Eyes on the sky, people: Comet C/2023 A3 (Tsuchinshan–ATLAS) has a good chance of getting bright enough to be visible to the naked eye in the coming months. It is currently visible only to telescopes, but it is still quite a distance away from the Sun. It has time to get brighter, and could even get as bright as Venus, the brightest planet in the night sky, come October.
Its closest passage from the Sun will take place on September 27 and it will be 58.6 million kilometers (36.4 million miles) from our star. That’s a similar distance to Mercury. Then a few weeks after that on October 12, the comet will perform its closest pass to Earth, roughly 70.6 million kilometers (43.9 million miles) away.
Maximum magnitude might happen around that time. Some estimates suggest it will be brighter than all but four stars in the sky. An even more optimistic curve pushes it as brighter than Jupiter, and bit less bright than Venus. That would be an extremely bright comet – and it would be visible at sunset, making it a very convenient spectacle if it starts shining as bright as hoped.
The comet was discovered over 15 months ago independently by two observatories. First, by the Zijinshan Astronomical Observatory (Purple Mountain Observatory), but it was very faint and it was lost in follow-up observations. It was then found again by the Asteroid Terrestrial-impact Last Alert System (ATLAS) South Africa. Following the discovery, it was found in older observations from December 2022.
Dr. Sarah Adams is a scientist and science communicator who makes complex topics accessible to all. Her articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
