Data from a solar observing satellite has found something it wasn’t designed to do for the 5,000th time, a comet.

The Solar and Heliospheric Observatory (SOHO) spacecraft, launched in December 1995, has been studying the sun and the solar wind since that time. It also collects data about coronal mass ejections that can damage electric grids and create vibrant auroras that extend beyond the polar region.

One of SOHO’s instruments uses an artificial disk to block out the sun’s light, so that the corona and the sun’s outer atmosphere is viewable.

This set-up has also produced a treasure trove of other data unrelated to the Sun. In the 28 years of operation, researchers, including citizen scientists, scouring these images have found 5,000 comets orbiting the sun.

The astronomy doctoral candidate that found the milestone comet has been looking for comets in the SOHO data since he was 13 and has found 200 on his own. The program has been so successful that NASA had to create a new reporting system to catalogue comet findings.

These comets wouldn’t likely have been detected otherwise since they only begin to glow when they pass near the sun. These newly discovered comets have offered new insight into the sun’s atmosphere and how comets orbit the Sun.

The SOHO mission was only designed to last two years, but the spacecraft mission has been extended to 2025, a full 30-years after launch. Who knows how many more comets there are to be found.