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Press Conference (7/24/15) - Alan Stern, Slide 4
Release Date: July 24, 2015
Searching for signs of an atmosphere around Pluto's largest moon Charon, New Horizons' Alice instrument observed Charon passing in front of the sun-an event called an occultation-on July 14, 2015. Only a portion of the occultation data has been transmitted to Earth so far; in that limited dataset, an atmosphere has not yet been detected.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute