Get Ready: Comet C/2024 S1 (ATLAS) May Outshine Venus in Late October 2024!

~7 min

A new candidate for the brightest comet of the year and the brightest Kreutz sungrazer since 1965 has just been discovered. You can already track it with the free Sky Tonight and Star Walk 2 apps. Just type C/2024 S1 in the search bar and tap the target icon to find it in your sky. In this article, we'll give you all the latest details about this remarkable comet.

Contents

Quick facts about Comet C/2024 S1 (ATLAS)

  • Official name: C/2024 S1 (ATLAS)
  • Former name: A11bP7I
  • Type: non-periodic Kreutz sungrazer comet
  • Closest approach to Earth: October 23
  • Predicted brightness at the closest approach: mag 7.0
  • Perihelion: October 28 (best time to observe 🌟)
  • Predicted brightness at perihelion: mag -8.3
  • Visible from: Southern Hemisphere (before perihelion), Northern Hemisphere (after perihelion)

Comet C/2024 S1 (ATLAS) tonight

Is Comet C/2024 S1 (ATLAS) visible in the sky right now?

Currently, C/2024 S1 (ATLAS) has a magnitude of around 12, visible through small telescopes. The comet is located in the constellation Hydra, easier to view from the Southern Hemisphere before dawn. For Northern Hemisphere observers, it sits lower on the horizon.

C/2024 S1 (ATLAS) is now located about 1 AU from the Sun and 1.3 AU from Earth. Its tail spans about 2 arcseconds.

How to locate Comet C/2024 S1 (ATLAS)?

To track C/2024 S1 (ATLAS), you can use the free Sky Tonight or Star Walk 2 apps:

  • Type C/2024 S1 into the search bar.
  • In Sky Tonight, tap the target button next to the comet's name. The app will show you the comet's location on the sky map.
  • In Star Walk 2, simply tap the comet's name. The app will show you the comet's location on the sky map.
  • For real-time tracking, point your device at the sky and follow the white arrow.
C/2024 S1 (ATLAS) in the sky
Locate C/2024 S1 (ATLAS) in your sky right now with the help of Star Walk 2 or Sky Tonight.

Comet in October 2024: when and where to see?

Best time to see Comet C/2024 S1 (ATLAS): how bright will it get?

In the Southern Hemisphere, the best time to catch the comet is in the days before perihelion on October 28. In the Northern Hemisphere, the comet may be visible for a few days after perihelion if it survives. It can also develop a large curved tail, as happened with comet C/1965 S1 (Ikeya-Seki).

Comet C/1965 S1 (Ikeya-Seki)
Comet C/1965 S1 (Ikeya-Seki) captured on October 30, 1965, by James W. Young (TMO/JPL/NASA).

The most exciting part is how bright Comet C/2024 S1 will get in perihelion. The current positive forecast is that it could become as bright as magnitude -8.3 on October 28, easily visible even in a pre-dawn sky! For comparison, the brightest dot in the night sky, Venus, is only -3.9 magnitude.

Comet C/2024 S1 (ATLAS) brightness
In the best-case scenario, Comet C/2024 S1 (ATLAS) will reach a magnitude of -8.3 on October 28. The chart is based on the data by astro.vanbuitenen.nl on October 3.

Keep in mind that comet behavior is naturally unpredictable. As more data comes in, the forecasts will be adjusted, so check back here for the latest updates. The unpredictability of comets – whether they disappoint or amaze – is part of what makes them so fascinating!

In the meantime, keep an eye on Tsuchinshan-ATLAS, another bright comet putting on a spectacular show. You can read more about it in our dedicated article.

Path of Comet C/2024 S1 (ATLAS) in October 2024

Here’s what to expect from Comet C/2024 S1 (ATLAS) in October:

C/2024 S1 (ATLAS) in October 2024
C/2024 S1 (ATLAS) trajectory in October 2024. The image is based on data from the Sky Tonight app.

October 4-15: Southern Hemisphere telescope visibility

At a magnitude between 12 and 10, Comet C/2024 S1 (ATLAS) is visible through telescopes in the late-night sky in the Southern Hemisphere. C/2024 S1 is about 40 degrees from the Sun in the sky.

Key dates:

  • October 4: passes the star Alphard (mag 2.0)
  • October 7: passes the star Zhang (mag 4.1)
  • October 15: enters the constellation Crater

October 16-23: approaching Earth

The comet brightens to a magnitude of 10 to 7, becoming visible with small backyard telescopes late at night in the Southern Hemisphere. C/2024 S1 reaches the elongation from 35 degrees to 20 degrees from the Sun in the sky.

Key dates:

  • October 20: enters the constellation Corvus
  • October 22: passes the star Gienah (mag 2.6)
  • October 23: reaches a magnitude of 7.0 at its closest point to Earth (0.88 AU), and passes the star Algorab (mag 2.9)

October 24-28: approaching perihelion

The comet’s brightness increases rapidly, reaching between magnitude 6 and -9 as it nears the Sun. It is visible before dawn in the Southern Hemisphere and potentially from the southern parts of the Northern Hemisphere. It may become visible to the naked eye. C/2024 S1 approaches the Sun, within 2 degrees of it at perihelion.

Key dates:

  • October 25: enters the constellation Virgo, where the Sun is also located
  • October 26: passes the star Spica (mag 1.0)
  • October 28: reaches its closest point to the Sun (0.306 AU) with a peak brightness of -8.3, but will be hard to spot due to the Sun's glare.

October 29-31: after perihelion

If the comet survives its close encounter with the Sun, it will move away, shining brightly and growing a longer tail. C/2024 S1 will move from a distance of 3 degrees to 11 degrees from the Sun in the sky on these dates. This will be the best time to observe C/2024 S1 (ATLAS) in the Northern Hemisphere.

Key date:

  • October 31: passes the star Spica (mag 1.0)

More facts about Comet C/2024 S1 (ATLAS)

C/2024 S1 (ATLAS) discovery

Comet C/2024 S1 (ATLAS) was discovered on September 27, 2024, by the ATLAS survey in Hawaii. It was given the temporary designation A11bP7I while awaiting official confirmation. On October 1, it has been confirmed and officially named C/2024 S1 (ATLAS).

C/2024 S1 (ATLAS) name

The name of the comet contains data about where and when the comet was first seen:

  • The letter C indicates a non-periodic comet – comets of this type originate from the Oort cloud and may pass through the Solar System only once or take from 200 to thousands of years to orbit the Sun;
  • 2024 S1 means the comet was discovered in 2024, in the second half of September (this corresponds to the letter S in the IAU comet naming system), and was the first such object discovered in this period;
  • ATLAS means the discovery was made using the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope.

Comet type – the Kreutz sungrazer family

This comet is thought to belong to the Kreutz sungrazer family, a group of comets that pass very close to the Sun. The comets of this type are thought to be fragments of one large comet that broke up several centuries ago.

Historically, Kreutz sungrazers, such as Ikeya-Seki (1965) and Lovejoy (2011), have often become particularly bright, visible even in daylight. If C/2024 S1 (ATLAS) follows a similar brightening trend, it could become the brightest Kreutz sungrazer comet since 1965.

Its closest approach to the Sun, or perihelion, is expected on October 28, 2024. Interestingly, this date is just a week after the perihelion of the famous Ikeya-Seki comet in 1965, which means visibility conditions could be very similar. However, C/2024 S1 (ATLAS) is expected to be slightly dimmer.

Concerns about C/2024 S1 (ATLAS)

While the excitement is high, there are some concerns about the fate of C/2024 S1 (ATLAS). Here are some of them:

  • It may break apart at perihelion

Kreutz sungrazers often break apart as they approach the Sun, due to the intense heat at these extremely close distances. This is a possibility for C/2024 S1 (ATLAS), especially if it turns out to be a smaller comet.

  • It could fade

Some observers speculate that C/2024 S1 (ATLAS) might be a smaller fragment of the Kreutz family that’s currently in an outburst, similar to previous sungrazers like C/1945 X1 (du Toit) and C/2012 E2 (SWAN). Both faded as they neared the Sun after initially showing bright activity.

Despite these uncertainties, Kreutz sungrazers have historically been some of the most spectacular comets. Will C/2024 S1 (ATLAS) follow in their footsteps? We’ll have to wait and see! And while you wait, check out our fun quiz to learn more about famous Great Comets from history!

Great Comets
What do comets have to do with Cognac and the American Civil War? 🥃A lot more than you'd think! Our quiz is packed with fun facts about the Great Comets. Get ready for a fun ride through time with these flashy space travelers! ☄️
Take the quiz!

C/2024 S1 (ATLAS) Conclusion: a new bright ATLAS comet for October 2024?

Comet C/2024 S1 (ATLAS), discovered on September 27, 2024, could become the brightest naked-eye comet of the year and the brightest Kreutz sungrazer since 1965. At its peak, it could reach a magnitude of up to -8.3. Don’t miss your chance to witness it! The comet can already be tracked using Sky Tonight and Star Walk 2. Also, be sure to check out our article on Tsuchinshan-ATLAS, another comet expected to light up the skies in October. Two comets, one month – catch them both!

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