Beautiful Photos Show Comet Leonard Passing Earth Before It Vanishes Forever

The brightest comet of the year is continuing to pass over Earth this week, with astrophotographers from around the globe taking the once-in-a-lifetime opportunity to capture the shiny ice ball.

Leonard, also known as C/2021 A1, was discovered in January 2021 by Gregory J. Leonard, an astronomer and research specialist at the University of Arizona.

In the months that followed, researchers noted that Leonard was on a trajectory that would take it relatively near to the Earth on its journey towards the sun, and that people may be able to see it with the naked eye by December.

As it happens, comet Leonard is not quite visible to the eye alone, according to EarthSky—though some keen observers might be able to catch it with clear, dark skies. It is a good comet to spot with telescopes and 10x50 binoculars, though.

The below photos of the comet were captured by photographers based in the U.K. and in Texas, followed by a timelapse from Christopher Becke in Virginia.

From North America and similar latitudes, people should be able to spot Leonard by facing east about 45 minutes before sunrise somewhere below the Big Dipper constellation and the star Arcturus, according to an Eddie Irizarry illustration posted on EarthSky.

That's up to December 12. After that, the best time to spot the comet will be in the early evening after sunset, when the comet might be visible in the southwest as it moves past Venus and Mercury and onwards towards Saturn and Jupiter, according to the Astronomy magazine website.

Comet Leonard has an estimated orbital period of between 70,000 and 80,000 years, meaning it has taken that long to pass around the sun. This is because its orbit is highly eccentric, or oval-shaped rather than circular.

Leonard said we will never see the comet again once it completes its close pass to the sun.

He said in a University of Arizona press release on December 13: "This is the last time we are going to see the comet. 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."

Observers have noticed that while Comet Leonard appears to have gotten brighter than usual because it's now relatively near to Earth, in reality it's actually fading.

Quanzhi Ye, an astronomer at the University of Maryland, told Space.com that there are a number of guesses as to why the comet is fading, but the most obvious one is that it is splitting up or is likely to do so soon.

Comets are balls of ice, gas and rock that orbit the sun. As they got closer to our star, they heat up and spew material out into space behind them, leaving their trademark tails that can stretch for millions of miles.

Eventually, a comet will evaporate more or less completely. It's still unclear if this is what is happening to Comet Leonard at the moment.

According to NASA, the number of known comets is 3,743, but it's thought there are billions orbiting the sun in total.

Correction 20/12/2021, 12:49 p.m. ET: This article has been updated to state that Comet Leonard will not return to the solar system and to correct the headline.

Update 20/12/2021, 12:49 p.m. ET: Estimates of Comet Leonard's orbital period have been updated to between 70,000 and 80,000 years.