Astronomer explains the “Christmas Star” as Jupiter, Saturn converge in the night sky

Astronomer explains the “Christmas Star” as Jupiter, Saturn converge in the night sky

It's being called a once-in-a-lifetime event as Jupiter and Saturn merge in the night sky Monday, appearing closer than they have in 400 years. Astronomer Dr. Lucianne Walkowicz of the Adler Planetarium explains the phenomenon some are calling the “Christmas Star.”