Catching a comet
Special Issue | 23 January 2015
Science's special section contains the first published scientific results from Rosetta at comet 67P.
Read the full introduction
Image portrays the Earth, the Moon and Comet 67P/Churyumov-Gerasimenko showing how they would appear in the same light conditions,
taking in account their relative albedos, the percentage of light reflected by the body. The Earth reflects 31% of the light,
the Moon 12% and Comet 67P about 6%. The images are not to scale physically.
Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA & Gordan Ugarkovich (Earth); Robert Vanderbei,
Princeton Univ (Moon); ESA/Rosetta/NAVCAM (67P/C-G)
A comet with an unusual shape has an array of surface features and high porosity, with early outgassing between its two lobes.
Images with better than 1-meter-per-pixel resolution shows a comet’s morphology with evidence for complex active processes.
Observations of the dust outflow show bound and unbound grains and imply a comparatively high dust-to-gas ratio of 4.
Diversity of features points to a more complicated cometary birth.
Highlights from previous news coverage:
In situ mass spectrometry reveals a deuterium-to-hydrogen ratio three times that of Earth, which is suggestive of diverse
origins for comets in this class.
The reflectance behavior of an illuminated comet is consistent with the presence of nonvolatile organics and sparse water
Mass spectrometry performed in situ shows a highly heterogeneous coma with large diurnal and possibly seasonal variations.
The interaction of the solar wind and a comet atmosphere is characterized through detection of the energetic ion environment.
Measurements at a comet yield water production rates and an assessment of low thermal inertia.
ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
2014 Breakthrough of the Year: Landing on a comet