Christmas comet 2021: How to see once-in-a-lifetime comet soar through the sky


Santa Claus and his eight tiny reindeer won’t be the only shiny thing streaking through the Christmas week sky.

Comet Leonard, or C/2021, the brightest comet of 2021, is visible this week. The comet made its closest approach to Earth on Dec. 12 when it was about 21 million miles away from Earth or roughly 88 times the distance from Earth to the moon.

The comet is named for its discover Gregory Leonard, a senior research specialist at the University of Arizona’s Lunar and Planetary Laboratory. Leonard said the comet will appear very low above the horizon just before sunset but might be difficult to see.

“It will skim across the west-southwestern horizon between now up until around Christmastime. The fact that it’s so close to the horizon makes this comet a bit challenging to observe,” Leonard said.

It’s still worth giving it a try to see the once-in-a-lifetime appearance, Leonard said, especially since the comet may create an effect known as “scattering.” Scattering occurs when the comet comes closer to the sun and its tail and “coma” – a cloud of dust and gas – scatters sunlight behind it, potentially dramatically enhancing

“I feel there is going to be something to be seen even for the casual observer,” Leonard said. “Find yourself a dark sky with a good view of the horizon, bring binoculars and I think you may be rewarded.”

The comet can now be seen in the evening sky and is best viewed around an hour or so after sunset.

People who want to see the comet should give it a try since it won’t be making a repeat appearance. Leonard said the comet made its first appearance about 80,000 years ago and won’t be back anytime soon.

“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,” he said.