A newly discovered comet named ATLAS is on track to become one of the brightest comets to grace our night skies since Hale-Bopp in 1997.
Officially known as C/2019 Y4, the comet was nicknamed ATLAS in honor of the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope that spotted it in late December 2019. As the comet has tracked further into our solar system and towards a scorching rendezvous with the sun, it has been rapidly brightening.
"Right now the comet is releasing huge amounts of its frozen volatiles (gases)," Karl Battams of the Naval Research Lab in Washington, D.C., told SpaceWeatherArchive (SWA). "That's why it's brightening so fast."
Since its discovery on Dec. 28, 2019, the comet has brightened quickly to that of an eighth-magnitude star. (It helps to know that an object's brightness is measured by apparent magnitude. The brighter an object appears, the lower its magnitude, with the brightest objects having negative magnitudes.) While not yet visible to the naked eye, medium-sized telescopes should be able to pick out the comet under dark skies, EarthSky says. By May, when it makes its closest approach to the sun, ATLAS may brighten to anywhere from visible magnitude +1 to -5.
Will you be able to spot ATLAS?
It's important to remember that comets are notoriously fickle phenomena. Every trip around the sun vaporizes frozen volatiles on the comet's crust that result in the formation of a glowing coma of gas around the nucleus. Solar wind then stretches this into a tail, with some extending for millions of miles from the comet's head.
In some instances, comets that scientists expect to brighten remain stubbornly immune to the heat of the sun. Others, weakened by repeated flybys of the sun, break up and fade away. While ATLAS will clear Earth by a comfortable 72 million miles on May 23, its trajectory is expected to take it within only 23 million miles of the sun one week later on May 31.
Battams is not optimistic ATLAS will survive such a close encounter.
"My personal intuition is that Comet ATLAS is over-achieving, and I wouldn't be surprised to see it start to fade rapidly and possibly even disintegrate before reaching the sun," he told SpaceWeatherArchive.
Those who would prefer the glass half full when it comes to witnessing the spectacular beauty of a comet in the night sky can yet hang their hopes on one intriguing piece of information. According to calculations by NASA/JPL, ATLAS appears to share a near-identical 6,000 year orbit with the Great Comet of 1844 — and it's possible it may be a fragment of that comet.
Could this new visitor potentially rival other great celestial sun-grazers in human history?
Where to look
Comet ATLAS is in a favorable position for northern latitudes and will appear more than halfway up in the north-northwest sky after nightfall. According to LiveScience, you should be able to find it with a telescope through April by looking in the constellation Camelopardalis the Giraffe. After April, fingers crossed that ATLAS will simply draw your eye as it glows in the May night sky.