A newly discovered comet may provide us with a sky treat when it passes by Earth at the end of the year. In fact, it may even become the brightest comet of the year. Comet Leonard (or C/2021 A1) was first spotted on January 3rd by astronomer Gregory J. Leonard at the Mount Lemmon Observatory in Arizona.
When it was first discovered, the comet was exceptionally dim with a magnitude of 19 (approximately 160,000 times dimmer than the faintest stars we see in the sky with the naked eye) but that was because it was close to Jupiter’s orbit of about 5 astronomical units (AU) from our sun (the distance of Earth to the sun is equal to one AU).
When the comet was first spotted, it was beginning to feel the effects of the sun’s rays and slowly started transforming out of its completely frozen state with some pictures even capturing what appeared to be a tail on it.
Since it has an exceptionally long, flat elliptical orbit that can bring the comet as far away as 3,500 AU from the sun, it isn’t a “new” comet that came from the Oort Cloud (those comets have never traveled near the sun before). Instead, it is believed that it actually flew past the sun on at least one occasion around 70,000 years ago. This means that it wouldn’t have “new” materials on its surface like frozen carbon dioxide, nitrogen, and carbon monoxide that would vaporize and end up not being as bright.
Based on how bright the comet currently is, it is believed that it will be bright enough by the year’s end to possibly be seen without any optical aid (maybe a brightness magnitude of 4).
Those who are willing to wake up a couple of hours before the sun rises, they’ll be able to see Comet Leonard in the lower portion of the east-northeast sky (traveling through the constellations Coma Berenices, Boötes and Serpens Caput) during the first two weeks of December. At that point, the comet will be visible with a small telescope or binoculars, and hopefully with the naked eye as well. It will make its closest approach to Earth on December 12th at a distance of 21.7 million miles (34.9 million kilometers) from us.
In the second half of December, the comet will approach the sun so the light of dawn will obstruct our view of it; therefore, the best time to see it would be in the very early morning hours from early to mid December. It will make its closest approach to the sun on January 3, 2022 at a distance of 57.2 million miles (92 million kilometers).
However, as we all know, comets can be unpredictable, but we’ll find out more information as the year goes on and Comet Leonard gets closer.
An image of Comet Leonard’s trajectory around the sun can be seen here.