The great conjunction of Jupiter and Saturn, the first of its kind in 400 years

In a rare spectacle, Jupiter and Saturn will have one of their closest alignments on Monday — so close that a pinkie finger at arm’s length will easily cover both planets in the sky.

The great conjunction of the planets, appearing on the evening of December 21, is mistakenly called the Christmas Star.

This event happens about once every 20 years but the closeness of the two planets makes this a very rare conjunction.

Why? Because it’s been nearly 400 years since the planets passed this close…