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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).
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 your 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
Mercury (about magnitude –0.2) is low in the glow of sunset. Look far to the lower right of Venus.
Venus (magnitude –4.2, in Leo) is the bright Evening Star sinking in the west as twilight fades. Between Venus and Mercury, can you see fainter Regulus?
Mars (magnitude +1.4, at the Leo-Virgo border) is upper left of Venus. Watch Mars closing in on Saturn to its upper left day by day. In a telescope Mars is just a tiny blob 5 arcseconds in diameter.
Jupiter (magnitude –2.6, in Pisces) rises around 11 p.m. daylight saving time. It shines high in the southeast in the early morning hours and reaches its highest point in the south during early dawn. It's the brightest starlike point in the morning sky.
Saturn (magnitude +1.1, in the head of Virgo) is in the west during evening, just upper left of slightly dimmer Mars. The diagonal line of Saturn, Mars, Venus, Regulus and Mercury continues to shrink. The first three of these planets will bunch up low in the sunset in early August.
Uranus (magnitude 5.8, in Pisces) is 3° west of Jupiter. In a telescope Uranus is only 3.6 arcseconds wide, compared to Jupiter's 44″.
Neptune (magnitude 7.8, at the Aquarius-Capricornus border) is up in good view by midnight, well to Jupiter's west. See our finder charts for Uranus and Neptune in 2010.
Pluto (magnitude 14, in northwestern Sagittarius) is high in the south-southeast after dark. See our big Pluto finder charts for 2010 — though the moonlight interferes with such a faint object this week.
All descriptions that relate to your horizon or zenith — 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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