Sky at a Glance | March 4th, 2011

Friday, March 4

  • Early March is when Sirius, the brightest star in the night sky, shines at its highest due south right after dark. It's the bottom point of the equilateral Winter Triangle. The triangle's other points are orange-red Betelgeuse to the upper right, and Procyon to Sirius's upper left.

  • New Moon (exact at 3:46 p.m. EST).

  • Algol is at minimum brightness, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 8:53 p.m. Eastern Standard Time.

    Soon after sunset!
    Mercury is a challenge low in bright twilight! Jupiter helps guide the way. The visibility of objects near the horizon is exaggerated here.

    Saturday, March 5

  • If the sky is clear very low in the west soon after sunset, binoculars may show Mercury lower left of the very thin waxing crescent Moon, as shown here. Brighter Jupiter higher up guides the way to them. Bring binoculars. Could this be the youngest Moon you've ever seen? Determine its age from the time of new Moon listed under Friday above.

    Sunday, March 6

  • Jupiter shines to the left of the waxing crescent Moon in twilight, as shown here. If you're near latitude 40° north, the crescent is almost exactly level like a cup.

    Monday, March 7

  • The crescent Moon poses above Jupiter at dusk, as shown here.

    Tuesday, March 8

  • The crescent Moon, thickening as it moves farther from our line of sight to the Sun, shines higher above Jupiter now at dusk.

  • Late tonight an 8th-magnitude star in Leo should be occulted (covered) by the 12th-magnitude asteroid 72 Feronia as seen from a narrow track from the Florida Keys across Louisiana to Oregon. The star may be blacked out for up to 7 seconds. See map, finder charts, and more information.

    Wednesday, March 9

  • Look northeast after dark to spot the Big Dipper, standing on its handle. Follow the curve of the handle on around to the lower right, by a little more than a Dipper-length, to see where bright Arcturus will rise as the evening advances.

    Thursday, March 10

  • The Pleiades cluster glimmers above or upper right of the Moon this evening. If the Moon's glare interferes, move the Moon behind a tree limb or roofline.

    Friday, March 11

  • Look lower left of the Moon this evening for Aldebaran, an orange giant star 65 light-years away. About three times farther to the Moon's upper right shines brighter Capella, 42 light-years distant.

    Saturday, March 12

  • First-quarter Moon (exact at 6:45 p.m. Eastern Standard Time).

  • Daylight saving time begins at 2 a.m. Sunday morning for most of the U.S. and Canada.



    Sky at a Glance is now an iPhone app! Put S&T SkyWeek on your iPhone, iPad, or iPod Touch and get the above listings anytime, anywhere — with interactive sky maps! Tap a button to see the scene described, customized for your location worldwide. From there you can scroll the view all around the sky, zoom in or out, change to any time or date, and turn on animation.

    Go to Apple's iTunes store from your device and find S&T SkyWeek.


    Want to become a better amateur astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.

    For an easy-to-use constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential magazine of astronomy. Or download our free Getting Started in Astronomy booklet (which only has bimonthly maps).

    Sky Atlas 2000.0 (the color Deluxe Edition is shown here) plots 81,312 stars to magnitude 8.5. That includes most of the stars that you can see in a good finderscope, and typically one or two stars that will fall within a 50× telescope's field of view wherever you point. About 2,700 deep-sky objects to hunt are plotted among the stars.
    Alan MacRobert

    Once you get a telescope, to put it to good use you
    must have a detailed, large-scale sky atlas (set of charts). The standards are the Pocket Sky Atlas, which shows stars to magnitude 7.6; the larger Sky Atlas 2000.0 (stars to magnitude 8.5); and the even larger and deeper Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts effectively.

    You'll also want a good deep-sky guidebook, such as Sky Atlas 2000.0 Companion by Strong and Sinnott, or the more detailed and descriptive Night Sky Observer's Guide by Kepple and Sanner, or the classic if dated Burnham's Celestial Handbook.

    Can a computerized telescope take their place? I don't think so — not for beginners, anyway, and especially not on mounts that are less than top-quality mechanically. As Terence Dickinson and Alan Dyer say in their Backyard Astronomer's Guide, "A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand."


    This Week's Planet Roundup

    Saturn on Feb. 6, 2011
    Saturn's dispersing white spot "looks like a comet," wrote Christopher Go. As of March 2nd its head had moved far around the planet to about System III longitude 120°. This image (taken February 6th) exaggerates its contrast. South is up. Click for animation of several images spanning 33 minutes of Saturn's rotation. And see an even more awesome Cassini image.

    Mercury (about magnitude
    –1.4) is emerging very low in the western twilight. Look for it to the lower right of Jupiter, as soon after sunset as you can pick Jupiter up. The later in the week the better — Mercury moves rapidly higher each day.

    Venus (magnitude –4.1, in Capricornus) shines low in the southeast during dawn.

    Mars is out of sight behind the glare of the Sun. It will remain so for about the next three months.

    Jupiter (magnitude –2.1, at the Pisces-Cetus border) is getting lower in the west every day. Look for it there as twilight deepens. It sets right after dark.

    Saturn on Feb. 11, 2011
    The other side of Saturn, imaged by Go on February 11th. The dark, reddish South Equatorial Belt can be seen just south of the ring. South is up.

    Saturn (magnitude +0.5, in Virgo) rises around 8 or 9 p.m., but it's best seen in a telescope much later in the night when it gains high altitude. It's highest in the south around 2 a.m. Spica, slightly fainter, shines about 10° below Saturn all evening and into the early morning hours.

    In a telescope, Saturn's months-old white spot has spread into a streak far around the planet, as seen here. Saturn's rings are 10° from edge on. See how many of Saturn's satellites you can identify in your scope using our Saturn's Moons tracker.

    Uranus and Neptune are lost from view behind the glare of the Sun.


    All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's mid-northern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America. Eastern Standard Time (EST) equals Universal Time (also known as UT, UTC, or GMT) minus 5 hours.


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