A year ago, it was still an incredibly dim and obscure chunk of rock traveling out near the Jupiter.
It's being billed as the best comet of the year because it's reached our neighborhood of the solar system.
You can see it here.
Ed Krupp, an astronomer and the director of the Griffith Observatory in Los Angeles, tells me that the comet is in the early morning sky and that means getting up very early.
The best time to be in North America is Monday morning, when the comet will be low on the horizon. The constellation Botes has a star. You can find it by following the curve of the Big Dipper past the end of the handle. Arcturus will be the next bright star. A good memory aid is to remember that you "arc to Arcturus" from the Dipper handle.
Krupp says the comet will be about half the width of a clenched fist. "You might see it with your eyes, but you're going to need a telescope or binoculars to see it."
It can be difficult to determine how bright a comet will be, and often a matter of intense speculation among amateur and professional astronomer alike. Leonard is the same.
Peter Veres, an astronomer at the Minor Planet Center at the Harvard-Smithsonian Center for Astrophysics, says that Leonard might be a disappointment to people who saw Neowise in the summer of 2020.
If you compare it to the comet Neowise, I wouldn't say it will be spectacular.
Leonard might be visible with the naked eye, but he needs to be far from the city.
Krupp says that if you miss it in the morning, you will get another chance in the evening.
He says the best time to be in the evening is December 17th.
Look for the planet Venus to the southwest. After the sun and moon, the planet is the most visible object in the sky. The comet is going to be between Venus and the horizon.
Things get more challenging for Northern Hemisphere observers after that. They need to book a flight to the Southern Hemisphere next month. Australia, anyone?
You'll be out of luck after Leonard leaves the southern skies. Neanderthal and Homo sapiens were the last people on Earth to have seen a comet.
We'll be the last humans to see it. The comet will be kicked out of the solar system after it flies by Earth.
