C/2021 A1 (Leonard) was a long period comet [5] that was discovered by G. J. Leonard at the Mount Lemmon Observatory on 3 January 2021 (a year before perihelion) when the comet was 5 AU (750 million km) from the Sun. [1] It had a retrograde orbit. The nucleus was about 1.2 km (0.75 mi) across.

Comet C/2021 A1 (Leonard) was discovered as a faint smudge in January 2021 when it was out past Mars -- but its orbit will take the giant shedding ice-ball into the inner Solar System, passing near both Earth and Venus in December before it swoops around the Sun in early January 2022.

2021年12月22日 · Comet Leonard — the brightest and most anticipated comet of the year — was discovered by Gregory Leonard, a senior research specialist at the University of Arizona's Lunar and Planetary...

Keep an eye on the skies this month for a rare comet that's fading fast. Comet C/2021 A1 — a.k.a. Comet Leonard — will be visible for a little bit longer through mid-January. It flew past Earth at a distance of about 35 million kilometers (22 million miles) on Dec. 12, and made its closest approach to the Sun on Jan. 3.

2021年11月22日 · Comet C/2021 A1 (Leonard) was discovered as a faint smudge in January 2021 when it was out past Mars — but its orbit will take the giant shedding ice-ball into the inner Solar System, passing near both Earth and Venus in December before it swoops around the Sun in early January 2022.

2022年1月5日 · Comet Leonard is falling out of view, but not without putting on one last show. Discovered just a year ago, the comet, formally known as Comet C/2021 A1, made its closest …

The featured image of Comet C/2021 A1 (Leonard) was taken a week ago from California, USA. The deep exposure shows in great detail the comet's green gas coma and developing dust tail. The comet -- across our inner Solar System and only light-minutes away -- was captured passing nearly in front of globular star cluster M3.

2021年12月13日 · Now is the best time to get a glimpse of Comet C/2021 A1, better known as Comet Leonard. It's named for its discoverer, Gregory Leonard, a senior research specialist at the University of Arizona Lunar and Planetary Laboratory.

2021年12月21日 · When Comet Leonard, a mass of space dust, rock and ice about a half-mile (1 kilometer) wide, makes its closest pass of the Sun on Jan. 3, 2022, it will be a journey 40,000 …

2021年12月25日 · Comet Leonard (C/2021 A1), which appeared to stall out around magnitude 5 in early December, has become a surprise performer. Since transitioning to the evening sky, it’s undergone three successive bright outbursts — on December 15th, 20th, and 23rd — that catapulted it to naked-eye visibility at 3rd magnitude.