Watch for occultations tonight

We have all heard the little phrase that says if March comes in like a lion, it will go out like a lamb. Many of you long- time readers know I have discussed this before, but it never hurts to go over it again.

The basis of that phrase has its roots in astronomy. Just as Pegasus is an indicator of autumn, and Orion of winter, so Leo is an indicator that spring is at hand and his stars have been peeking over the eastern horizon these past few weeks.

Leo is one of the few constellations that actually looks like what it is supposed to be, a lion. Start by looking east about an hour after local sunset. There just above the horizon is what looks like a giant backwards question mark.

That is the head and mane of the beast with the bright star Regulus -- Latin for "Little King -- serving as the dot below the symbol.

The rest of his body extends to the left ending in a second magnitude star, Denebola, which means literally "Tail of the Lion."

Okay, so much for the lion, how about the lamb? Well, there is no actual lamb among the stars, but there is, however, a ram, Aeries, the Ram to be exact. He can be found on the opposite side of the sky from Leo at sunset.

Aeries is a very difficult constellation to find. It only has three major stars at second and third magnitude. That means you will need a very dark-sky place to observe them. First find the "V" shape of Taurus, the Bull, the let your eyes drift down and to the right to find those three stars in an almost straight line rising up from the horizon.

Now, what has this to do with the coming in and going out thing? OK, on the first of March Aeries is very high above the 0horizon and Leo very low. By the end of the month their positions have reversed and Leo is high and Aeries is low.

Now that we have Leo pointing the way, what about spring itself? Spring officially occurs at 10:57 am on Thursday, March 20, when the Sun crosses the celestial equator heading north in an event called the "Vernal Equinox."

If you haven't noticed by now, you should soon. The days are growing longer and the nights are growing shorter.

Now, tonight, Wednesday, March 12, will be a nice occultation when an almost-full moon occults -- or covers -- the star 60 Cancri in Cancer the Crab. You will have no problem finding it because it is very, very close on the moon's left as you are looking at it.

However, before the occultation, there are some other celestial fireworks. Before sunset the moon is covering up the nice open star cluster, Messier object, M67, a nice open star cluster. If you look at the moon with binoculars or a telescope at about 7:40 pm MDT, the cluster will be just to the right of the moon. Look for a nice sprinkling of stars.

The real fireworks start just after 10 pm MDT. At about 10:10 pm MDT the star 60 Cancri will wink out as the dark, leading edge of the moon covers it. It you keep watching for another 40 minutes or so the star will pop out on the other side of the moon.

SKYWATCH: Full moon, Sunday, March 16. The moon Spica, and Mars will make a nice trio in the early morning hours of Tuesday, March 18 and 19, look to the east.

NEXT WEEK: More astronomical blathering.