Variations in the amount of water ice on Ceres’ surface suggest a seasonal water cycleOPEN ACCESS 

Andrea Raponi, Maria Cristina De Sanctis, Alessandro Frigeri, Eleonora Ammannito, Mauro Ciarniello, Michelangelo Formisano, Jean-Philippe Combe, Gianfranco Magni, Federico Tosi, Filippo Giacomo Carrozzo, Sergio Fonte, Marco Giardino, Steven P. Joy, Carol A. Polanskey, Marc D. Rayman, Fabrizio Capaccioni, Maria Teresa Capria, Andrea Longobardo, Ernesto Palomba, Francesca Zambon, Carol A. Raymond, Christopher T. Russell

Science Advances 14 Mar 2018:
Vol. 4, no. 3, eaao3757
DOI: 10.1126/sciadv.aao3757

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“The dwarf planet Ceres is known to host a considerable amount of water in its interior, and areas of water ice were detected by the Dawn spacecraft on its surface. Moreover, sporadic water and hydroxyl emissions have been observed from space telescopes. We report the detection of water ice in a mid-latitude crater and its unexpected variation with time. The Dawn spectrometer data show a change of water ice signatures over a period of 6 months, which is well modeled as ~2-km2 increase of water ice. The observed increase, coupled with Ceres’ orbital parameters, points to an ongoing process that seems correlated with solar flux. The reported variation on Ceres’ surface indicates that this body is chemically and physically active at the present time.”