Early on 8 April 2024, a citizen scientist found a comet in images from the ESA/NASA Solar and Heliospheric Observatory (SOHO). It follows the recent discovery of SOHO’s 5000th comet. But this one – named Comet SOHO-5008 – was special for a different reason.

Karl Battams (US Naval Research Lab), manager of the SOHO Sungrazer Project, predicted that comet SOHO-5008 would be visible during the total solar eclipse, which was due to plunge parts of the United States and Mexico into darkness later that very same day.

Petr Horálek, from the Institute of Physics in Opava (Czechia), was in Mexico for the eclipse. The clouds cleared and Petr could take this beautiful shot of the Sun’s awe-inspiring corona. To the lower left of the Sun, Comet SOHO-5008 is revealed.

Soon after Petr captured the comet on camera, it met its demise, coming so close to the Sun that it disintegrated.

Observations of these ‘sungrazing’ comets from the ground are extremely rare, and this sighting was only possible thanks to the total solar eclipse.

The image is a composite of 100 frames, with the wide corona imaged at a focal length of 200 mm (exposure time from 1/4000 to 2 seconds) and the inner corona imaged at a focal length of 1100 mm (exposure time from 1/500 to 4 seconds).

SOHO’s prowess as a comet-hunter was unplanned, but turned out to be an unexpected success. With its clear view of the Sun’s surroundings, SOHO can easily spot sungrazing comets. This has made it the most prolific discoverer of comets in astronomical history.

Click here to see the image without the inset.

SOHO is a cooperative effort between ESA and NASA. Mission control is based at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. SOHO’s Large Angle and Spectrometric Coronagraph Experiment (LASCO), the instrument that provides most of the comet imagery, was built by an international consortium, led by the US Naval Research Lab.