Sky at a Glance | March 8th, 2013

Saturday, March 9

And, you may know that if you follow the curve of the Dipper's handle out and around by a little more than a Dipper length, you'll arc to Arcturus, now rising in the east.

But did you know that if you follow the Pointers backward the opposite way, you'll land in Leo?

Draw a line diagonally across the Dipper's bowl from where the handle is attached, continue far on, and you'll go to Gemini.

And look at the two stars forming the open top of the Dipper's bowl. Follow this line past the bowl's lip far across the sky, and you crash into Capella.

Sunday, March 10

Monday, March 11

Using binoculars, look below Sirius by almost a binocular field-of-view for a dimly glowing patch among the stars. This is the open star cluster M41, 2,200 light-years away.

Bring binoculars to pick the comet out of the twilight low in the west. (Don't expect it to look this obvious!) The scene is drawn for about 40° north latitude, and the Moon is placed for a viewer near the middle of North America.

You're welcome to reprint this illustration anywhere, but include a credit to Sky & Telescope magazine and a link to SkyandTelescope.com. Click here for the high-res version.

Sky & Telescope diagram

Tuesday, March 12

And think photo opportunity! Use a long or zoomed-out lens, and put your camera on a tripod because with a long lens in twilight, exposures won't be short. Experiment with a variety of exposures.

Wednesday, March 13

Thursday, March 14

Watch the Moon wax to, and through, the evening Jupiter group. (Drawn for the middle of North America. European observers: move each Moon symbol a quarter of the way toward the one for the previous date. The Moon is shown three times its actual size.)

Sky & Telescope

Friday, March 15

Saturday, March 16

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 guide to astronomy. Or download our free Getting Started in Astronomy booklet (which only has bimonthly maps).

The Pocket Sky Atlas plots 30,796 stars to magnitude 7.6 — which may sound like a lot, but that's less than one star in an entire telescopic field of view, on average. By comparison, Sky Atlas 2000.0 plots 81,312 stars to magnitude 8.5, typically one or two stars per telescopic field. Both atlases include many hundreds of deep-sky targets — galaxies, star clusters, and nebulae — to hunt among the stars.

Sky & Telescope

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

You'll also want a good deep-sky guidebook, such as Sue French's Deep-Sky Wonders collection (which includes its own charts), Sky Atlas 2000.0 Companion by Strong and Sinnott, the bigger Night Sky Observer's Guide by Kepple and Sanner, or the beloved if dated Burnham's Celestial Handbook.

Can a computerized telescope replace charts? Not for beginners, I don't think, and certainly not on mounts and tripods that are less than top-quality mechanically (able to point with better than 0.2° repeatability). As Terence Dickinson and Alan Dyer say in their invaluable 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

As Jupiter shrinks into the distance, its most striking characteristic in amateur telescopes is the single, broad South Equatorial Belt (above center) contrasting with the paired North Equatorial and North Temperate Belts. South here is up. Note the Great Red Spot at right, in a well-defined white Red Spot Hollow. Compare it to the slightly smaller and paler orange Oval BA left of the central meridian. Blue festoons mark the north edge of the bright Equatorial Zone but not its south edge.

Christopher Go

Mercury, Venus, and Mars are hidden in the glare of the Sun.

Jupiter (bright at magnitude –2.3, in Taurus) comes into view high in the southwest after sunset and dominates the southwest to west later in the evening. Left of Jupiter is orange Aldebaran. Farther to Jupiter's lower right are the Pleiades. They all set in the west-northwest around the middle of the night.

In a telescope, Jupiter is shrinking as Earth pulls farther ahead of it in our faster orbit around the Sun. This week it shrinks from 38 to 37 arcseconds wide.

Saturn (magnitude +0.4, in Libra) rises in the east-southeast in late evening now. Watch for it to rise well to the lower left of Spica and farther to the lower right of brighter Arcturus. Saturn shines highest in the south in the early morning hours — more or less between Spica to its right and Antares farther to its lower left.

Saturn on March 2, 2013, imaged by Christopher Go. South is up. Note the bright Equatorial Zone and, tougher to see, the thin whitish band at mid-northern latitudes: the last remnant of the great white storm that broke out at this latitude in December 2010.

Christopher Go

Uranus and Neptune are lost in 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. Eastern Daylight Time (EDT) is UT minus 4 hours.