Meet Leonard, the Brightest Comet of the Year

The celestial object will reach peak visibility in the northern hemisphere on December 12 and should be visible until the end of the month

Photo of a comet whizzing through space. The comet is a bright blue orb with a tail behind it; stars fill up the background
As comets near the sun, they begin to form a head and tail. NASA/Bill Ingalls

Leonard's comet has been barreling through the galaxy en route to the sun for around 35,000 years, and Earthlings hoping to catch a glimpse should start keeping an eye on the sky, Margo Milanowski reports for Popular Science.

Leonard will be visible for a couple of weeks this month as it soars past Earth, but it will be closest—just 21 million miles away—on December 12. This week, folks living in the northern hemisphere should face eastward and look high in the sky to see Leonard, which is expected to be the brightest comet of the year, George Dvorsky reports for Gizmodo.

According to NASA, comets are "frozen leftovers" of dust, rock and ice from when the solar system formed. As they near the sun and its heat, comets form a bright, glowing head with a tail of dust and gas that can stretch for millions of miles. Leonard will look like a round, hazy speck in the sky with its tail pointing straight up, Joe Rao reports for

"The comet is in the early morning sky right at the moment, and that means getting up very early, probably around 5 A.M. or so and looking more or less to the northeast," astronomer Ed Krupp, the director of the Griffith Observatory in Los Angeles, tells Scott Neuman for NPR.

Leonard will be hidden among the constellation of Boötes the Herdsman, near the orangey star Arcturus. Throughout the month, Leonard will brighten and become easier to spot, but then it will slowly sink in the eastern sky, reports.

Later in the month, the comet will start appearing a little after sunset between the southwest horizon and Venus, NPR reports.

"The optimum time [in the evening] probably is from the Dec. 17 on," Peter Veres, an astronomer at the Minor Planet Center at the Harvard-Smithsonian Center for Astrophysics, tells NPR. But Leonard may be hard to spot, so "you will need to be in a dark environment, far from the city."

But in early January, Leonard will disappear from view for residents of the northern hemisphere. This year will likely be the last time humans ever catch a glimpse this comet, Popular Science reports.

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