Abrams Planetarium

SKYWATCHER'S DIARY: March 1995

TO THE READER

The Skywatcher's Diary for March 1995 has been prepared by David Nette and Robert Victor. Credit to Abrams Planetarium, Department of Physics and Astronomy at Michigan State University would be appreciated. Our illustrated Sky Calendar accompanies the printed version of Skywatcher's Diary as it is sent monthly to Michigan newspapers, but does not accompany this Internet version. If you would like a sample copy, send your request with a self-addressed, stamped envelope to

Sky Calendar
Abrams Planetarium
Michigan State University
East Lansing, MI 48824

This month's most striking sights include two young moons, an easy one at dusk on March 2, and a more difficult one shortly after sunset on March 31. Gatherings involving the moon passing near planets and bright stars occur on the evenings of March 8, 11-14 and 18, and the mornings of March 22, 27 and 28. Morning events are mentioned in Skywatcher's Diary one day prior to the event.)


Wednesday, March 1

The moon, New today at 6:48 a.m. EST, appears too near the Sun to be seen today from anywhere in U.S., except possibly Hawaii shortly after sunset. This year, both January and March have two New Moons, a circumstance which won't repeat until the year 2014. Take advantage of the absence of bright moonlight to view the Orion Nebula still high in the sky, and to get a last look at Andromeda Galaxy at nightfall before it departs for the season.

Thursday, March 2

Forty-five minutes after sunset the young moon is an easy sight very low in west. Note the thin sunlit crescent is oriented as if it's "holding water" in its bowl. Look also for earthshine, or sunlight reflected from Earth onto the "dark" portion of the moon's disk. Follow the moon nightly about 3/4 hours after sunset now until March 16, and you'll notice day by day it's traveling along a steeply inclined path.

Friday, March 3

Look low in the W an hour after sunset for the waxing crescent moon. At least three corner stars of the Great Square of Pegasus can be seen to the right of the moon: Begin with 3rd-magnitude Gamma Pegasi 11 degrees to the moon's right, then find 2nd-mag Alpha Andromedae 14 degrees upper right of Gamma Peg, and 2nd-mag Beta Peg 14 degrees lower right of Alpha And. To find Andromeda Galaxy, first locate 2nd-mag Beta And 14 degrees above and slightly left of Alpha And. Then use binoculars to look for a hazy patch 8 degrees right of Beta And.

Saturday, March 4

At nightfall the moon is well up in W. Second-magnitude Hamal, or Alpha in Aries the Ram, shines 15 degrees to the moon's upper right, with 3rd-mag Beta Ari 4 degrees below it, and 4th-mag Gamma Ari 1.5 degrees lower left of Beta. The variable star Mira, brightening toward its April maximum, is 18 degrees left of the moon. How bright is Mira tonight? (Its brightness cannot be forecast accurately; it might not even be visible to the unaided eye.)

For more information on observing stars which vary in brightness, write AAVSO (American Association of Variable Star Observers), 25 Birch Street, Cambridge, MA 02138.

Sunday, March 5

An hour after sunset the moon is in the WSW. The brightest stars of Aries the Ram shine 10 degrees right of the crescent moon. Saturn is in conjunction with the Sun today. Viewers in Hawaii and southernmost Florida and Texas can look for Saturn low in eastern morning sky near month's end. The rest of the country will have to wait until April.

Monday, March 6

The rest of this week is excellent for scanning the moon's terminator, or day-night boundary, with binoculars or a telescope. Tonight the Sun rises on the crater Theophilus, causing its walls and central peak to cast long shadows. Look nightly, and watch for changes!

For viewers with telescopes, Mars is not an easy object for study, presenting a disk now only a third the size of Jupiter's. Beginners can look for Syrtis Major, Mars' most prominent dark marking, near the center of the disk tonight at 7:10 p.m. EST, and about 37 minutes later on each successive night. Can you see the north polar cap shrinking rapidly in the Martian spring? This month, Mars' north pole is tipped 17 degrees toward Earth. You can tell which is the north limb of Mars by nudging the telescope toward the North Star; as Mars goes out of the field, its north limb will be the last to depart.

Tuesday, March 7

Face WSW at nightfall to see the moon with the Pleiades, or Seven Sisters, 7 degrees to upper right. Reddish 1st-magnitude Aldebaran, eye of Taurus, is 9 degrees to moon's upper left. Binoculars give fine views of the Pleiades, and of a wider cluster, the Hyades, between the moon and Aldebaran. Turn your binoculars toward the moon to see two gaping craters, Aristoteles and Eudoxus, along the upper part of the moon's terminator, or day-night boundary.

Wednesday, March 8

The moon, approaching First Quarter, is in the SW at dusk with ruddy Aldebaran 4 degrees to its lower right. Use binoculars or a telescope to see the large crater Albategnius just below the midpoint of the moon's terminator (day-night boundary), with the smaller newer crater Klein interrupting the first crater's wall. Can you detect Klein's central peak? Watch for several hours as the Sun, rising slowly over the lunar landscape, slowly illuminates more of the scene.

Thursday, March 9

At dusk the moon is high in the south. Betelgeuse, in Orion, is 12 degrees lower left of the waxing gibbous moon, while third-magnitude Zeta Tauri, the bull's southern horn, is 2 degrees to moon's upper right. The Apennine lunar "mountains" (actually the wall of huge Mare Imbrium, Sea of Showers) show well in binoculars tonight. Watch for the emergence of the young crater Eratosthenes at the end of the "mountain chain", as the Sun rises slowly over the lunar landscape. How soon can you see Eratosthenes' central peak?

Friday, March 10

Dusk finds the gibbous moon high in the SSE, with Betelgeuse, the bright shoulder of Orion, shining 14 degrees to its lower right. Binoculars and telescopes show the spectacular crater Copernicus just above the midpoint of the moon's day-night boundary. It's fascinating to use high power to follow changes for several hours as the Sun illuminates more of the floor of this 60-mile wide crater.

Saturday, March 11

An hour after sunset the moon is in the SE with the Gemini Twins, Pollux and Castor, 12 to 15 degrees to its upper left. Procyon, the Little Dog Star, shines 12 degrees lower left of the moon.

Sunday, March 12

The waxing gibbous moon is high in SE an hour after sundown with Procyon, in Canis Minor, 12 degrees to its lower right. Ruddy Mars, outshining Procyon by more than a magnitude, is 15 degrees lower left of the moon. Watch Mars fade to equal Procyon by late April.

Monday, March 13

The moon is in the ESE at dusk. Reddish Mars lies 9 degrees upper left of the moon, while Regulus, the heart of Leo the lion, is 15 degrees to moon's lower left.

Tuesday, March 14

The moon is in ESE at dusk and has passed well below ruddy Mars. Look for the planet shining steadily 17 degrees above the moon. Regulus, in the Sickle of Leo the lion, is 6 degrees left of the moon.

Wednesday, March 15

The moon, approaching Full, is in the ESE an hour after sundown. Look for a bluish, first magnitude star 14 degrees above the moon. This is Regulus, the heart of Leo. Denebola, marking the tip of Leo's tail, is 19 degrees to moon's lower left.

Thursday, March 16

An hour after sunset the Full "Sap" Moon is low in E to ESE, with Regulus 27 degrees upper right. Second-magnitude Denebola, tail of Leo, is 17 degrees to moon's upper left. For the rest of the week, the moon rises 1-1/4 hours later each night from northern U.S., an hour later nightly from southern U.S. By Saturday, the moon rises after darkness falls.

Friday, March 17

Three hours after sundown the waning gibbous moon is in ESE, with 1st-magnitude Spica 12 degrees to its lower left. The moon moves east against background stars an average of 13 degrees daily. Can you guess where will moon appear at this hour on Saturday?

Saturday, March 18

Three hours after sunset, the moon is low in the ESE and has passed Spica, now 2 degrees to moon's upper right. Spica marks the ear of wheat in the hand of Virgo. Arcturus shines far to the moon's upper left.

Sunday, March 19

The waning gibbous moon is just risen in ESE four hours after sundown. First magnitude Spica shines 17 degrees to the moon's upper right.

Monday, March 20

The vernal equinox occurs at 9:14 p.m. EST, initiating spring as the Sun passes directly over Earth's equator. An hour before sunup Tuesday the moon approaches the head of Scorpius. Look for bright Jupiter within 17 degrees to moon's left, and Antares, the heart of the scorpion, 12 degrees to moon's lower left. The head of Scorpius is a slightly curved, nearly vertical line of three stars of 2nd and 3rd magnitude between Antares and the moon.

Tuesday, March 21

At dawn Wednesday the moon pulls close to bright Jupiter in the south. Jupiter is 2 to 3 degrees lower left of the moon, while reddish Antares is 8 degrees to their lower right.

Wednesday, March 22

At dawn Thursday the moon, approaching Last Quarter and so still just over half full, has passed bright Jupiter low in the S. Jupiter is 12 degrees right of the moon, while reddish Antares shines 8 degrees lower right of Jupiter.

Thursday, March 23

Look for the Red Planet Mars high in SE at nightfall. Note Regulus 17 degrees lower left of Mars, and use binoculars to see the Beehive Cluster 6 degrees to Mars' upper right. Mars now resumes eastward motion against the stars, and will pass only 1 degree north of Regulus on May 24. Keep watch until then!

Friday, March 24

An hour after sunset the familiar constellation Orion is well up in SW. Betelgeuse marks the bright shoulder of the Hunter, three bright stars in a row form his belt, and two bright stars below the belt, Rigel and Saiph, mark the Hunter's feet. Sirius, the brightest nighttime star, is found by extending a line along the belt stars to their left.

Saturday, March 25

Sunday about 45 minutes before sunup, the thin crescent moon is in SE. Brilliant Venus is very low in ESE, 19 degrees to moon's lower left, and bright Jupiter is just west of due south. These two planets are now 72 degrees apart, and will continue spreading farther apart until June.

Skywatchers in Hawaii and southernmost Florida and Texas can use binoculars to search for Mercury and Saturn less than 1 degree apart, rising in bright twilight 20 degrees lower left of Venus. Mercury is the lower and brighter of the close pair.

Sunday, March 26

An hour before sunup Monday the thinning crescent moon is low in ESE. Brilliant Venus is 8 degrees lower left of the thin crescent. For the next few mornings, note earthshine, or sunlight reflected from Earth onto the "dark" portion of the moon's disk.

Monday, March 27

Find the still very easy old moon very low in ESE 45 minutes before sunup Tuesday, with brilliant Venus 7 degrees lower right.

Tuesday, March 28

Here's another chance to see the old moon, but you must look in bright morning twilight. About 30 to 40 minutes before sunup, look for the very thin crescent very low, just south of due east, 18 degrees lower left of Venus.

From southernmost parts of Florida and Texas, use binoculars to search for Saturn 5 degrees to moon's lower right. From Hawaii, Saturn is 6 degrees to the moon's right.

Wednesday, March 29

Make a checklist of winter's bright stars, Rigel, Aldebaran, Sirius, Betelgeuse, Procyon, Pollux, Castor, and Capella, and check them off daily as you observe them each clear evening at dusk. They're all easy to see now, but by late April Rigel will become difficult to spot, and during May we'll lose Aldebaran, Sirius, and Betelgeuse. Keep looking through June, and watch for the "heliacal settings" (seasonal disappearances) of these stars into the western twilight glow.

Thursday, March 30

The moon is New at 9:09 p.m. EST (6:09 p.m. PST), and not visible until just after sunset Friday. The moon's age will then be 21-22 hours from the East Coast, 24-25 hours from the West. Select a site where you can enjoy an unobstructed view of sunset, and don't miss tomorrow night's challenging Young Moon!

Friday, March 31

Here's a challenge to sharpen your observational skills -- to see a younger and thinner crescent moon than the vast majority of skywatchers have ever seen.

From a place with an unobstructed western horizon, note the Sun's location in relation to landscape features just as the solar disk rests on the horizon. (If you have a perfect horizon, this would happen 6 degrees north of due west, 3 minutes before the calculated time of sunset.) Note the time when the sun's disk rests on your horizon, and wait 14 minutes. The moon should then have the same azimuth (direction) as the Sun did 14 minutes earlier, except that the moon will be nearly 7 degrees higher. If at first you don't see the moon with unaided eye, try with binoculars. The hairline thin crescent will have horns pointing nearly upward, and noticeably less than half its circumference will be illuminated by the Sun. This may be noted by imagining the moon's disk as a clock face, and estimating the location of the end points of the crescent on the imaginary clock. For example, the crescent may be lit from 3 o'clock to 8 o'clock.

The above data is calculated for southern Michigan, where moon's age will be only about 22 hours after New. The above details vary from place to place within the U.S., but wherever you are, if the sky is very clear, you should be able to follow the moon for another 20 to 30 minutes as it moves down and to the right and eventually sets.

If you see the moon this evening, note the times when you first spot it, both with optical aid and with the unaided eye, and calculate its age at each sighting. The Moon was New on Thursday at 9:09 p.m. EST, or 6:09 p.m. PST.


HTML by Michael. Updated 24 May 1996 by Jenny Pon