Highly anticipated new images of the interstellar comet 3I/ATLAS as it made its nearest pass to the planet Mars last week have been released by the European Space Agency (ESA), showcasing both the opportunities—and the challenges—that viewing the unusual object presents.
The new images, obtained by the ESA’s ExoMars Trace Gas Orbiter, reveal a view of the alien comet similar to those obtained in July by NASA’s Hubble Space Telescope, although at much closer range.
Additional data may have also been obtained by ESA spacecraft as 3I/ATLAS passed Mars, although the agency said it presently remains unclear whether the ExoMars or its sister spacecraft, the Mars Express orbiter, may have collected spectrographic information that could enable chemical analysis.
Initially discovered in early July, 3I/ATLAS has captured the fascination of the astronomical community due to its unusual characteristics, which include its size, speed, and a range of behaviors that are not consistent with comets native to our solar system.
During the interstellar comet’s recent flyby past Mars, the ESA trained the cameras aboard its ExoMars and Mars Express orbiter toward the object, although the shorter exposure times of the latter spacecraft prevented it from being able to obtain any imagery of the object.
Fortunately, ExoMars is equipped with the Colour and Stereo Surface Imaging System (CaSSIS) camera, which has a resolution of 11.36 micro-radians (≈2.34 arcseconds) per pixel, translating to 340 km per pixel at 30 million km distance.
Hellbound and Down 