Framed by the Milky Way and accompanied by meteors, in recent days, the most anticipated comet of the year—the Zijing Mountain-Atlas Comet—has captivated the public's attention. Astronomy experts have stated that after delivering nearly a month of spectacular performances, this "visitor from beyond" is now saying its "farewells" to Earth.
The Zijing Mountain-Atlas Comet (International designation C/2023 A3) was first observed on January 9, 2023, by the Near-Earth Object Telescope at the Zijing Mountain Observatory of the Chinese Academy of Sciences, marking it as the eighth comet discovered by the observatory.
Comets are small bodies within the solar system, primarily composed of ice, dust, and other materials. While comets are beautiful, they are not always easy to see. Most comets are relatively faint and typically require telescopes or other specialized equipment for observation and photography; truly visible comets are rarities.
Jiang Chenming, a co-initiator of the Astronomical League CSVA, explains that the Zijing Mountain-Atlas Comet originates from the distant Oort Cloud and is a typical near-parabolic comet. This is a long-period comet, with an orbital period extending over 60,000 years.
One of the defining characteristics of comets is their unpredictability; sometimes a comet that is expected to shine brightly may disintegrate during its approach to perihelion due to its loose structure, which finds it difficult to withstand intense solar heating and strong gravitational forces.
Fortunately, the Zijing Mountain-Atlas Comet has withstood such tests. On September 28 of this year, it successfully passed perihelion. For the Northern Hemisphere, this comet appeared in the low eastern sky during the mornings around the time of perihelion, and under conditions of high atmospheric transparency, its silhouette could be faintly observed with the naked eye.
On October 12, the Zijing Mountain-Atlas Comet passed its closest point to the Sun. For a period following this event, the comet would be visible shortly after sunset in the southwestern night sky. With this more convenient observation window, many astronomy enthusiasts have engaged in continuous tracking and photography of it. It is noteworthy that in the days following its closest approach, the comet is relatively easier to see with the naked eye.
"From the time around perihelion to just after the closest approach, the Zijing Mountain-Atlas Comet has become a stunning highlight in the sky, whether framed by famous landmarks or accompanying the Milky Way and meteors, bringing us immense joy," said Jiang Chenming.
Currently, the Zijing Mountain-Atlas Comet is moving away from Earth, and its brightness has decreased to magnitudes 4 to 5, indicating that its remarkable display is coming to an end.
Jiang Chenming has pointed out that as a long-period comet, we are unlikely to witness the Zijing Mountain-Atlas Comet again during our lifetimes. For those interested, it would be worthwhile to take a look through a telescope or other specialized gear. In the coming days, this comet will get increasingly closer to the Milky Way, ultimately "intersecting" with it, which will serve as the final "gift" this "visitor from beyond" leaves us.
