Watch This Icy Comet Pass Earth for the First Time in Thousands of Years

Sharp-eyed skywatchers are getting ready to see a comet glide past Earth next month, in its first visit in an estimated 70,000 to 80,000 years.

The comet, called C/2021 A1 Leonard, was discovered at the start of this year on January 3 by Gregory J. Leonard, a senior researcher at the Department of Planetary Sciences at the University of Arizona. Leonard spotted it at the Mount Lemmon Observatory in the Santa Catalina Mountains, Arizona, reported.

Scientists are hoping that in December C/2021 A1 Leonard might be close enough and bright enough to be seen with the naked eye.

Speaking to astronomy magazine Sky at Night last week, comet chaser José J. Chambó said the comet's brightness had increased "dramatically" when he took two photos of it a couple of weeks apart last month.

The comet might be moving incredibly fast relative to Earth, but because it's covering such a huge distance, C/2021 A1 Leonard may be visible after sunset for several days.

According to Sky at Night, the comet may become visible to the naked eye between December 10 and December 16, peaking in brightness on December 13.

Meanwhile, the Virtual Telescope Project is due to host a live-stream of the comet on December 8. It's due to host the stream starting at 4 a.m. UTC (11 p.m. ET on December 7) on its webTV page here.

An orbit diagram of C/2021 A1 Leonard is available on TheSkyLive and shows how its path around the sun is highly elliptical—meaning instead of having a circular orbit like Earth does, it is shaped like an oval.

As such it will swing into the inner solar system, crossing the orbital path of Venus, before shooting off into space once again in a sling-shot effect enabled by the sun's immense gravity.

Leonard estimated its previous orbital period was 80,000 years, while the estimate of 70,000 was reported by Sky & Telescope magazine.

In a University of Arizona press release on December 13, Leonard said the comet would not be returning to the solar system again.

"This is the last time we are going to see the comet," Leonard said. "It's speeding along at escape velocity, 44 miles per second. After its slingshot around the sun, it will be ejected from our solar system, and it may stumble into another star system millions of years from now."

Position in the Night Sky

The comet's position in the sky will change daily. Charts showing its location are available to see on, which states it will start off being visible in Northern Hemisphere skies before becoming visible in the Southern Hemisphere later on.

Comets are giant balls of ice and rock traveling through space, producing long tails behind them whenever they pass near the sun.

Whenever Earth passes through one of these comet tails, the fragments burn up in our atmosphere which is what causes meteor showers.

Arguably the most famous comet is Comet 1P/Halley, also known as Halley's Comet. It can be observed from Earth about once every 75 years.

Meanwhile the next meteor shower will be the Geminids, which are due to peak on the night of December 13 to December 14, according to the American Meteor Society.

Correction 20/12/2021, 12:41 p.m. ET: This article has been corrected because it previously stated that Comet Leonard would return to the solar system.

Girl using telescope
A file photo of someone standing in the twilight pointing a telescope at the sky. m-gucci/Getty