ATLAS Crumbles as New SWAN Comet Stirs Excitement

You gotta love a comet. Wait. Let me rephrase. You gotta be crazy to love a comet. Their unpredictability can drive us nuts. We expect them to brighten as predicted but then they'll stall or even bust apart and dissipate. But it's that very unreliability that gives them their charm and affirms that change in the heavens is as certain as change on Earth. Not only that but new comets can come out of nowhere — exactly what happened with the exciting discovery of Comet SWAN (C/2020 F8). Sit tight. We'll touch on this new object in just a moment.

We'll begin with Comet ATLAS, discovered last December, was predicted to brighten to naked-eye visibility in May. Some astronomers cautioned at the time that it might also break into pieces and fade away as it approached the sun. Guess what happened? Earlier this month it began to shed fragments from its icy nucleus. While had been a spectacular brightening trend rapidly reversed, and ATLAS began to fade. The fragments drifted apart, spewing dust and ice, to create a train of of fuzzy nuggets inside the comet's head.

Although the comet is still visible in 6-inch and larger telescope as it wriggles across the northern sky it's faded from magnitude 8 to 9.5. Instead of getting brighter ATLAS appears to be headed toward oblivion. While part or parts of the comet may survive its May 31st perihelion (closest approach to the sun) we'll probably have to eat our hopes of seeing it with the naked eye or binoculars. In the past week I've examined it regularly in my 15-inch telescope. It looks like a soft, misty patch of haze with a stretched-out core. At 400x I see hints of the fuzzy fragments clearly shown in the photo above.

If you want to track down Comet ATLAS yourself, use this map from Sky & Telescope. Warning — it's not particularly bright. Likewise, the comet is tracking across the large, dim constellation Camelopardalis the giraffe which has no bright stars to serve as easy guides. Still, with determination and the right instrument you'll find it. Look soon though! The best viewing time is at the end of evening twilight when it first gets dark. The comet is located about halfway up in the northwestern sky.

Just as ATLAS is dissipating another comet has come to the rescue. Named SWAN (C/2020 F8) — after a specialized camera on the orbiting Solar and Heliospheric Observatory (SOHO) — it was discovered earlier this month by Australian amateur Michael Mattiazzo. Mattiazzo spotted it while browsing through SOHO images posted online. The comet is already 8th magnitude and viewable in binoculars but only for southern hemisphere observers at the moment. Come early May it will ease into the dawn sky in the constellation Pisces then move rapidly eastward through Triangulum and Perseus as it brightens from about magnitude 6 (naked-eye limit) to 3.5! From mid-May into June will be prime time viewing for northern hemisphere observers when the comet will be located low in the northeastern sky at the start of dawn.

Of course there are caveats. Throughout its run, SWAN will never rise very high before the light of dawn interferes. That means you'll have to be out at the right time to see it at its best ... and carry along a pair of binoculars for assistance. I'll help with updated maps, news and occasional humorous anecdotes in the weeks ahead. Should the comet live up to predictions it will be dimly visible at dawn without optical aid and a fine sight in binoculars.

Meanwhile, Comet PanSTARRS (C/2017 T2) has been plugging across the northern sky for weeks. Ugh! It's also in Camelopardalis — thankfully not for long. The comet inches closer to the bucket of the Big Dipper each night which will make finding it much easier.

From a dark sky PanSTARRS is visible as a faint, fuzzy blob in 10x50 binoculars. Through a 6-inch scope you'll see a round, misty glow with a brighter center and might even glimpse the central pinpoint of light called the false nucleus (the real one is very tiny and obscured by dust). Larger telescopes reveal a short, brush-like tail pointing southeast.

PanSTARRS will remain around magnitude 8 through the remainder of April and May, presenting many opportunities for you to grab a look. Best viewing time for late April is during the first half of the night from the onset of darkness until around midnight. Like the two ATLAS comets it's also in the northwestern sky and up all night from many mid-northern latitude locations.

Oh, and that's not the end of it. A reader reminded me that a second Comet ATLAS (C/2019 Y1) has stubbornly refused to fade away despite predictions to the contrary. I checked it out last night (April 15-16) and was surprised to see it binoculars next to the W of Cassiopeia low in the northern sky at nightfall. Just a tiny ball of fuzz, but in the telescope it was bright — magnitude 8.5 with a small, dense coma and faint tail pointing north. I even saw hints of green!

ATLAS Y1 was discovered in December 2019 and hugged the horizon until recently. Watch for it to sail across the northern sky toward the Big Dipper in the coming weeks while slowly fading. It passes just 6.5 from the North Star on May 1st. While faintly visible in binoculars a 6-inch telescope will show as a glowing blob of light.

With all the exciting news about comets I don't miss a clear night anymore. Sometimes nature just piles it on!