Spotting Leonard: A Guide to Identifying the Year's Most Brilliant Comet

The time has arrived for stargazers to gaze upward and catch a glimpse of comet Leonard. Here’s how you can locate this enormous sphere of ice and debris.

Senior research specialist Greg J. Leonard uncovered the comet that now bears his name on January 3, from the Mount Lemmon Observatory in Arizona. Comet Leonard (or more formally, C/2021 A1) is headed towards the inner solar system, and, as is customary of incoming comets, it's progressively shedding its surface materials into space. Leonard's closest approach to the Sun - its perihelion - will occur on January 3, 2022, after which it will begin its lengthy journey to the outer solar system.

The timeframe for observing Leonard without highly advanced astronomical equipment is now open. Spotting the comet with binoculars and amateur telescopes should be relatively simple. Leonard might even be visible to the naked eye, but the behavior and brightness of comets are challenging to predict.

"At present, Leonard exhibits a modest yet abundant dust tail," according to Sky & Telescope. "If its dust production rate escalates in the upcoming weeks as the comet approaches the Sun and becomes more active, two special circumstances - an orbital plane crossing and a high phase angle - may enhance its luminosity beyond forecasts."

Leonard's nearest encounter with Earth will occur on December 12, during which it will be 34 million km away. At perihelion, Leonard will be 0.6151 AU from the Sun, or 92 million km.

The object should appear as an extremely faint blurry star. The good news is that Arcturus - the most luminous star in the northern constellation of Boötes and the fourth-brightest star in the nocturnal sky - can serve as a point of reference. Again, do not assume that you will be able to spot Leonard with your naked eyes alone, as you will likely require some optical aid.

Stargazers in the Northern Hemisphere should currently search for Leonard high in the early morning sky while facing east. As Space.com reports, Monday December 6 will provide an exceptional opportunity to observe Leonard (depending on local weather conditions):

You will promptly notice the brilliant orange-yellow star, Arcturus in the constellation of Boötes the Herdsman. Now, with binoculars, survey that area of the sky approximately 5 degrees to the left of Arcturus, and you should come across Comet Leonard. The comet's dust tail, which began to extend noticeably during early November, should be pointing nearly vertically.

Leonard "will simply be about half the width of a clenched fist to the left" of Arcturus, Ed Krupp, an astronomer and the director of the Griffith Observatory in Los Angeles, informed NPR.

Later this month, from approximately December 14 to 16, the comet will be observable after sunset, appearing very low along the southwest horizon.

The comet will vanish from sight after Christmas, but only for viewers in the Northern Hemisphere. Observers in the Southern Hemisphere can catch a glimpse of Leonard starting in mid-December and extending into early January, as reported by EarthSky.

At speeds reaching 254,412 km per hour in relation to Earth, Leonard is regarded as an ultrafast comet. That being said, Leonard will still appear motionless in the sky due to the vast distances involved, but its velocity implies that its position in the sky will alter on a daily basis. EarthSky has provided some practical diagrams that you can use to monitor the comet’s position in the upcoming days and weeks.

Sky & Telescope states that it will take Leonard 35,000 years to reach its farthest distance from the Sun, which indicates that a complete year on Leonard endures for approximately 70,000 years. This serves as even more incentive to make the endeavor to observe this comet.