If you see a greenish blob glowing in the night sky, it’s no UFO — it’s a comet known as 46P/Wirtanen.
The brightest comet of the year is on display this weekend, with its closest approach on Sunday.
The comet, made of ice and rock, will be 7,199,427 miles from Earth. That may seem far, but it is actually among the 10 closest comet approaches since 1950.
“This will be the closest comet Wirtanen has come to Earth for centuries and the closest it will come to earth for centuries,” said Paul Chodas, the manager of the Center for Near-Earth Object Studies at NASA’s Jet Propulsion Laboratory, in a statement.
However, those expecting a spectacular show like the one put on by Halley’s Comet will be disappointed.
Wirtanen, which is sometimes called the “Christmas comet,” according to the New York Times, is only about a tenth the size of Halley’s Comet and likely will not grow the classic tail large comets are known for. Instead, it will appear as a nebulous ball of light in the sky.
To spot Wirtanen, look several fist-lengths to the right of Orion’s Belt — the well-known constellation that features three stars — and left of the Pleiades. The comet will be visible to the naked eye under dark skies; use binoculars or a telescope to get a better view.
The 46P/Wirtanencomet was named for astronomer Carl Wirtanen, who discovered it in 1948. The comet orbits the sun about every 5.4 years.