Gemini is one of the easiest constellations to see, as it does resemble a pair of twins. Connect the stars in the western sky this month with imaginary lines and two figures magically appear. You won't need a telescope to see Pollux and Castor, the brilliant stars at the twins' heads and for whom they are named. You should also be able to see ruddy Mars, which appears near Castor's foot at mid-month and traverses the torso of each twin as the month progresses.
If you do aim your telescope at Mars, above the two visible stars marking Castor's foot, you'll see dozens of stars in a cluster called Messier 35 or simply M35, named in the 18th century by Charles Messier. In a very dark sky, you may even be able to see the cluster with unaided eyes. With a telescope, you may also see smaller and fainter NGC 2158, another cluster sharing the same eyepiece field of view as Messier 35. Though these two clusters are nearly the same size, Messier 35 is closer, about 2800 light years distant from Earth, and appears larger than NGC 2158, which is 10 times older and six times further away.
Meanwhile, Saturn has been hovering near another star cluster, Messier 44, the Beehive cluster for several months. Look for Saturn higher in the sky, above the head of the other Gemini twin, Pollux. Watch Saturn and Mars over the next month. They will move closer together near the Beehive cluster by late May.
Editors Note: M35 is actually northeast of the other cluster. The view in the image of the two clusters is inverted to match most telescope views.
Last Updated: 24 February 2011