The comet of the century is arriving: here’s how to see it

It was discovered last year by two telescopes. From these it took its name comet of the century and from the year it was sighted: its name C/2023 A3 Tsuchinshan-Atlas. These days it approaches Earth and has its peak brightness for October 9 and the following days. It may be brighter than many stars and the planet Venus.

The ancients

The ancients certainly did not call this phenomenon with English terms, but there is no doubt that comets exerted great fascination on them given that they made extraordinary and often unexpected appearances. Explain the **Virtual Telescope Project **that ancient chronicles report “sinister omens associated with this or that bright star with a tail”. The comet of the Nativity is just one of the possible examples.

The most recent precedents

In the summer of 2020, comet C/2020 F3 Neowise was visible to the naked eye even from cities. The passage of comet Hale-Bopp occurred in 1997. In 2009, the large comet C/2006 P1 McNaught could be seen in the southern sky.

C/2023 A3 Tsuchinshan-Atlas

The first observations made known date back to February 22, 2023 and were carried out with a telescope installed in South Africa, part of the ATLAS (Asteroid Terrestrial-impact Last Alert System) project. The Minor Planet Center later linked this new star to previously reported observations from the Purple Mountain Observatory, China, on January 9. Upon the official announcement of its discovery, the comet took the name C/2023 A3 Tsuchinshan-ATLAS with Tsuchinshan being a transliteration of the Mandarin name of the Chinese observatory.

From the beginning, explains the Virtual Telescope website, it was noted that the comet could have become interesting shortly after its passage to perihelion, i.e. the minimum distance from the Sun, it will reach approximately 60 million km on September 27, 2024.

Gianluca Masi, astrophysicist responsible for the Virtual Telescope Project, explained that the position of the comet, which is almost in alignment with the Earth and the Sun, could be particularly bright thanks to the exploitation of the forward scattering effect, for which the dust comets reflect sunlight directly towards Earth, our observation point.

The dust present in the comet preferably rejects sunlight forwards, therefore if a comet passes between us and the Sun its brightness can be increased tens, hundreds or thousands of times.

When, how and where to see it

The peak brightness due to forward scattering is expected on October 9thwhen the comet will be prospectively very close to the Sun. Only in the following days will its visibility from Earth gradually improve, but the brightness will decrease rapidly. The comet will be low on the horizon just after sunset.

On October 12, C/2023 A3 will be at its closest distance from Earthequal to approximately 71 million km. From then on, day after day, the comet will gradually be better placed in the sky, albeit less and less favored by the increase in splendor due to scattering. Around October 15th it should be possible to get the best view of the comet’s brightness and its position in the sky. Only from October 17th will the interference of the Moon’s light be felt.

It is advisable to choose a site as free as possible from light pollution and which offers the western horizon free from major obstacles. Observation can be conducted with the naked eye, preferably with binoculars.