In the early months of 2023, astronomers and stargazers alike were blessed with a rare celestial object that raced through the skies of the Northern Hemisphere – the sight of the “Green Comet”, also known as C/2022 E3 (ZTF). Although news media created large anticipation for the comet – often using pictures of the bright Comet NEOWISE -, which C/2022 E3 (ZTF) unfortunately did not live up to. At most, it was visible in dark skies as a fuzzy clump of green, and detectable in city skies through astrophotography setups.
However, 2024’s story may be different.
C/2023 A3 (Tsuchinshan-ATLAS) is an icy body of rocks, ice, and dust that originates from the Oort Cloud – the outermost edges of our Solar System, past Pluto and the Kuiper Belt. It was first discovered by the Zwicky Transient Facility (ZTF) – yes, this is the same facility that discovered C/2022 E3 (ZTF)! – on the 22nd of December in 2022, but was confirmed by South Africa’s ATLAS telescopes on the 22nd of February, 2023. Currently, the comet is approaching the inner solar system at speeds of 15.7km/sec, and is currently just above 7 astronomical units (AU) away from the Sun.
Astronomers estimate that C/2022 A3 will make its perihelion on September 28th, 2024. It will fly by the sun, displaying an ion tail and dust tail as the comet body begins to melt due to UV radiation. After swinging by the Sun, the comet is predicted to make its closest approach on October 13th of the same year. When the comet does make the approach into the inner solar system, astronomers predict that it may reach magnitudes of -5 – similar to the magnitude of Venus, which is the brightest planet visible in our night sky.
Of course, this early on, it is impossible to tell if C/2022 A3 will live up to its predicted expectations. Currently, astronomers have no way of telling the general composition of the comet until it gets closer to the inner solar system. Comets are unpredictable both in their brightness and size, and their tails may change in magnitude and shape every hour as they get closer to our star. However, if the comet does exceed our expectations, it will be a spectacular sight in the night sky and will be an event worth looking out for.
Image from https://en.wikipedia.org/wiki/C/2023_A3_(Tsuchinshan%E2%80%93ATLAS)