Planetary Society logo
  • “Exploration is in our nature.” - Carl Sagan

Kate Howells • Jan 10, 2022

How to see Comet Leonard

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. The comet is now on course to exit the solar system.

It is now nearly too close to the horizon to see it in the evening from the Northern Hemisphere, but Southern Hemisphere observers might still be able to catch a glimpse of the comet before it vanishes into the cosmos.

Comet C/2021 A1 "Leonard"
Comet C/2021 A1 "Leonard" Comet Leonard photographed through a telescope on Dec. 3, 2021.Image: Adam Block /Steward Observatory/University of Arizona

Visibility will be best through binoculars or a telescope, and in dark sky areas. Find more night sky viewing tips here.

Comet Leonard in the evening sky
Comet Leonard in the evening sky A view of the evening southwestern sky as it will appear in the Northern Hemisphere around Jan. 10. Image generated using Stellarium.
Comet Leonard in the evening sky, Southern Hemisphere
Comet Leonard in the evening sky, Southern Hemisphere A view of the evening western sky as it will appear in the Southern Hemisphere around Jan. 10. Image generated using Stellarium.

Comet Leonard also flew by Venus on Dec. 18, coming closer to the planet than any previously documented comet, within 4 million kilometers (2.5 million miles).

Greg Leonard, an astronomer with the University of Arizona’s Catalina Sky Survey, spotted C/2021 A1 in January 2021. This is the thirteenth comet Leonard has discovered.

Take action for space exploration!

Give today to have your gift matched up to $75,000.

Donate