The International Dark Sky Discovery Center of Fountain Hills is letting people know that this evening there will be a once-in-a-lifetime opportunity to observe a celestial phenomenon.

The planetary conjunction of Jupiter and Saturn will be observable in the sky shortly after sunset, and no telescope or binoculars are needed (unless the observer wants to see there is a separation of the planets).

The alignment can be seen fairly high in the sky over Fountain Hills somewhat south and west of straight up. It will appear as the sky gets dark after sunset. They will set below the horizon within an hour or two.

While the planets remain 400 million miles apart, they will be in perfect alignment when seen from Earth to make them appear as a single light. While the two large planets do a similar dance on a regular basis the last time they were this close together was 1226, around the time Galileo was developing the telescope.

Some believe this planetary alignment accounts for the description of the Christmas Star that led the Wise Men to Bethlehem.