Search Publications
Macro and micro structures of pebble-made cometary nuclei reconciled by seasonal evolution
Longobardo, Andrea; Mottola, Stefano; Kappel, David +17 more
Comets evolve due to sublimation of ices embedded inside porous dust, triggering dust emission (that is, erosion) followed by mass loss, mass redistribution and surface modifications. Surface changes were revealed by the Deep Impact and Stardust NExT missions for comet 9P/Tempel 1 (ref. 1), and a full inventory of the processes modifyin…
Dual storage and release of molecular oxygen in comet 67P/Churyumov-Gerasimenko
Mousis, Olivier; Trattner, Karlheinz J.; Lunine, Jonathan I. +7 more
One of the biggest surprises of the Rosetta mission was the detection of O2 in the coma of 67P/Churyumov-Gerasimenko in remarkably high abundances. The measured levels of O2 in the coma are generally assumed to reflect the overall abundance and chemical origin of cometary O2 in the nucleus. Along with its strong as…
A non-energetic mechanism for glycine formation in the interstellar medium
van Dishoeck, E. F.; Kofman, V.; Ioppolo, S. +8 more
The detection of the amino acid glycine and its amine precursor methylamine on the comet 67P/Churyumov-Gerasimenko by the Rosetta mission provides strong evidence for a cosmic origin of amino acids on Earth. How and when such molecules form along the process of star formation remains debated. Here we report the laboratory detection of glycine form…
Evidence of ammonium salts in comet 67P as explanation for the nitrogen depletion in cometary comae
De Keyser, Johan; Gombosi, Tamas I.; Berthelier, Jean-Jacques +14 more
Cometary comae are generally depleted in nitrogen. The main carriers for volatile nitrogen in comets are NH3 and HCN. It is known that ammonia readily combines with many acids, such as HCN, HNCO and HCOOH, encountered in the interstellar medium as well as in cometary ice to form ammonium salts (NH4+X-) a…
Infrared detection of aliphatic organics on a cometary nucleus
Bellucci, G.; Carlson, R. W.; Fornasier, S. +28 more
The European Space Agency's Rosetta mission1 has acquired unprecedented measurements of the surface of the nucleus of comet 67P/Churyumov-Gerasimenko (hereafter, 67P), the composition of which, as determined by in situ and remote-sensing instruments, including the VIRTIS instrument2, seems to be an assemblage of ices, mineral…
Far-ultraviolet aurora identified at comet 67P/Churyumov-Gerasimenko
Altwegg, K.; Feldman, P. D.; Carr, C. +14 more
Having a nucleus darker than charcoal, comets are usually detected from Earth through the emissions from their coma. The coma is an envelope of gas that forms through the sublimation of ices from the nucleus as the comet gets closer to the Sun. In the far-ultraviolet portion of the spectrum, observations of comae have revealed the presence of atom…
The changing temperature of the nucleus of comet 67P induced by morphological and seasonal effects
Bellucci, G.; Kührt, E.; Mottola, S. +31 more
Knowledge of the surface temperature distribution on a comet's nucleus and its temporal evolution at different timescales is key to constraining its thermophysical properties and understanding the physical processes that take place at and below the surface. Here we report on time-resolved maps of comet 67P/Churyumov-Gerasimenko retrieved on the ba…
Catastrophic disruptions as the origin of bilobate comets
Richardson, Derek C.; Jutzi, Martin; Michel, Patrick +3 more
Several comets observed at close range have bilobate shapes1, including comet 67P/Churyumov-Gerasimenko (67P/C-G), which was imaged by the European Space Agency's Rosetta mission2,3. Bilobate comets are thought to be primordial because they are rich in supervolatiles (for example, N2 and CO) and have a low bulk den…
Coma morphology of comet 67P controlled by insolation over irregular nucleus
Jorda, L.; Lamy, P. L.; Lara, L. M. +42 more
While the structural complexity of cometary comae is already recognizable from telescopic observations1, the innermost region, within a few radii of the nucleus, was not resolved until spacecraft exploration became a reality2,3. The dust coma displays jet-like features of enhanced brightness superposed on a diffuse background…
The pristine interior of comet 67P revealed by the combined Aswan outburst and cliff collapse
Jorda, L.; Lara, L. M.; Bertaux, J. -L. +61 more
Outbursts occur commonly on comets1 with different frequencies and scales2,3. Despite multiple observations suggesting various triggering processes4,5, the driving mechanism of such outbursts is still poorly understood. Landslides have been invoked6 to explain some outbursts on comet 103P/Hartley 2, alth…