Read on Twitter
Thread: (1) This is interesting... did the Mars Express orbiter happen to photograph another (old) orbiter still circling Mars? This is a Mars Express seminar from August 21, 2020, with Prof. Ralf Jaumann, a professor at the Free University of Berlin and principal investigator...
(2) ...of the High Resolution Stereo Camera (HRSC) on Mars Express. I included a screenshot below of the object seen. Some debate on Twitter about whether it is an imaging artifact, although Jaumann doesn& #39;t think so and says it was about 20 km from Mars Express...
(3) ...There are several defunct spacecraft still orbiting Mars, but this would be unusually close. 
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🤔" title="Denkendes Gesicht" aria-label="Emoji: Denkendes Gesicht">
https://www.issibern.ch/index.php/2020/08/20/mars-express
Original">https://www.issibern.ch/index.php... images are here, archived in 2018 but taken in 2017:
https://pds-geosciences.wustl.edu/mex/mex-m-hrsc-3-rdr-v3/mexhrs_1001/data/g472/">https://pds-geosciences.wustl.edu/mex/mex-m...
https://www.issibern.ch/index.php/2020/08/20/mars-express
Original">https://www.issibern.ch/index.php... images are here, archived in 2018 but taken in 2017:
https://pds-geosciences.wustl.edu/mex/mex-m-hrsc-3-rdr-v3/mexhrs_1001/data/g472/">https://pds-geosciences.wustl.edu/mex/mex-m...
https://www.issibern.ch/index.php... images are here, archived in 2018 but taken in 2017: https://pds-geosciences.wustl.edu/mex/mex-m..." title="(3) ...There are several defunct spacecraft still orbiting Mars, but this would be unusually close. https://abs.twimg.com/emoji/v2/... draggable="false" alt="🤔" title="Denkendes Gesicht" aria-label="Emoji: Denkendes Gesicht"> https://www.issibern.ch/index.php... images are here, archived in 2018 but taken in 2017: https://pds-geosciences.wustl.edu/mex/mex-m..." class="img-responsive" style="max-width:100%;"/>
