UPDATED 2024 Oct 10 0915 CDT
Manitobans will have a chance to catch a comet this October (2024). Comet C/2023 A3, a.k.a. Comet Tsuchinshen-ATLAS, will be visible in our evening sky beginning about October 11. This article will describe how to see the comet yourself and provide a day-by-day description of its period of best visibility.
Based on its behaviour up until October 10, I am tempering my expectations for this comet a bit. It’s still going to be a great sight, but it won’t be as bright as some have been predicting. The comet will likely need binoculars or a camera to spot it while it’s in the bright twilight over the week of Oct 11-16.
However, the comet’s tail is longer than expected, stretching nearly 45 degrees across the sky – that is about the distance from the horizon to halfway overhead. So even though the comet’s head sets soon after the sun, its tail might be visible sticking up above the horizon much later, when the sky has gotten darker. You’ll still want dark skies free of city lights, and binoculars or a camera, to get the best view.
(Note: While written for Manitoba, this article works for anyone in southern Canada, or at roughly the same latitude of 40-50 degrees North anywhere in the world. So, much of Europe and Asia will have similar views.)
(Second note: Comets are notoriously unpredictable. They can undergo outbursts that make them brighten 100x in an hour; they can also fragment or fizzle out without any obvious explanation. This article presents the best predictions available at the time of writing, and will be updated as conditions change.)
(Third note: While another potentially bright comet, Comet C/2024 S1 (ATLAS), was discovered recently, this comet will likely not be visible from Manitoba.)