Comet Tracker For Tuesday: Tonight Is Your Last Best Chance To ...

NASA astronaut Matthew Dominick captured this timelapse photo of Comet C/2023 A3 (Tsuchinshan-ATLAS) ... [+] from the International Space Station as it orbited 272 miles above the South Pacific Ocean southeast of New Zealand just before sunrise on Sept. 28, 2024. At the time, the comet was about 44 million miles away from Earth.

If you’re wondering how to locate comet Tsuchinshan-ATLAS tonight, here’s everything you need to know.

The best naked eye comet since comet NEOWISE — also known as the “lockdown comet” because it appeared in July 2020, during the Covid pandemic — comet Tsuchinshan-ATLAS (also called C/2023 A3 and Comet A3) is currently visible into the night sky immediately after sunset.

Tonight, Tuesday, Oct. 15, is the second of the two best opportunities to see the comet at its brightest and best from the northern hemisphere. Given that it won’t return for around 80,000 years, it’s definitely worth a look.

When and where to see the bright Comet Tsuchinshan-ATLAS between Oct. 11 through Oct. 21 as it rises ... [+] higher into the sky and becomes more visible against darker skies.

Comet Tsuchinshan-ATLAS exited the sun's glare late last week and is now positioned rather conveniently for a post-sunset view. On Saturday, it got to within 44 million miles (71 million kilometers) as it reached its closest to Earth, but was tricky to see because it was so close to the sun.

Tonight the comet will be a huge 30 degrees from the sun, which means it will be relatively easy to see — clear skies allowing — fairly high up in a dark sky.

However, you’ll need a good, clear view of the western horizon to see it after sunset. The lower you can see to the horizon, the longer your view of comet Tsuchinshan-ATLAS. 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 Tuesday, Oct. 15.

Exactly where to see comet Tsuchinshan-ATLAS, also called C/2023 A3 and Comet A3, after sunset on ... [+] Tuesday, Oct. 15, 2024.

Position: west, 30 degrees from the sun in Serpens

Time: 45 minutes after sunset where you are

Magnitude: +0.9

Comet’s distance from the sun: 57.4 million miles (92.4 million kilometers)

Comet’s distance from Earth: 46.4 million miles (74.7 million kilometers)

This evening, the comet will be visible close to the western horizon about 45 minutes after sunset amid fading twilight, setting around an hour and 40 minutes later. That means it will be in the sky for about 20 minutes longer than on Monday.

One thing to note is that the waxing gibbous moon will be bright, 97%-lit, which will make the night sky less than dark. However, that shouldn’t interfere too much with comet-spotting since the moon will be shining in the south and comet is low in the west.

ForbesYour Ultimate Guide To Seeing The Comet Every Night This Week — Before It FadesBy Jamie Carter

In a clear sky you’ll be able to use a planet and a star to locate the comet. Find the bright planet Venus and the bright star Arcturus; the comet will be just above halfway along an imaginary line drawn between them. The comet will be roughly two fists to the upper right of Venus (if seen from the northern U.S.) or to the right of Venus (if seen from the southern U.S.), according to Sky& Telescope. “As twilight turns to night, the comet will remain in view, its long, straight tail pointing up from the horizon,” it adds.

Tonight sees the comet move from the constellation Virgo into Serpens, a small and indistinct shape of eight stars that resemble a snake. Next to Serpens is Ophiuchus, “the snake handler,” which the comet will move into on Saturday, Oct. 19.

On Tuesday, Oct. 14, 2024, Comet Tsuchinshan-ATLAS will pass just 1.4 degrees from a globular ... [+] cluster called Messier 5 (M5 and NGC 5904) in the constellation Serpens.

All you need to see the comet is your naked eyes, but any pair of binoculars will give you an incredible view.

However, if you do have a telescope, there’s a bonus sight available, according to BBC Sky At Night magazine.

As you view it after sunset, comet Tsuchinshan-ATLAS will be just 1.4 degrees (the width of your pink finger held at arm’s length) below the M5 globular cluster in the constellation Serpens. Remarkably, comet 13P/Olbers will also be visible.

However, that mass of 13 billion-years-old stars and the second distant comet won’t be visible to the naked eye. If you want to see these two objects, as well as comet Tsuchinshan-ATLAS, through a huge telescope, tune in at 17:00 UTC (1:00 p.m. EDT) to a livestream from The Virtual Telescope fro Italy.

Messier 5 or M5 (also designated NGC 5904) is a globular cluster in the constellation Serpens.

The comet is shining at around magnitude +1 but changing each night. “It passed its brightest point this past Wednesday while 4 degrees from the sun when its head was about as bright as Venus at magnitude -4, albeit with that light spread over an area of sky nearly the size of the moon,” said astronomer Dr. Qicheng Zhang of Lowell Observatory in Flagstaff, Arizona, who has been monitoring the comet, in an email. “That made it very hard to see despite being the brightest comet in over a decade. It's now fading, but also becoming much easier to see and more visually prominent in the evening as it moves away from the sun.”

Discovered in January 2023 by astronomers at China’s Tsuchinshan (Purple Mountain) Observatory and the following month by South Africa’s Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope, comet Tsuchinshan-ATLAS is a long-period comet from the Oort Cloud, a sphere around our solar system that's home to millions of comets. It enters the inner solar system to orbit the sun once every 80,000 years.

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.