Remember Comet NEOWISE in 2020? That was quite a sight in the night sky, surely the “comet of the decade.

But there is more to come. In December, there’s no doubt what’s going to get the title of “comet of the year” for 2021.

First discovered at Arizona’s Mount Lemmon Observatory on January 3, 2021 by Greg Leonard, a senior research specialist (hence the name “Comet Leonard”), C/2021 A1 (Leonard) is now on the edge of being visible to binocular and even the naked eye.

Comet Leonard will make its closest approach to the Sun-on January 3, 2022, but before that, it will get closest to the Earth and, hence, be the brightest, on December 12, 2021.

It’s going to appear in the eastern predawn sky and the best dates for viewing are Dec. 1-12, 2021.

How bright will Comet Leonard be?

Not known for sure, but it’s predicted to reach around magnitude 4 or brighter in December, which means it just might be visible to the naked eye.

Astronomers recommend using binoculars, though about 42 or 50×10 will be perfect for the best chance of glimpsing this icy return visitor to our Solar System. A small telescope ought to provide a fine view, too. Astronomers have theorized the comet last visited the earth 35,000 years ago. No binoculars then.

How to see Comet Leonard

It’s recommended you find as dark as sky as possible and look to the eastern night sky just before dawn. The closer to dawn you look, the higher it will be, but the brighter the sky will be. So it’s balancing act that also, obviously, requires clear skies.

Finding Comet Leonard in early December

Look east in early December and you’ll see Arcturus, the brightest star in the constellation of Bootes. Comet Leonard will be above it.

Key dates to look for Comet Leonard are:

  • December 6, 2021: Comet Leonard will be less than 5º from Arcturus.
  • Sunday, Dec. 12: Comet Leonard will switch to being a morning object.
  • Friday, Dec, 17: Comet Leonard will be close to Venus.

Comet Leonard ‘grazes’ Venus

Astronomers recently published a paper that describes how close Comet Leonard will get to Venus—and it’s going to be really close!

On December 18, 2021, scientists predict that Comet Leonard will pass just 2.6 million miles/4.3 million kilometers from the second planet from the Sun. It will then graze Venus with its dust trail less than two days later. If anybody lived on Venus they would be getting a fantastic view!