A once-in-a-lifetime opportunity to view the brightest comet is approaching, and won't happen again for tens of thousands of years
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Comet Leonard
Credit: Dan Bartlett

A comet will fly in the sky around Christmas (and we're not talking about Santa's reindeer)!

It's time to keep an eye out for a giant ice ball called Comet Leonard that is soon to become increasingly visible from Earth throughout the month of December as it heads towards the sun.

Named after Astronomer Greg Leonard who discovered it in early January of this year, the comet is expected to sweep closest to the Earth on Dec. 12, becoming viewable for space spectators watching from below. This comet flies in the morning sky, but is visible in the evening – similar to the Neowise comet in July.

Leonard is considered a "much-anticipated comet" that is "likely to be 2021's best comet – and its brightest comet by year's end," according to EarthSky.org. As it travels closer to the sun and Earth, discovery images suggest that we might see a long, dust tail with a sparkling trail left behind.

Comet Leonard
Credit: Patrick Prokop

The comet is directed sunward as it draws closer to its perihelion (the closest point to the sun) on Jan. 3, the state in which Leonard will be at its brightest. When it reaches its closest point to the Earth, it still won't be particularly near as it will pass more than 21 million miles away.

Six days later, though, Leonard will become exceptionally close to Venus passing just 2.6 million miles away (well, exceptionally close in cosmic standards). By the time it flies by the sun, it will be at a distance of about 56 million miles in proximity.

UPDATE (12/17): Comet Leonard is approaching Venus sooner than expected, and will be viewable to skywatchers on Dec. 17 at approximately 9:08 p.m. EST. Venus is often referred to as the "evening star," and can be seen low above the horizon shortly after the sun sets, according to Space.com.

Want to spot Comet Leonard for yourself? Typically, this comet is considered too faint to see without binoculars, but as it moves closer to its perihelion, skywatchers have a chance to observe it with their naked eye in extremely dark skies.

Comet Leonard
Credit: Eddie Irizarry/Stellarium

"During the first two weeks of December, Comet Leonard will be accessible to early risers, visible a couple of hours before sunrise, low in the east-northeast sky," reported Space.com. "It will track through the constellations Coma Berenices, Boötes and Serpens Caput."

But eyeing Leonard is not guaranteed, as comets are often unpredictable. You might've heard the term "magnitude" used when describing a star's apparent brightness but nowadays, the magnitude system includes the moon, planets, asteroids and comets within the solar system (and star clusters and galaxies that reside outside the solar system), according to EarthSky.org.

As Comet Leonard nears the sun towards January, it might reach 4th magnitude; but since comets are diffuse bodies, it won't appear as bright compared to a 4th-magnitude star. The good news is, the moon will be absent during the twilight hours making the sky extra dark.

comet
Credit: Getty

"Orbital calculations revealed that the object had spent the last 35,000 years wending its way sunward after reaching aphelion at the chilling distance of around 3,500 AU" (3,500 times the distance between our Earth and sun), reported Skyandtelescope.com.

That means, spotting this comet is a once-in-a-lifetime experience since it takes tens of thousands of years to complete an orbit around the sun. (So, grab a pair of binoculars or a telescope and look up!)

What are you looking for exactly? Don't expect to view Leonard like you would a shooting star. Although this celestial visitor is an especially speedy comet, traveling at 158,084 miles per hour relative to Earth, it will appear very slow due to the large distance involved.

Comet Leonard was discovered on Jan. 3, 2021 "as a faint smudge in January 2021 when it was out past Mars," according to NASA. Pictures were captured with it sporting a green-tinged coma and an extended dust tail, "composed from 62 images taken through a moderate-sized telescope -- one set of exposures tracking the comet, while another set tracking the background stars," continued the space agency.