Exposed water ice on the nucleus of comet 67P/Churyumov–Gerasimenko

  title={Exposed water ice on the nucleus of comet 67P/Churyumov–Gerasimenko},
  author={Gianrico Filacchione and Maria Cristina De Sanctis and Fabrizio Capaccioni and Andrea Raponi and Francesca Tosi and Mauro Ciarniello and Priscilla Cerroni and Giuseppe Piccioni and Maria Teresa Capria and Ernesto Palomba and Giancarlo Bellucci and St{\'e}phane Erard and Dominique Bockel{\'e}e-Morvan and C{\'e}dric Leyrat and Gabriele Arnold and M. A. Barucci and Marcello Fulchignoni and Bernard Schmitt and Eric Quirico and Ralf Jaumann and Katrin Stephan and Andrea Longobardo and Vito Mennella and Alessandra Migliorini and Eleonora Ammannito and Johannes Benkhoff and J. P. Bibring and Armando Blanco and Maria I. Blecka and Robert Carlson and Uri Carsenty and L. Colangeli and Michel Combes and Michael R. Combi and Jacques Crovisier and Pierre Drossart and Th{\'e}r{\`e}se Encrenaz and Costanzo Federico and Uwe Fink and Sergio Fonti and Wing-H. Ip and P. G. J. Irwin and E. Kuehrt and Yves Langevin and Gianfranco Magni and Thomas B. McCord and Liubov Moroz and Stefano Mottola and Vincenzo Orofino and Ulrich Schade and Fredric W. Taylor and Didier Tiphène and Gian Paolo Tozzi and Pierre Beck and Nicolas Biver and Lydie Bonal and J-Ph. Combe and Daniela Despan and Enrico Flamini and Michelangelo Formisano and Sonia Fornasier and Alessandro Frigeri and Davide Grassi and Murthy S. Gudipati and David Kappel and Francesca Mancarella and Kathrin Markus and Fr{\'e}d{\'e}ric Merlin and Roberto Orosei and G Rinaldi and Marco Cartacci and Andrea Cicchetti and Stefano Giuppi and Yann Hello and Florence Henry and Sophie Jacquinod and J-M Reess and Raffaella Noschese and R. Politi and Gisbert Peter},
Although water vapour is the main species observed in the coma of comet 67P/Churyumov–Gerasimenko and water is the major constituent of cometary nuclei, limited evidence for exposed water-ice regions on the surface of the nucleus has been found so far. The absence of large regions of exposed water ice seems a common finding on the surfaces of many of the comets observed so far. The nucleus of 67P/Churyumov–Gerasimenko appears to be fairly uniformly coated with dark, dehydrated, refractory and… 

Seasonal exposure of carbon dioxide ice on the nucleus of comet 67P/Churyumov-Gerasimenko

The infrared spectroscopic identification of a CO2 ice–rich surface area located in the Anhur region of comet 67P/Churyumov-Gerasimenko is reported, interpreted as the result of the extreme seasonal changes induced by the rotation and orbit of the comet.

Seasonal mass transfer on the nucleus of comet 67P/Chuyumov–Gerasimenko

We collect observational evidence that supports the scheme of mass transfer on the nucleus of comet 67P/Churyumov-Gerasimenko. The obliquity of the rotation axis of 67P causes strong seasonal

Long-term survival of surface water ice on comet 67P

Numerous water-ice-rich deposits surviving more than several months on comet 67P/Churyumov-Gerasimenko were observed during the Rosetta mission. We announce the first-time detection of water-ice

The temporal evolution of exposed water ice-rich areas on the surface of 67P/Churyumov-Gerasimenko: spectral analysis

Water ice-rich patches have been detected on the surface of comet 67P/Churyumov-Gerasimenko by the VIRTIS hyperspectral imager on-board the Rosetta spacecraft, since the orbital insertion in late

Comet nuclei composition and evolution

Thanks to Rosetta orbiter’s and Philae lander’s data our knowledge of cometary nuclei composition has experienced a great advancement. The properties of 67P/Churyumov-Gerasimenko nucleus are

Thermal modelling of water activity on comet 67P/Churyumov-Gerasimenko with global dust mantle and plural dust-to-ice ratio

We perform a thermo-physical analysis on water activity of comet 67P/Churyumov-Gerasimenko (67P). The sublimation of water is assumed to occur from beneath a global, desiccated dust mantle over the

The Philae lander reveals low-strength primitive ice inside cometary boulders.

An investigation of the previously undiscovered site of the second touchdown, where Philae spent almost two minutes of its cross-comet journey, producing four distinct surface contacts on two adjoining cometary boulders, provides constraints for cometary landers seeking access to a volatile-rich ice sample.

An orbital water-ice cycle on comet 67P from colour changes

Spectral analysis of the VIRTIS dataset shows two opposite seasonal colour cycles in the coma and on the surface of comet 67P/Churyumov–Gerasimenko, indicating an orbital water-ice cycle.

Comet 67P/CG Nucleus Composition and Comparison to Other Comets

We review our current knowledge of comet 67P/Churyumov–Gerasimenko nucleus composition as inferred from measurements made by remote sensing and in-situ instruments aboard Rosetta orbiter and Philae

Comet 67P/CG Nucleus Composition and Comparison to Other Comets

We review our current knowledge of comet 67P/Churyumov–Gerasimenko nucleus composition as inferred from measurements made by remote sensing and in-situ instruments aboard Rosetta orbiter and Philae



The diurnal cycle of water ice on comet 67P/Churyumov–Gerasimenko

Observations of water ice on the surface of comet 67P/Churyumov–Gerasimenko are reported, appearing and disappearing in a cyclic pattern that follows local illumination conditions, providing a source of localized activity.

The organic-rich surface of comet 67P/Churyumov-Gerasimenko as seen by VIRTIS/Rosetta

The VIRTIS instrument on board the Rosetta spacecraft has provided evidence of carbon-bearing compounds on the nucleus of the comet 67P/Churyumov-Gerasimenko, and no ice-rich patches are observed, indicating a generally dehydrated nature for the surface currently illuminated by the Sun.

Subsurface properties and early activity of comet 67P/Churyumov-Gerasimenko

Subsurface temperatures showed seasonal and diurnal variations, which indicated that the submillimeter radiation originated at depths comparable to the diurnal thermal skin depth of comet 67P/Churyumov-Gerasimenko.

Exposed Water Ice Deposits on the Surface of Comet 9P/Tempel 1

The direct detection of solid water ice deposits exposed on the surface of comet 9P/Tempel 1, as observed by the Deep Impact mission, suggests that the surface deposits are loose aggregates.

Comet 46P/Wirtanen: Evolution of the subsurface layer

Abstract Cometary nuclei are composed mostly of water ice and mineral grains. When a comet passes near the Sun, volatiles sublimate. This process leads to the formation of a dust layer covering the

OSIRIS observations of meter-sized exposures of H2O ice at the surface of 67P/Churyumov-Gerasimenko and interpretation using laboratory experiments

Since OSIRIS started acquiring high-resolution observations of the surface of the nucleus of comet 67P/Churyumov-Gerasimenko, over one hundred meter-sized bright spots have been identified in

The Chemical Composition of Comets—Emerging Taxonomies and Natal Heritage

Cometary nuclei contain the least modified material from the formative epoch of our planetary system, and their compositions reflect a range of processes experienced by material prior to its

Two independent and primitive envelopes of the bilobate nucleus of comet 67P

The notable structural similarities between the two lobes of comet 67P/Churyumov–Gerasimenko indicate that the early-forming cometesimals experienced similar primordial stratified accretion, even though they formed independently.

On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko

Images from the OSIRIS scientific imaging system onboard Rosetta show that the nucleus of 67P/Churyumov-Gerasimenko consists of two lobes connected by a short neck, which raises the question of whether the two Lobes represent a contact binary formed 4.5 billion years ago, or a single body where a gap has evolved via mass loss.