The European Space Agency (ESA) on Tuesday published a set of images sent down by the Rosetta satellite on Comet 67/Churyumov–Gerasimenko, revealing a shadow of its own selfie taken with its own OSIRIS camera system.
According to scientists, this is the first ever selfie taken by the Rosetta using its own camera technology on the face of a comet – and it shows a picture taken on a very fast-moving celestial object.
ESA revealed that the Rosetta’s OSIRIS scientific imaging camera was equipped with a 700 mm narrow-angle lens, and a 140mm wide-angle lens, and a 2048×2048 pixel CCD chip.
And technically speaking, the captured image is not actually a selfie per se, but an image detailing the Rosetta’s shadow cast on the Comet 67P during its flyby last month.
ESA explained that the photos were shot when Rosetta was about 6 kilometers away from the surface of the comet; and in spite of the escape velocity speed of 3 feet per second recorded by the comet, the OSIRIS was still able to capture the photo with just 11 cm-per-pixel resolution.
ESA offered an explanation that the shadow image shot by the Rosetta on Comet 67/P was wide, rectangular, and sort of fuzzy because the position of the sun when the image was taken added the effects.
“The Sun appeared as a disc about 0.2 degrees across (about 2.3 times smaller than on Earth), resulting in a fuzzy “penumbra” around the spacecraft’s shadow on the surface,” ESA said in a statement.
This means that the distance of the Rosetta from the comet aided the penumbra effect that added about 20 meters to the Rosetta’s real dimensions.
It is expected that Comet 67P will reach perihelion or its closest flyby from the Sun on August 13 of the date on Earth.