This Week's Sky at a Glance
Some daily events in the changing sky for March 23 – 30
Saturday, March 24
Sunday, March 25
Monday, March 26
Coincidentally, Venus is at its greatest elongation: 46° east of the Sun. That makes this the very best possible time to spot Venus during daylight hours.
Tuesday, March 27
Wednesday, March 28
Thursday, March 29
Friday, March 30
Saturday, March 31
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 Astronomybooklet (which only has bimonthly maps).
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 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 classic if dated Burnham's Celestial Handbook.Can a computerized telescope replace charts? I don't think so — not for beginners, anyway, and especially not on mounts and tripods are less than top-quality mechanically (able to point with better than 0.2° repeatability). 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
Mercury is hidden deep in the glow of sunrise.
Venus and Jupiter are moving apart now but still form a spectacular pair in the western evening sky. They're 9° apart on March 23th and 14&@176; apart by the 30th. Venus is the brighter one, on top. It will stay about the same height at dusk well into April, but Jupiter is sinking ever lower. These are the two brightest celestial objects after the Sun and Moon, being magnitudes –4.5 and –2.1 right now, respectively.
Venus is at greatest elongation this week (exact on March 26th). For skywatchers at mid-northern latitudes, this is Venus's highest showing in its 8-year cycle of apparitions.
In a telescope Venus is now a bit less than half lit and 23 arcseconds tall. Jupiter shows a much lower surface brightness, being farther from the Sun, but its apparent diameter is somewhat larger: 32″ (though this is small for Jupiter).
Mars (magnitude –0.9) shines bright fire-orange under the belly of Leo. Fainter Regulus is 6° or 7° to its upper right in early evening, and Gamma Leonis is farther above it.
Mars was at opposition on March 3rd. Now it's fading and shrinking a bit as Earth pulls ahead of it along our faster, inside-track orbit around the Sun. But at least Mars is shining higher in the evening sky now, reaching a good altitude for telescopic observing at a convenient hour. It's highest in the south by around 11 p.m. daylight-saving time.
In a telescope Mars is 13.0 arcseconds wide. It won't appear this big and close again until 2014. Notice the much shrunken little North Polar Cap; spring is giving way to summer in Mars's northern hemisphere. See our Mars map and observing guide in the April Sky & Telescope, page 50.
Saturn (magnitude +0.3, in Virgo) rises in the east around the end of twilight and glows highest in the south around 2 a.m. Shining 6° to its right is Spica, about half as bright at magnitude +1.0 and bluer. In a telescope Saturn's rings are tilted 14° from our line of sight.
Uranus and Neptune are hidden in the sunrise.
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 Daylight Time (EDT) equals Universal Time (also known as UT, UTC, or GMT) minus 4 hours.
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