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Hubble Telescope spies extremely cloudy exoplanet

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Lisa Winter

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217 Hubble Telescope spies extremely cloudy exoplanet
NASA, ESA, & G. Bacon/STScI, STScI-PRC14-06

For nearly a year astronomers used the Hubble Space Telescope to study GJ 1214b, a “super-Earth” exoplanet that is located about 42 light years away in the Ophiuchus constellation. These observations have allowed scientists to describe the atmosphere, and for GJ 1214b the forecast is extremely cloudy. The results come from a team of astronomers led by Laura Kreidberg and Jacob Bean from the University of Chicago and were published in Nature.

This is the first time scientists have been able to study the atmosphere of a super-Earth, and the accuracy of the cloudy description has been described as having “exquisite precision.” There are two possibilities to explain the cloudiness. The clouds may just be really high in the atmosphere and are obscuring actual conditions on the surface. These clouds would be mostly composed of hydrogen. The second option is a bit more exciting, and could indicate a great deal of water vapor in the atmosphere. The team did not detect any evidence that atmospheric chemicals like methane, carbon dioxide, and nitrogen are present in the atmosphere. Without these, there is no evidence that the atmosphere is cloudless. If the clouds are made of water, they completely dominate the atmosphere.


Despite the fact that Hubble was never designed to observe atmospheric conditions of exoplanets, the team was able to get good results. The James Webb Space Telescope (JWST) that is set to launch in 2018 will be able to more closely examine the atmosphere to determine the composition of the planet and its atmosphere. There has been considerable speculation about its composition

The MEarth Project, which observes red dwarfs and their exoplanets, discovered GJ 1214b in 2009. Though it is much larger than Earth, it is smaller than Neptune, which classifies it as a “super-Earth.” Out of all of the exoplanets in this size range that have been discovered so far, this is by far the easiest to observe. It passes by its parent star every 38 hours, giving scientists frequent opportunities to observe the near-infrared spectrum from the planet, which they can use to discern characteristics. However, until the JWST is operational and can get a closer look at the planet, there will still be considerable speculation about the composition of GJ 1214b.


spaceSpace and Physics
  • tag
  • exoplanets,

  • atmosphere,

  • superEarth,

  • clouds