.”
Written by: Douglas Cobb