Venus and Jupiter’s Last Dance

And what a pair they make

Venus and Jupiter culminate their month-long serenade this week, pulling within two degrees of one another early evening Sunday and Monday. Look for them low in the southwest after sunset, around 4:45. Venus is the brighter of the two, but both are by far the brightest objects other than the moon, which emerges as a nascent crescent close to the horizon Sunday and just a few degrees above the planets Monday, so close, in fact, that your fist at arm’s length will blot out all three. After this week, Venus climbs higher while Jupiter disappears amid the glare of the horizon.

As the planets sink in the southwest, winter’s great hunter rises in the southeast, appearing higher in the sky as the nights grow darker and colder. While many of the constellations are dim abstractions at best, two brilliant first-magnitude stars, the line of three stars making up Orion’s belt and the hunter’s hourglass shape, make this one of the most familiar figures in the heavens.

Rigel, whose name in Arabic means leg of the giant, marks the hunter’s forward-planted foot. The seventh brightest star in the heavens, Rigel is a blue-white super-giant, nearly 20 times more massive than our sun.

Opposite Rigel and a contrast in color is the red-giant Betelgeuse, which marks Orion’s shoulder. Even though a whopping 600 light years away, Betelgeuse is 18th brightest star. It is so large that in our sun’s place it would consume the Earth and stretch halfway to Mars.

The three aligned stars of Orion’s belt are, from east to west, Anilam, Alnitak and Mintaka. They are sometimes called the string of pearls and also the Magi, for the three wise men who traveled west to Bethlehem.