                        Astronomy Picture of the Day

    Discover the cosmos! Each day a different image or photograph of our
      fascinating universe is featured, along with a brief explanation
                    written by a professional astronomer.

                              2023 November 26
    A dark and jagged hill is shown strewn with rocks. On the slope is a
    white foggy area that appears to emanate from a non-descript place on
         the rock face. Please see the explanation for more detailed
                                information.

                  A Dust Jet from the Surface of Comet 67P
                  Image Credit: ESA, Rosetta, MPS, OSIRIS;
                      UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

   Explanation: Where do comet tails come from? There are no obvious
   places on the nuclei of comets from which the jets that create comet
   tails emanate. In 2016, though, ESA's Rosetta spacecraft not only
   imaged a jet emerging from Comet 67P/Churyumov-Gerasimenko, but flew
   right through it. Featured is a telling picture showing a bright plume
   emerging from a small circular dip bounded on one side by a 10-meter
   high wall. Analyses of Rosetta data show that the jet was composed of
   both dust and water-ice. The rugged but otherwise unremarkable terrain
   indicates that something likely happened far under the porous surface
   to create the plume. This image was taken about two months before
   Rosetta's mission ended with a controlled impact onto Comet 67P's
   surface.

                        Tomorrow's picture: eagle ray
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
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                             & Michigan Tech. U.

