COMET. Visible to the naked eye, comet C/2023 P1 Nishimura is gradually gaining in luminosity. When and how to observe it? Our recommendations so you don’t miss a thing!

[Updated September 11, 2023 4:23 PM] Discovered on August 11 by a Japanese amateur astronomer, Comet C/2023 P1, also known as Comet Nishimura after its discoverer, has approached our planet. On Wednesday, September 13, it should be 128 million kilometers from Earth before passing close to the Sun, a perilous stage of its journey, which it may not resist.

Before getting closer to the Sun, the comet is visible in the sky and offers us a beautiful show. When can it be observed with the naked eye? How to find it in the sky? We tell you everything about the passage of this small body of ice and dust from the depths of the solar system.

Comet C/2023P1 was discovered by a Japanese amateur astronomer named Hideo Nishimura on August 11. It was then evolving in an area located very close to the Sun which it should gradually approach. It will pass closest to the latter on September 18 at only 33 million kilometers.

According to the specialist site Star Walk, it is possible that this comet is periodic and passes close to Earth approximately every 300 years. This means that it may have already been seen by some of our ancestors in the 18th or even the 15th century…

Comet Nishimura will pass through different constellations during its journey. So, you will find it in the constellation Leo between September 7th and 15th. From this date, the comet will be difficult to see in the light of dawn, but if its brightness allows it, it will be visible in the constellation of Virgo.

There are tools that will make it easier for you to locate the comet in the sky. This is the case of the Star Walk 2 applications (available on Google Play and App Store) and Sky Tonight (available on Google Play and App Store).

To have a chance of seeing comet Nishimura, you have to be early since it appears around 5:30 a.m. in the constellation Cancer. The more the days progress, the later its passage above the horizon. It then blends in with the lights of dawn and its observation becomes more and more delicate. Until September 13, we can hope to be able to admire it despite the sunrise.

Comet Nishimura has been visible to the naked eye since September 7, 2023. Its magnitude, or brightness, is 4.3, meaning it is bright enough to be visible without tools.

You can also photograph a comet when it is visible to the naked eye with a simple camera with manual settings. You will use a wide angle lens using fairly long exposures like 20 seconds and ISO 1600 (minimum 800). Be careful, if light pollution is significant, you should lower the ISO. Think about composition, placing the comet on top of a building or tree, or between two mountains. If you don’t have a tripod, use a self-timer to prevent the photo from being blurry when taken.

Also in 2023, comet 103P Hartley could also “graze” Earth on October 13, 2023.

A comet is a celestial body made up of frozen gases, rocks and dust that originated from the formation of the solar system. These are real cosmic snowballs. So when this type of object passes close to the Sun, the latter heats the comet and melts the material. The comet then begins spewing dust and gas in a gigantic glowing form, much larger than most planets. The size of a comet can vary from a few kilometers to tens of kilometers wide, when it orbits closest to the Sun. When its substances flow out, they form a spectacular cloud of gas and dust that trails behind it for millions of kilometers and that is when it can be seen from Earth with the naked eye .

Two tails form behind the comet. The first is made up of dust and is directly linked to the movement of the object. It is the most spectacular because it can measure several million kilometres. The second is made up of gas and is called the ionized tail.

Comets are formed from materials left over from the formation of the solar system. These objects are therefore witnesses to the formation of the solar system. “This material has not evolved, it has been preserved intact, as if it had been placed in the freezer, and it is therefore the witness of these first moments.” said astrophysicist Françis Rocart, head of the Rosetta program in an article in Le Monde in 2014.

The nucleus of a comet is composed of frozen gases in the form of ice, rocks and rock dust. Studies of Comet Tchouri indicate that it is also covered in carbon and have also spotted many organic molecules that have never before been identified anywhere other than Earth. Thus, it could be that the elements which allowed the appearance of life on our planet came from space and were brought by an intensive bombardment 4 billion years ago. To find out more, we would have to study the composition of many other comets…