Asking Directions

One of the greatest thrills of stargazing is recognizing old friends in the sky. Greater still is when these friends lead you to unexpected treasures. That is something that can occur on any clear night. Like tonight.

All of us have marveled at the beauty of the Big Dipper. Most can also recognize the stars of Orion, with his bright belt of three gleaming stars. These are the guides to the winter nighttime sky.

Just as the end stars of the Big Dipper are pointers to the north star, Polaris, the inner stars of the bowl are pointers, too: to mighty Leo the lion. That' s the way star-finding works: you start with a few constellations that you' ve known since you were a child, and use the stars of that constellation to find others. The shoulders of Orion point to the Gemini twins, Castor and Pollux. Four friends in the sky tonight: the Big Dipper, Orion, Leo, and Gemini. Where will they lead us?

Well, halfway between the blazing heart of Leo (Regulus,) and the Gemini twins is the beautiful Beehive star cluster. It's easy to find because it's so big, three times as large as the full moon! You just have to pan your binoculars from Regulus to Pollux. This cluster is so tight that it really does look like a swarm of bees when seen through binoculars. An open star cluster such as the Beehive is a group of stars numbering in the hundreds. They were born together about 400 million years ago. Now they are now caught in one another's gravitational grip and circle each other as they move as a group through space. This type of cluster is being born right now in the Orion nebula. Look at his sword and you'll see the nursery -- a giant cloud of interstellar gas.

(1/20/99)