Comet NEOWISE (C/2020 F3) over the Badlands and Formations of Dinosaur Provincial Park, Alberta, … [+]
After months of waiting, a comet that could prove bright enough to be seen with the naked eye and even during the day from the northern hemisphere has arrived — and the first pictures are in.
“If it survives its close pass to the sun, becoming one of the brightest objects visible in the northern hemisphere – like Comet McNaught in 2007 – Comet A3 could prove to be one of the most significant celestial events of the year or even the decade ». said Franck Marchis, director of citizen science at the SETI Institute and co-founder of smart telescope maker Unistellarwhich has a learning page dedicated to the comet. “Observations will, theoretically, provide answers as to whether it will reach magnitude -2. As unpredictable as it is wonderful, it is an event not to be missed!”
If you’re wondering how, when and where to see Comet A3 — also known as C/2023 A3 (Tsuchinshan-ATLAS) and “comet of the year” — here’s everything you need to know.
Check out my feed every day this week and next for a daily “comet tracker” with sky maps and tips for viewing Comet A3.
Comet A3: When?
Comet A3 will first come closer to the sun and then come closer to Earth. Both of these cases should see it shine brightly for Northern Hemisphere observers.
- Sept. 27-Oct. 3: comet A3 will arrive perihelion — the closest it is to the sun — at about 36 million miles (58 million km) on Sept. 27 and will be visible for about a week before sunrise. During this time, Comet A3 is expected to be at its lowest point and very close to the horizon, so May to be a provocative observationbut worth making. Binoculars are recommended.
- October 12 – October 26: Comet A3 will make its closest approach to Earth at about 44 million miles (71 million kilometers) from Earth on October 12 and become visible after sunset, initially near the horizon but quickly moving away from the sun , so high in the sky. This is when it is expected to be at its brightest.
Comet A3: What time?
From Sept. 27-Oct. 3, Comet A3 will be visible from mid-northern latitudes about 75 minutes before sunrise where you are. It will be best seen at this time, when it is both higher in the sky and in the darkest pre-dawn skies.
From October 12 to October 26, Comet A3 will set in the west after sunset, rising higher above the horizon each evening. Initially it will only be visible for a short window afterwards sunset where you arebut it will climb higher every night, into darker skies, but will dim as it does so.
Uranogram to see Comet A3, also known as C/2023 A3 (Tsuchinshan-ATLAS), one hour before sunrise … [+]
Comet A3: Which direction?
From Sept. 27-Oct. 3, Comet A3 will be visible in the east-southeast direction before sunrise, dipping lower on the horizon each morning before disappearing into bright sunlight.
From October 12 to October 26, Comet A3 will set in the west after sunset, rising higher above the horizon each evening.
Uranogram to see Comet A3, also known as C/2023 A3 (Tsuchinshan-ATLAS), after sunset on October 12, … [+]
Comet A3: Do I need binoculars?
Between September 27 and October 3, Comet A3 may not be bright enough to be easily seen with the naked eye, so having a pair of binoculars handy would be a great idea, just in case.
From October 12 to October 26, Comet A3 is expected to brighten significantly and be visible to the naked eye — the sweet spot is around October 13-16.
Comet A3: What will it look like?
Comet A3 will appear to the naked eye as a small, fuzzy blob with a tail pointing away from the sun.
A comet is made of ice and dust. As it approaches the sun, it heats up slightly. This causes the ice covering its core to turn to gas, creating a coma. This gas – and dust – from the coma trails behind the comet, causes a tail, which can be hundreds of millions of miles long. Comet A3’s tail is about 27 degrees long, the same as the span between your pinky finger and thumb if you held your hand out to the sky.
However, comet A3 – as with many comets – actually has two tails. The bluish tail of the plasma is made of ionized gas, while its other, whitish tail is made of dust.
A photo taken on May 25, 2018 shows the Southern African Large Telescope (SALT) in the South … [+]
How close will Comet A3 get?
There are two points at which a comet is brightest in Earth’s sky — when it is closest to the sun and when it is closest to Earth. On September 27, Comet A3 will reach its perihelion — the closest to the sun — at about 36 million miles (58 million kilometers). This is roughly the distance Mercury orbits the sun. Comet A3 will make its closest approach to Earth on October 12, when it will pass about 44 million miles (71 million kilometers) from Earth.
What is Comet A3?
Comet A3 is a long-period comet from the Oort Cloud, a sphere around our solar system that is home to millions of comets. It has been in orbit for about 80,000 years.
It was discovered in January 2023 by astronomers at China’s Tsuchinshan Observatory and in February 2023 by South Africa’s Last Earth Impact Alert System (ATLAS) telescope.
I wish you clear skies and open eyes.
