NASA has announced that it will contribute an instrument to a European space mission that will explore the atmospheres of planets or exoplanets orbiting stars beyond our Sun for the first time. The instrument will aid the European Space Agency’s (ESA’s) ARIEL or Atmospheric Remote-sensing Infrared Exoplanet Large-survey mission.
NASA’s instrument has been called the CASE or Contribution to ARIEL Spectroscopy of Exoplanets and it will be managed by NASA’s Jet Propulsion Laboratory in Pasadena, California, with JPL astrophysicist Mark Swain as the principal investigator. The ARIEL spacecraft with CASE on board is expected to launch in 2028.
So far, scientists have found more than 4,000 exoplanets in the Milky Way galaxy with the help of NASA’s retired Kepler space telescope and the currently active TESS (Transiting Exoplanet Survey Satellite). The space agency says that ARIEL will take planet-hunting through transits one step further.
NASA says that ARIEL will be able to see the chemical fingerprints, or “spectra,” of a planet’s atmosphere in the light of its star. “The spacecraft will observe starlight streaming through the atmospheres of planets as they pass in front their stars, as well as light emitted by the planets’ atmospheres just before and after they disappear behind their stars,” NASA explains.
The space agency says that these fingerprints will allow scientists to study the compositions, temperatures, and chemical processes in the atmospheres of the planets that ARIEL observes.
The chemical fingerprints of exoplanet atmospheres are extremely faint, so identifying them is a big challenge for astronomers. It requires a telescope to stare at individual stars for a long time and ARIEL will be the first spacecraft fully devoted to the task. It will observe hundreds of exoplanet atmospheres, looking to identify their contents, temperatures and chemical processes.
With the addition of CASE, the ARIEL will be able to observe clouds and hazes as well that will provide a more comprehensive picture of the exoplanet atmospheres. CASE will also allow measurements of each planet’s albedo, the amount of light the planet reflects.