For stargazers who were looking forward to getting outside on the night of May 31st to view Comet Atlas (also known as C/2019 Y4) flying past Earth, there has been an unfortunate development – the comet has officially broken apart.
Just a few weeks ago, experts were predicting that the comet could potentially be as bright as the moon when making its closest approach to the sun, passing by Earth at a distance of just 23.5 million miles.
Astronomers discovered the comet in the Ursa Major constellation on December 28, 2019 by using the Asteroid Terrestrial-impact Last Alert System (or ATLAS) system in Hawaii. And in an incredibly short amount of time, it brightened up drastically. In December, the comet was around a 20th magnitude, meaning that it was about 398,000 times dimmer than the majority of stars we see with the naked eye at night. However, it was predicted that by the time it would pass by Earth at the end of May, its brightness could increase by almost 11 magnitudes (the full moon is usually at 14 magnitudes).
There was, however, a chance that it could fall apart before getting close to us and that’s exactly what happened as it’s not in one piece anymore. In an email statement issued on April 12th, Gianluca Masi, who is an astrophysicist as well as the founder and director of the Virtual Telescope Project in Italy, said that the comet “has shattered both its and our hearts.” “Its nucleus disintegrated, and last night I could see three, possibly four main fragments,” he confirmed. He posted pictures of the broken-up comet which can be viewed here.
When comets break up, it’s usually because they spend the majority of their time in the outer part of the solar system which is extremely cold, so when they get close to the sun, they fall apart. This is extremely disappointing news especially for those living in the Northern Hemisphere, as this would have been the first time in several years that a passing comet would have made a spectacular show in the night sky. I guess we’ll have to wait for the next great comet to make its appearance – hopefully at a safe distance away.