Jupiter, left, and Saturn appear about one-tenth of a degree apart. Here they are seen behind Christmas lights in Las Vegas.

LAS VEGAS, NEVADA – DECEMBER 21: Jupiter (L) and Saturn appear about one-tenth of a degree apart during an astronomical event known as a Great Conjunction behind Christmas lights in the front yard of a house on December 21, 2020 in Las Vegas, Nevada. The planets, which remain about 450 million miles apart in space, have not appeared this close together from Earth’s vantage point since 1623, and it’s been nearly 800 years since the alignment occurred at night. The conjunction, which occurs on the night of the winter solstice by coincidence, has become known popularly as the “Christmas Star.” The gas giants will not appear this close together again until 2080. (Photo by Ethan Miller/Getty Images)