Comet McNaught over Big Swamp, Eyre Peninsula. South Australia in 2007.
The ATLAS survey telescope has detected a comet approaching the Sun just as sky watchers and astronomers prepare to view and photograph Comet C/2023 A3 (Tsuchinshan-ATLAS), which should be visible to the naked eye after sunset helium for a few weeks starting around October. 9.
The new comet, originally named A11bP7I and now named C/2024 S1 (Atlas), appears to be unusually large and could become a “significant unaided object by late October,” according to SpaceWeather.com.
How, When and Where to See Comet C/2024 S1 (Atlas)
C/2024 S1 (Atlas) is expected to make its closest approach to Earth on October 23 and perihelion with the sun – the closest it will ever come to our star – just five days later on October 28. This latter date appears to be the best time to observe it, because it can shine at magnitude -8.3. This is extremely bright, brighter even than Venus, the brightest object in the sky besides the sun and moon.
The Best Times to See Comet C/2024 S1 (Atlas)
- From October 24 to 28, C/2024 S1 (Atlas) should be best seen from the southern hemisphere and equatorial regions before sunrise. This is when it could increase in brightness and become visible to the naked eye, according to StarWalk. It will be closer to the sun each morning during this time.
- From October 29 to 31, C/2024 S1 (Atlas) was visible from the northern hemisphere after sunset, moving further away from it each night.
However, there is an important caveat. Comets are unpredictable and can break up as they approach the sun. The critical date for C/2024 S1 (Atlas) is 28 October perihelion. It must survive to become a genuinely bright object and become visible to anyone in the northern hemisphere.
Comet C/2024 S1 (Atlas) is a long-period comet from the Oort Cloud — a sphere around our solar system that hosts millions of comets — and was discovered on September 27, 2024, by astronomers on the ATLAS survey, in Hawaii.
How, When and Where to See Comet C/2023 A3 (Tsuchinshan-ATLAS)
C/2023 A3 (Tsuchinshan-ATLAS) — also known as Comet A3 — has already perihelion with the sun on September 27th and will make its closest approach to Earth on October 12th. A night or two before this last date seems to be the best time to observe it, because it can be bright enough to be seen with the naked eye.
Best times to see Comet C/2023 A3 (Tsuchinshan-ATLAS)
- On October 12, C/2023 A3 (Tsuchinshan-ATLAS) should be best seen from the Northern Hemisphere and equatorial regions after sunset. It will shine near a 9 percent waning crescent moon and Regulus, the brightest star in the constellation Leo, “the Lion,” before gradually fading as it moves away from Earth over the next 10 or so nights.
For C/2023 A3 (Tsuchinshan-ATLAS), the prospects of being distinct are more certain because it has already survived perihelion. The favorable position means that its dusty tail will likely reflect sunlight due to a phenomenon called “forward scattering” that sends reflected sunlight in the direction of Earth.
Comet C/2023 A3 (Tsuchinshan-ATLAS) is also a long-period comet from the Oort Cloud and visits the inner solar system approximately every 80,000 years. It was discovered in January 2023 by astronomers at China’s Tsuchinshan Observatory and South Africa’s Ground-Based Asteroid Impact Early Warning System (ATLAS) telescope.
I wish you clear skies and open eyes.
