On September 28, NASA astronauts captured stunning images of a comet from the International Space Station. This month, stargazers have an extraordinary opportunity to witness Comet C/2023 A3 (Zijinshan-Atlas) making its appearance in the northern hemisphere’s night sky. The comet will be visible shortly after sunset in the western sky, offering a rare celestial spectacle that can be observed with the naked eye. With an orbital period of over 10,000 years, this will be a once-in-a-lifetime event, as it won’t be seen again for millennia. Astronomy enthusiasts in the San Francisco Bay Area are gearing up to make the most of this remarkable observation opportunity.
According to NASA, Comet C/2023 A3 was discovered in 2023 through a collaboration between China’s Nanjing Zijinshan Observatory and the ATLAS asteroid observation system. This ancient and mysterious comet is believed to originate from the distant Oort Cloud, a vast region surrounding our solar system filled with interstellar debris and celestial bodies. The Oort Cloud, which is incredibly far away, contains billions of icy objects, many of which, like this comet, have orbital periods that take thousands or even tens of thousands of years to approach Earth. This particular comet takes approximately 60,000 to 80,000 years to complete one orbit around the Sun, making it one of the most anticipated comets of 2024.
Starting on October 12, Comet C/2023 A3 has become an evening star shortly after sunset, located very low in the western sky near Virgo. Its brightness has reached negative magnitudes, making this the prime time for observation. Many amateur astronomers in the San Francisco Bay Area have already been able to spot it with the naked eye and even photograph it using just their smartphones.
From October 13 to 14, although the comet’s brightness began to decrease to between magnitude 0 and 1, observations became easier as it moved slightly farther from the Sun. On October 15, it will be in close proximity to the M5 globular cluster, presenting an excellent opportunity for photographers. Additionally, observers may notice a phenomenon called the anti-tail, a bright streak pointing toward the Sun, opposite the traditional tail of the comet.
Scientists have noted that the comet’s brightness will continue to diminish over time. Between October 20 and 31, its brightness is expected to drop from magnitude 4.5 to 7, at which point its tail will become noticeably longer. For enthusiasts hoping to catch sight of this celestial marvel, NASA recommends finding an open area away from city lights after sunset to increase the chances of observation. Binoculars or small telescopes are suggested for a better viewing experience. For those wishing to capture clearer images of the comet, using a camera with a long exposure setting will yield excellent results.
