Photos: Cold Moon 2021 brightens the night sky The cold moon rises at sunset behind Monte Camicia mountain in Gran Sasso National Park in Italy on December 18, 2021. (Lorenzo Di Cola/NurPhoto via Getty Images)
Photos: Cold Moon 2021 brightens the night sky The December 2021 full moon, called the "Cold Moon," is seen over Buenos Aires on December 19, 2021. (EMILIANO LASALVIA/AFP via Getty Images)
Photos: Cold Moon 2021 brightens the night sky The full moon, also known as the "Cold Moon," is shown behind people standing on the Edge, the outdoor observation deck in Manhattan, New York City, on December 19, 2021. (Tayfun Coskun/Anadolu Agency via Getty Images)
Photos: Cold Moon 2021 brightens the night sky The December full moon, also known as the "Cold Moon," rises behind the Brooklyn Bridge in New York City, as seen from Jersey City of New Jersey, on December 19, 2021. (Tayfun Coskun/Anadolu Agency via Getty Images)
Photos: Cold Moon 2021 brightens the night sky A full moon glows through tree branches and behind clouds Sunday, Dec. 19, 2021, in Hokkaido, Japan. (AP Photo/Kiichiro Sato)
Photos: Cold Moon 2021 brightens the night sky The cold moon rises at sunset behind Monte Camicia mountain in Gran Sasso National Park in Italy on December 19, 2021. (Lorenzo Di Cola/NurPhoto via Getty Images)
Photos: Cold Moon 2021 brightens the night sky The moon rises above the Graca neighborhood as night falls in Lisbon on Saturday, Dec. 18, 2021. (AP Photo/Armando Franca)
Photos: Cold Moon 2021 brightens the night sky The moon rises at Centenario Stadium in Montevideo, Uruguay, on Friday, Dec. 17, 2021. (AP Photo/Matilde Campodonico)
Photos: Cold Moon 2021 brightens the night sky The moon rises above the Dolomite mountain peaks, in Val Gardena, northern Italy, on Saturday, Dec. 18, 2021. (AP Photo/Gabriele Facciotti)
Photos: Cold Moon 2021 brightens the night sky The full moon sets behind trees of the Lebanese presidential palace in Baabda, east of Beirut, Lebanon, on Sunday, Dec. 19, 2021. (AP Photo/Hassan Ammar)