Last July, Comet C/2020 F3 (NEOWISE) dazzled skywatchers in France, easily spotted near the Big Dipper's claws. Could we witness a similar spectacle with Comet Leonard this year?
Comet Leonard, officially C/2021 A1, was discovered in January 2021 by astronomer Gregory J. Leonard at Mount Lemmon Observatory in Arizona's Santa Catalina Mountains. At discovery, it glowed faintly at magnitude 19—about 160,000 times dimmer than the faintest stars visible without aid. (Higher magnitude means lower brightness.)
Positioned roughly five astronomical units (AU) from the Sun—five times Earth's distance (149.6 million km)—it orbited near Jupiter. Here, solar heat triggers sublimation of methanol (CH3OH) and water ice into gas, forming the comet's initial faint tail.
Early orbital models show a highly elongated path, stretching beyond 3,500 AU (523 billion km) from the Sun. Yet, it approaches significantly: on December 12, it'll pass just 34.9 million km from Earth, and under 92 million km from the Sun on January 3, 2022.
Comets are notoriously unpredictable, but projections suggest a peak brightness of around magnitude 4. This could make it visible through binoculars or a small telescope—and possibly even to the unaided eye under dark skies. Post-perihelion, it fades quickly in twilight.
Optimism stems from its closed orbit, likely a prior solar visit around 70,000 years ago. Unlike fresh long-period comets prone to volatile outbursts (from CO2, nitrogen, CO ices vaporizing early), seasoned ones like this offer steadier displays without sudden fades.
