Your Last Best Chance to See Comet A3 is Today, October 17th
My friend Krystle holds the comet in her hands on the night of October 15th, 2024. Single Exposure.
When To See the Comet
Comet A3, more formally known as C/2023 A3 or Comet Tsuchinshan-ATLAS, is now fading from our view, and it’s not known exactly how many more days we’ll be able to see it with the naked eye or with the aid of binoculars, telescopes, or cameras. That makes tonight, Thursday, October 17th, your best last chance to see it. With a really good eye you might be able to see A3 starting around a half hour after sunset. From there it will become more visible as the sky continues to darken, but then it sinks below the horizon at about 2.5 hours after sunset. I’ll update all of the information here in the coming days to reflect the latest information.
Where To See the Comet
The comet is best viewed and photographed far away from all artificial light. Get as far outside the city as you can. Just as they do for your every night star gazing, city lights will reduce visibility, and the comet is already quite faint, so it will be much harder to see in or near cities. I have seen some pretty impressive photos of the comet over cities though, so if you want to go for something like that just know it will be more of a challenge to see and capture it. To find the comet in the sky, you can use astronomy apps to guide you (I’ll be adding links to ones that will work well soon!), or take a photo on your camera or on your phone using the night mode. You can find guidance on taking a photo as a search aid in the photography tips below. Though you can see the comet with the naked eye once it’s dark enough outside, it is fairly faint at first. If you don’t have an astronomy app, you can follow these steps to get a general idea of where the comet is in the sky:
1. Hold out your arm and align the bottom of your fist with the horizon at the same place the sun set.
2. Stack your other fist on top of the first fist, with the bottom of the second fist touching the top of the first fist.
3. Repeat this stacking process two more times, so that you have a total of four fists stacked on top of each other.
4) The top of the fourth fist is the area to start looking for the comet, about 45 minutes after sunset.
Comet A3 approaches a happy little cloud on the night of October 14th, 2024. Single Exposure.
Viewing Tips:
☄️ Let your eyes adjust to the darkness. Turn off all of your lights and devices and give your eyes a few minutes to adjust and you will be able to see the comet and stars more easily. Looking at your phone screen even for a second will throw your eyes off and you’ll need time to readjust. I recommend keeping your phone screens off altogether, but if you must use it, set the brightness as low as it will go.
☄️ Use binoculars or a telescope for an enhanced experience. Remember, the comet is not easy to see with the naked eye. Given most of the photos you’ve probably seen of it, including the ones on this page, you may think of it as a prominent night sky object, but in reality it appears much fainter, and can be tricky to spot. Look for a fuzzy line in the sky, similar to airplane contrails, but quite faint.
Comet A3 approaches the horizon beside Balanced Rock, in Arches National Park, on October 12th, 2024. Single Exposure.
Photography Tips (Thursday, October 17th)
☄️ Your spot should have a nice view to the West. You don’t necessarily need a low horizon, however it’s still important to consider the terrain. For example, if you go to the base of a tall mountain hoping to capture the comet over it, it may not work out. Look for a place with a relatively clear and wide view of the sky to the West.
☄️It’s likely you’ll be able to capture the comet and see it in a photo before you can see it with the naked eye. Using your camera is a nice way to find the comet, unless you are using an astronomy app to more easily locate it. After setting up your camera on a tripod, point it to the west, focus to infinity, and an exposure long enough to see some stars. Check the results on your screen to see if you can spot the comet.
☄️ Be prepared for the window of time you’ll have to capture it. On Thursday, October 17th, you’ll only be able to see it for about 2.5 hours, and there’s an even smaller window within that for ideal viewing.
☄️ As with other astrophotography, it’s a good time to experiment with settings and check the results as you go. There are no settings that will work for all photos, considering all of the variables that come into play, but as a starting point you could try your lowest aperture, 1600 ISO, and a 3 second exposure. Check the image and then tweak ISO and shutter speed to your liking.
☄️ The moon is now full, which will diminish visibility of the comet, but can also be used to illuminate the landscape. Use this to your advantage by searching for an interesting landscape to include in your photo as the comet approaches the horizon.
My friend Krystle holds comet A3 in her hands on the night of October 15th, 2024. Single Exposure.
I hope this helps you to be able to witness and\or photograph the beautiful A2 comet. Remember, once it’s gone, you won’t have an opportunity to see it again for about 80,000 years! Let me know if you were able to see it.
Disclaimer: I stayed up most of the night to prepare all these tips and information since the 17th might be our last good chance to see the comet. I didn’t have time to do all the research I wanted to in regards to the comet, and I’m not entirely sure how relevant the information presented here is for the Southern Hemisphere, or even other continents outside of North America. I will be doing some additional research after I wake up though, and I’ll add supporting information as I find it.
