If you enjoy stargazing, it’s time to get ready for a once-in-a-lifetime celestial event.
After December 14, you’ll be able to see the newly discovered Comet Leonard for a while just after sunset as it nears the sun. Then, on January 3, it’ll pass the sun and move out into space — never to be seen from Earth again.
About the “size of a small town,” a comet essentially is an ice ball made of frozen gasses with embedded rock and dust particles, NASA explains.
As a comet nears the sun, it warms up and its ice begins to change from a solid to gas. This produces what’s known as a “coma,” which is the fuzzy-shaped cloud surrounding the ball of ice. The coma, by the way, can be thousands of miles in diameter.
What’s even more impressive is that radiation pressure — or solar wind — then “blows” the expanding coma out to form the tail that comets are known for, Space.com explains.
Comet Leonard, cataloged C/2021 A1 by NASA, was discovered by — and named in honor of — astronomer Gregory J. Leonard earlier this year, on January 3, 2021. Leonard is a senior research specialist for the Lunar and Planetary Laboratory’s Catalina Sky Survey, located at the Mount Lemmon Infrared Observatory, just outside Tucson, Arizona.
The comet, which likely spent the last 35,000 years traveling toward the sun, has what’s called a “hyperbolic orbit.” That means Comet Leonard will move through the inner solar system once, and then continue moving further out into space after it passes the sun.
The Comet’s Approach
Comet Leonard gets brighter as it nears the sun, making it easier to see. The comet will be at its closest to earth on December 12, which is just a couple of weeks before it reaches its closest distance from the Sun. Interestingly, when Leonard passes earth, it will still be 21 million miles away.
“In the first weeks of December, Comet Leonard can be found in the east before sunrise, passing between Arcturus and the handle of the Big Dipper,” NASA explains. “It approaches the horizon right around the time of its closest approach to earth, meaning it’ll likely be brighter but more challenging to observe. It then switches over to being an evening object after around December 14, for just a little while after the Sun sets — as it begins its long haul outward from the Sun again, progressively fading in brightness.”
How To See Leonard
Comets, NASA explains, are “notoriously difficult to predict in terms of brightness and visibility.” Comet Leonard is predicted to peak at a brightness that will probably require binoculars to spot it.
To see Comet Leonard, you’ll need to look just above the southwest horizon about an hour after sunset. Venus will also be visible then, and Leonard will be slightly below the planet.
You can find tips for locating Comet Leonard in the night sky here.
To increase your chances of seeing Comet Leonard, you’ll want a viewing area that is really dark. You can find a map of dark places for optimal stargazing here.
It’s important to note that if you do plan to track the comet’s progress using a telescope, it will take some patience. It’s true that Comet Leonard will be traveling at approximately 158,076 miles per hour, or 44 miles per second. However, due to the great distances of space, the comet will appear to be moving through the sky slowly, EarthSky explains.
If you are using a telescope, you’ll need to fix Comet Leonard’s position in relation to background stars, and then look away. Then, in 5 to 10 minutes, look through the telescope again. You should be able to see that the comet has moved across the sky, EarthSky explains.
If it’s going to be too cold for your comfort outside, or if the sky will be cloudy in your location, there’s another option for watching Comet Leonard. The Virtual Telescope Project will be sharing a Livestream of Comet Leonard passing earth from its observatory in Rome.
You can access the Virtual Telescope here.
While you’re thinking about it, be sure to check out the rest of our stargazing coverage, including: