Night_skies_feb_23

Jeff Green | Feb 23, 2006

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TheNightSkies ofMarch, 2006:Mars marches and an eclipse happens!

by Leo Enright

In this area, at the beginning of March the sun sets a few minutes before 6 p.m. EST, and by the end of the month it is at about 6:30 p.m. During March, the end of evening twilight moves from about 7:30 p.m. to about 8:10 p.m.

The bright and familiar stars of the winter constellations, have moved into the southwestern part of the sky and they set about midnight. They include Orion the Great Hunter, with his distinctive “3-starred belt” and four brilliant stars to mark his shoulders and knees, and following him his Great Dogs, Canis Major and Canis Minor, whose shining eyes are marked by two of the sky’s brightest stars, Sirius and Procyon. Well above Orion’s head we can see the outline of the Heavenly Twins Castor and Pollux standing side by side. Moving up into the eastern sky during twilight we may well notice the first of the very large constellations of the spring sky Leo the Lion. Its starry outline resembles a “backwards question mark” indicating the head and front paws of the giant cat, and a large triangle of stars marks its hindquarters. At the foot of the “backwards question mark” is the star Regulus, known as the “Kingly Star” to our ancient ancestors, the brightest object in that part of the sky. The old saying about March - “In like a lion; out like a lamb” is actually astronomical: As Leo enters the eastern sky, Aries exits the western sky.

Among the bright planets, three may be seen this month in the evening sky and one in the morning sky, and it will be possible to see one planet, Mercury, in both the evening and morning sky. During the first few days of March, those who have a good view of their western horizon about 45 minutes after sunset may get a glimpse of this fleeting planet. After the first week of the month there is no chance of seeing Mercury until after its orbit carries it “to the other side of the sun” and it appears very low in the eastern morning sky during the last week of the month. Once again a good view of the eastern horizon is needed for a brief glimpse of Mercury beginning about 40 minutes before sunrise.

During the later evening, Mars, Saturn and Jupiter may be seen throughout March. Reddish Mars is on the run this month! Its orbital movement IS ACTUALLY VERY easy to detect this month. Remember that in early February this planet appeared near the bright stars of Aries, which are now setting on the western horizon in the evening twilight. Then Mars moved to the left and passed the famous Pleiades star cluster (which happened in mid-February) and this month it continues to move to the left (or eastward) in the sky until it will have passed the bright star Aldebaran (in the head of Taurus, the Bull). By the end of March it will be mid-way between the two stars that mark the tips of the Bull’s horns. Of all the superior planets, Mars thus is the one whose orbital motion around the sun is the easiest to see over the course of a single month. I suggest using a sketch pad to record its movement among the background stars. Saturn is very high up in the east during twilight, and as was the case last month, is in retrograde motion as the Earth passes it “on the inside” making Saturn appear to temporarily move backwards. During March it will appear to move from left to right by about one degree (the width of a finger held at arm’s length). As last month, Saturn appears slightly to the right of the star cluster called The Beehive Cluster in the constellation Cancer. Saturn appears almost, but not exactly, mid-way between the star Regulus in the eastern sky and the twin stars Castor and Pollux which are near the zenith (the point directly overhead) during mid-twilight. While the forward motion of Mars will be very easy to detect, the retrograde motion of Saturn may be detected this month, but only by those who observe its background stars very carefully. Jupiter rises in the southeast shortly before midnight in early March and at about 9 p.m. in late March. It appears among the stars of the constellation Libra and its brightness dominates the southern sky for the remainder of the night. Brilliant Venus dominates the southeastern sky during the hour and a half before sunrise. Those who observe it with binoculars may be able to see a crescent phase like that of a small moon. Its brilliance is now so great that it can be seen even after sunrise by those who follow its position in the sky, and look in exactly the right place.

A few lunar conjunctions can provide wonderfully memorable views of the celestial luminaries close to each other. In the southwestern evening sky on March 5, the First Quarter Moon will appear between the planet Mars and the Pleiades. On the evening of March 9 the gibbous moon will appear between the stars Castor and Pollux and the planet Saturn. In the late evening on the 18th, the waning gibbous moon will appear to the right of Jupiter. About 40 minutes before sunrise on the mornings of March 25 and 26, the slim Crescent Moon will appear fairly close to brilliant Venus in the eastern sky, and for those who have an extremely good view of that horizon on the 27th, the “super-thin” lunar crescent will be close to Mercury about 30 minutes before sunrise. Try to catch as many as possible of these memorable sights!

With the eclipse season upon us once again (as happens twice each year), we have a lunar eclipse at Full Moon and a solar eclipse at New Moon. From our location, we will be able to see PART of one of these events, if the weather cooperates. At moonrise on Tuesday, March 14, a Penumbral Lunar Eclipse will already be in progress, and so we will get to see about the last half of it. (In a Penumbral Lunar Eclipse, the moon enters, not the earth’s main shadow, called ‘the umbra’, but only the “partial shadow’ which is called ‘the penumbra’. In this case, the darkening on the moon’s surface is subtle and not well defined, as with a Total or Partial Lunar Eclipse.) Locally that evening, Moonrise occurs at 6:04 p.m., though with trees and obstructions possibly blocking a good view, the moon may not be well seen until about 6:30 p.m. Mid-eclipse is at 6:48 p.m. when the subtle shading on the lower half of the moon should be easily noticeable. This slight darkening will be detectable until about 8 p.m. If the weather cooperates, try to catch this event, and maybe even share the experience with family or friends! The Total Solar Eclipse occurs on March 29, but is NOT VISIBLE AT ALL FROM ANY PART OF NORTH AMERICA . Those who wish to experience this awesome spectacle will be traveling to North Africa, the Eastern Mediterranean, Turkey, or Southern Russia .

More information about these and other events for observation is available in the latest edition of the book The Beginner’s Observing Guide, which is available at Sharbot Lake Pharmacy.