The so-called ‘Christmas star’ will light up the sky starting December 21, 2020, when planets Jupiter and Saturn align.
The rare phenomenon, termed in science as a ‘Great Conjunction’, only happens every 800 years. The two planets align every 20 years, but astronomers say it takes hundreds of years for conjunction this close to happen.
The alignment gives an impression of a double plane when being viewed from Earth.
“The last time they were this close was about 400 years ago in 1623,” says David Weigel, director of the INTUITIVE Planetarium at the U.S. Space & Rocket Center in Huntsville, Ala. That’s the time of early astronomers like Gallileo and Johannes Kepler, Weigel said in a report on Alabama news.
“Kepler was the first person who really understood how orbital mechanics worked and these objects traced elliptical paths through space. Once he was able to figure out the equations that governed this, he was able to trace time back a little bit and try to understand what things were like in the past,” he added.
Enthusiasts can catch the alignment on the sunset of December 21.
Observers can use binoculars or telescopes to appreciate the beauty of this phenomenon more, according to experts.
