Is the comet still visible tonight? Yes! Comet Tsuchinshan-ATLAS (also called C/2023 A3 and Comet A3) is visible now in the west after sunset from the Northern Hemisphere, but you’ll need to know exactly when to look, where it is and how to find it.
It may be a few nights past its brightest and best, but tonight — Friday, Oct. 18 — sees it rising ever higher into a darker sky, making it both more prominent and visible for much longer than earlier this week.
The comet is now racing away from the sun and Earth, today reaching over 60 million miles distant, but it’s higher position in the sky should make it easier to see, with mountains, trees and buildings no longer in the way. If you find it, here’s how to photograph it.
Here’s exactly when and where you need to look to see the comet with your naked eyes on Friday, Oct. 18.
Note: times and viewing instructions are for observers at mid-latitudes in the Northern Hemisphere. Check the exact time of sunset where you are and the comet’s setting times on Stellarium Web for times accurate for your exact location.
How To Locate Comet Tsuchinshan-ATLAS: Friday, Oct. 18
Position: west, 40 degrees from the sun in Serpens
Time: 45 minutes after sunset where you are
Magnitude: +1.5
Comet’s distance from the sun: 62.6 million miles (100.8 million kilometers)
Comet’s distance from Earth: 52 million miles (83.7 million kilometers)
This evening, the comet will be visible high above the western horizon about 45 minutes after sunset, setting around two hours 25 minutes later. That’s means it will be in the sky for about 15 minutes longer than on Thursday.
Look west for bright Venus above the southwest and Arcturus above west-northwest, the latter a bright, twinkling, reddish star at the bottom of the Y-shaped constellation Boötes. It’s hard to mistake. The comet will be above a point roughly halfway between them, making a triangle shape — or a coat-hanger with comet Tsuchinshan-ATLAS as the hook.
A 96.4%-illuminated waning gibbous moon will rise while you look for the comet, so take the time to swivel 180 degrees to watch it rise in the east draped in orangey hues. A beautiful sight!
Although both the comet and the rising near-full moon can be seen with the naked eye, any pair of binoculars will give you a superb view.
When Will The Comet Disappear?
How long can you see Comet Tsuchinshan-ATLAS for? We’ve been lucky with comet Tsuchinshan-ATLAS. It got closest to the sun on Sept. 27 and appeared in the Northern Hemisphere’s post-sunset evening sky while still bright, but it won’t last long. So if you have a clear sky, look west after sunset. There’s no time to waste!
It’s been visible to the naked eye until now, but around Saturday, Oct. 19 or Sunday, Oct. 20, it will fade quickly, so don’t expect to see it much later than that this month unless you use binoculars or a small telescope.
According to Sky & Telescope, you won’t see it with the naked eye on Halloween — Oct. 31 — though it will probably remain visible through binoculars until early November.
Check my feed every day this week and next for a daily “comet tracker” with sky-charts and tips for viewing the comet.
Wishing you clear skies and wide eyes.
