How to see the 'Comet of the Century' from so close to Earth

Its technical name – C/2023 A3 Tsuchinshan-ATLAS – is too long, but the nickname given by scientists describes it for what it is: “The Comet of the Century”.

The comet's passage is considered by the scientific community to be one of the biggest astronomical events of 2024.

This luminous cosmic object will enter its best viewing phase in the sky this Saturday (12/10). And if someone makes a mistake, they have to wait another 80,000 years for that chance.

The comet was identified last year by the Tsuchinshan-ATLAS Observatory in China, which explains the technical name. It passed closest to the Sun in late September.

“Scientists hypothesized that it would disintegrate during this passage [pelo Sol]Its volatile, icy composition could not withstand the intense heat of our parent star, but it survived more or less intact,” explained astronomer Bill Cook via a NASA bulletin.

Now it will pass very close to Earth, at a distance of about 70 million kilometers, and will be visible from October 12.

“Bright comets are very rare,” Robert Massey, deputy director of the Royal Astronomical Society of Great Britain, explains to the BBC.

“So, if you get a chance to see one, go for it, even if you have to use binoculars to see the tail and its features. “They are absolutely beautiful.”

Comets are small celestial bodies orbiting the Sun, composed mainly of ice, dust, and rocky material. As a comet approaches the Sun, the heat evaporates the ice, forming a tail. They travel on a large orbit, which means they can be thousands of years away from the inner part of the solar system.

Where and how to see the 'comet of the century'?

From late September onwards, this comet's progress is observed from the Southern Hemisphere, close to the horizon, so only wide viewing locations with a good view of the horizon are ideal.

However, beginning in the middle of this month, the comet will be visible in the Northern Hemisphere, slightly higher in the sky, during dusk or evening, according to NASA. According to NASA, it is much less noticeable during the day.

Cook recommends choosing a dark spot to watch after dark. Looking southwest, about 10 degrees above the horizon, Tsuchinshan-ATLAS is visible between the constellations Scorpius and Sagittarius.

In the second half of the month, the comet will move across the sky, one of the brightest in the night sky, the star Arcturus and the planet Venus. There are cell phone applications that allow you to view the position of these constellations, stars and planets.

As with other similar cases, it is preferable to observe in a place free of light pollution. Pages like the Light Pollution Map allow you to find out where urban centers are most likely to have light-free skies.

Under ideal conditions, it can be seen with the naked eye. But it is better to have binoculars or a simple telescope.

Tsuchinshan-ATLAS will only be visible from Earth in late October, as it disappears the following month and will not approach the Solar System again for 80,000 years.

'Comet of the Century'

Bright comets visible from Earth are actually few and far between, which is why Tsuchinshan-ATLAS is called the “Comet of the Century”.

Unlike asteroids, which are composed exclusively of rocks, comets are composed of ice, rock, and gas.

As they approach the Sun, the heat turns the ice into gases and releases dust particles trapped in the ice, causing the famous “tail”.

After its location in January 2023, it was speculated to be one of the brightest comets in recent years. Expectations are diminishing, but it still feels good.

Some photographers have captured stunning images of its glow with long exposure techniques.

According to NASA, only nine comets in the past 300 years have been bright enough to be seen during the day, the most recent being West in 1976 and Hale-Pop in 1997.

“The brightness of comets is measured using the same scale we use for stars, which has been in use since it was devised by the ancient scholar Hipparchus in 150 BC and perfected by the astronomer Ptolemy,” explains NASA.

On this logarithmic scale, the lower your registration, the clearer the object will be with binoculars or the naked eye.

The brightness of Tsuchinshan-ATLAS is rated between 2 and 4. “By comparison, Sirius, the brightest star visible in the night sky, has a magnitude of -1.46. At its brightest, Venus' solar magnitude is -4. The International Space Station sometimes reaches a relative brightness of -6.

Massey says we should be wary of something in the future that can seduce us with its beauty. “Is this the brightest comet in the last 100 years? I doubt it.”

Comet Neowis, impressed during the 2020 pandemic, had a brightness that could not be surpassed this month.

However, this is no reason to miss the opportunity: “Comets are unpredictable, but we never know when the next one will appear, so don't miss this opportunity.”