Comet ATLAS Probably Won't Be Visible From Earth With the Naked Eye Now As Astronomers Think It's Disintegrating

The comet C/2019 Y4 (ATLAS) has been fading in brightness in the past few days as it approaches the sun, sparking concerns that it could be disintegrating.

The object, which was only discovered on December 29, 2019, has garnered a lot of attention recently, with many in the astronomy community hoping that it would become the brightest comet for more than 20 years.

However, observations conducted in the last few days have indicated the comet may be in trouble on its journey towards our star, somewhat dashing hopes that it might be visible with the naked eye from Earth's Northern Hemisphere by the second half of May.

"[C/2019 Y4 (ATLAS)] brightened quickly until mid-March and showed some promise that it might even reach naked eye visibility in May, however the brightness stalled and then started to decrease steadily," Terry Lovejoy, a well-known amateur astronomer who has discovered six comets, told Newsweek.

"The appearance around the nucleus of the comet has also changed, and is suggesting the comet's nucleus—it's solid core—may either be in the process of fragmenting, shutting down or even disintegrating. Further observations will be needed to determine the exact nature of what is happening," he said.

In fact, astronomers Quanzhi Ye and Qicheng Zhang—from the University of Maryland and Caltech respectively—disseminated a message on The Astronomer's Telegram service on April 6 reporting the "possible disintegration" of the comet as revealed by the public monitoring program carried out by the 0.6-m Ningbo Education Xinjiang Telescope.

"Unfortunately, I feel the most likely scenario is that the comet is at least partly disintegrating so the chances of it being visible to the naked eye are slim," Lovejoy said. "However, astronomers will continue to monitor the comet in the coming weeks to see what it does."

The comet—or what's left of it—is currently located inside the orbit of Mars at a distance of around 95 million miles from Earth. It is currently visible with amateur astronomy equipment in the constellation Camelopardalis ("The Giraffe",) and is best seen in the evening sky, according to Lovejoy.

The comet, which has a very elongated orbit, is scheduled to make its closest approach to Earth on May 23, and the sun on May 31—when it will come within around 23 million miles of our star.

The object was discovered by the ATLAS (Asteroid Terrestrial-impact Last Alert System) robotic astronomical survey system based in Hawaii, a NASA-supported observing program that operates two autonomous telescopes that look for Earth approaching comets and asteroids.

The reason for the excitement over C/2019 Y4 (ATLAS) is that comets with the potential to become obvious naked eye objects are rare, according to Don Yeomans, a retired NASA astronomer specializing in comet and asteroid orbits and observations.

In fact, it has been more than two decades since the last spectacularly bright comet—Hale-Bopp—passed by Earth in 1997. However, it would not be unusual for C/2019 Y4 (ATLAS) to disintegrate as it approaches our star—a behavior that is not uncommon for comets that have not been in the inner solar system before.

"Comets are fragile constructs of mostly ices and dust and some have been known to break up and disperse near the sun," Yeomans told Newsweek. "As the famous astronomer Fred Whipple used to say, 'both comets and cats have tails—and both are unpredictable.'"

"The comet, or its fragments, will be visible as it continues to approach the sun but it may not be a naked-eye spectacle. Comets are unpredictable. Whether or not the comet becomes a naked-eye spectacle, a small army of amateur astronomers will be watching with telescopes and binoculars to see if the comet survives its passage by the sun, he said.