Meet the heart of Comet 67P/Churyumov-Gerasimenko!

Our new images from the camera system OSIRIS on ESA’s spacecraft Rosetta shows that Comet 67P/Churyumov-Gerasimenko has a spectacularly shaped nucleus! The nucleus consists of two large pieces with different shape, connected at a small contact surface.


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A sequence of 36 processed images of Comet 67P/Churyumov-Gerasimenko taken 20 minutes apart on July 14, 2014, from a distance of about 12,000 kilometers. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA


 

One should not look too closely for details in a movie like this. The reasons is clear once we look at one of the original images below. The camera has a limited resolution and the original image consists of a number of squares, or “pixels”, that each have recorded a certain light intensity. We do not know how the nucleus looks like within each pixel – but we can guess!


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An original picture from OSIRIS before image processing. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA


 

During so-called image processing, mathematical algorithms are used in an attempt to re-create how an object really looks like, before it got smeared out by the pixels. Such algorithms are good at re-creating lost information, but they are not perfect. Real surface structures may have been lost completely, while false features that do not exist in reality may have been added.


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A processed image from OSIRIS. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA


 

The only way to find out how the comet surface really looks like is to get closer – and in a short while Rosetta will be much closer to the comet!


The scientific imaging system OSIRIS was built by a consortium led by the Max Planck Institute for Solar System Research (Germany) in collaboration with CISAS, University of Padova (Italy), the Laboratoire d’Astrophysique de Marseille (France), the Instituto de Astrofísica de Andalucia, CSIC (Spain), the Scientific Support Office of the European Space Agency (The Netherlands), the Instituto Nacional de Técnica Aeroespacial (Spain), the Universidad Politéchnica de Madrid (Spain), the Department of Physics and Astronomy of Uppsala University (Sweden), and the Institute of Computer and Network Engineering of the TU Braunschweig (Germany). OSIRIS was financially supported by the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), and Sweden (SNSB) and the ESA Technical Directorate.

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OSIRIS: First glimpse of the comet nucleus!

Up to just a few days ago, the target of ESA’s Rosetta mission, Comet 67P/Churyumov-Gerasimenko, was just a dot in the sky, barely distinguishing itself from the stars by displaying a small temporary dust coma. But now Rosetta is getting so close to the comet, 40 000 kilometers – about a tenth of the distance between Earth and the Moon – that the OSIRIS camera starts to resolve the nucleus. The comet nucleus is still just a couple of camera pixels across, but as seen in the movie below, there is a hint of nucleus irregularity. The nucleus size and shape changes slightly, while it is rotating with its 12.4 hour period. From now on, the comet nucleus will just grow in size until it fills the entire field of view of the Narrow Angle Camera (NAC) in mid August. Stay tuned for more cool pictures from OSIRIS!


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First resolved images of comet 67P/Churyumov-Gerasimenko show the nucleus rotating with a rotation period of 12.4 hours. This set of 36 images was obtained by OSIRIS’ narrow angle camera (NAC) on June 27th and June 28th and covers one such period. © ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA


The scientific imaging system OSIRIS was built by a consortium led by the Max Planck Institute for Solar System Research (Germany) in collaboration with CISAS, University of Padova (Italy), the Laboratoire d’Astrophysique de Marseille (France), the Instituto de Astrofísica de Andalucia, CSIC (Spain), the Scientific Support Office of the European Space Agency (The Netherlands), the Instituto Nacional de Técnica Aeroespacial (Spain), the Universidad Politéchnica de Madrid (Spain), the Department of Physics and Astronomy of Uppsala University (Sweden), and the Institute of Computer and Network Engineering of the TU Braunschweig (Germany). OSIRIS was financially supported by the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), and Sweden (SNSB) and the ESA Technical Directorate.