Unique moment: "Comet of the century" is on its way and will be visible from Earth later this year

Comet discovered in 2023 has been nicknamed the “comet of the century” and will be visible later this year when it passes close to Earth.

This year we will be able to observe a comet that only appears once a century and we will have a privileged location.
This year we will be able to observe a comet that only appears once a century and we will have a privileged location.

One of the most anticipated astronomical events for all skywatchers is the passing of a comet. This is because when a comet passes close to Earth, it is possible to observe a tail that extends for kilometres. Because of this, photographs and observations of comets produce unique images that attract the attention of many people.

The best-known comet is the so-called Halley's Comet, which passes close to Earth every 75 years. It last passed between 1985 and 1986, but because of the position of the Earth in relation to it, it ended up being an apparition that was not very visible. Despite this, several comets pass close to Earth every year and it is possible to observe them in different regions of the globe.

The "Comet of the Century" will be visible mainly in the Southern Hemisphere in late September and will increase in brightness as it moves across the sky. It will make its closest approach around the weekend of 11 October.

One that is being talked about is the comet C/2023 A3 (Tsuchinshan–ATLAS) which was discovered in January 2023. It is expected to pass close to Earth between September and October of this year when it will be possible to observe it with the naked eye. The nickname that the comet received is due to the fact that it only passes by every 80 years, so it is possible to see it practically once a century.

Comets

Comets are astronomical objects that attract attention every time they pass near Earth. These bodies are composed of ice and rock, so as they approach the Sun, some components sublimate, creating one or two tails. These tails are ionised gas that ends up being pushed by solar winds or by solar radiation itself.

Comets have their origins associated with the most extreme regions of the Solar System, such as the Kuiper Belt and the Oort Cloud.

Comets generally have very elliptical trajectories around the Sun, unlike planets, which have a much lower eccentricity. This is unlike the orbits of planets, which are very close to a circle. Because they originate at the edge of the Solar System, comets are a source of study to understand how the planets furthest from the Sun were formed.

Oort Cloud

One of the regions assumed to be the point of origin of comets is the so-called Oort Cloud. This region is located about 1 light-year away from the Sun, is one of the last structures in the Solar System and is the boundary with interstellar space. The Oort Cloud would be composed of rocks that would be frozen due to the lack of a heat source.

The Oort Cloud is the last structure in the Solar System and is located at the boundary with the interstellar medium. Credit: StarWalk
The Oort Cloud is the last structure in the Solar System and is located at the boundary with the interstellar medium. Credit: StarWalk

It emerged as an explanation for the origin and trajectory of comets with high eccentricity. The idea is that due to the interaction of the Solar System with nearby stars, the frozen rocks would suffer gravitational disturbances. With these gravitational disturbances, the rocks could be thrown towards the interior of the Solar System giving rise to the objects we know as comets.

Comet of the century

In January 2023, astronomers at the Purple Mountain Observatory recorded images of the comet, but it was not until astronomers at the Sutherland Observatory observed it in February of the same year that the object attracted attention. After these observations, the comet began to be closely monitored by observatories and telescopes around the world. These observations showed that there is a strong emission of cyanide.

Century Comet was observed by different observatories around the world as it approaches the earth. Credit: Gianluca Masi
Century Comet was observed by different observatories around the world as it approaches the earth. Credit: Gianluca Masi

During this year, more records of the comet that was named the comet of the century were made. In July, a tail could already be seen in photos of the approaching comet. The nickname “comet of the century” is due to the fact that it has a period of 80 years, indicating that it can be observed practically once a century in a similar way to Halley's comet.

Observation

Many astronomers and enthusiasts are excited about the approach of the comet of the century, which will become increasingly visible in the coming months. It will be visible mainly in the Southern Hemisphere at the end of September and will increase in brightness as it moves across the sky. It will come closest around the weekend of October 11th. Because of its brightness, it will be visible to the naked eye and no special equipment will be needed to observe it.

Now the important thing is to hope that the weather conditions allow observation during the week of October and that the sky will be clear to record the unique moment of the comet of the century.