The spacecraft designed for solar observation, the Solar and Heliospheric Observatory (SOHO), which collects data on the activity of our star, was monitoring a solar flare when a bright object unexpectedly appeared in the frame. It turned out to be the comet C/2023 A3 (Zizjingshan - ATLAS).
The "head," or coma, of C/2023 A3 extends approximately 209,000 kilometers, while its tail measures about 29 million kilometers in length. As a result, the comet has been in the view of SOHO for several days.
C/2023 A3 will make its closest approach to our planet on October 12, 2024: the distance will be about 0.47 astronomical units, or roughly 70.6 million kilometers. The comet will be bright enough for people on Earth to observe it with the naked eye.