Friday, April 30
Saturday, May 1
Sunday, May 2
Monday, May 3
Tuesday, May 4
Wednesday, May 5
Thursday, May 6
Friday, May 7
Saturday, May 8
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 is hidden in the glare of the Sun.
Venus (magnitude –3.9, in Taurus) shines brightly in the west-northwest during twilight. Look for Aldebaran (magnitude +1.0) to its left early in the week, and lower left of it later. Capella (magnitude +0.1) shines much higher to Venus's upper right.
Mars, dimming farther away into the distance at magnitude +0.8 now, is in Cancer high in the southwest to west during evening. In a telescope Mars is tiny, shrinking from 7.3 to 6.9 arcseconds in diameter this week.
Jupiter (magnitude –2.1) shines low before dawn; look east about an hour before your local sunrise time. No other point there is nearly so bright!
Saturn (magnitude +0.8, in the head of Virgo) is high in the south to southwest during evening. In a telescope Saturn's rings are tilted a mere 1.9° from edge-on, practically at the minimum inclination of 1.7° that they will display from mid-May through early June. Note the fine black shadow-line they cast on Saturn's disk! Now is also a good time to try for the more difficult of Saturn's moons with your telescope; see the May Sky & Telescope, page 61.
Uranus and Neptune are still low before sunrise. Wait another few weeks.
Neptune, however, is passing a historic milestone this season. For the first time since it was discovered in 1846, Neptune has completed a full circuit of the sky and has returned very close to the point (near the Aquarius-Capricornus border) where Johann Galle first spotted it from Berlin Observatory on September 23rd of that year — following a prediction by Urbain Le Verrier in France that a new planet ought to be there, based on gravitational perturbations of Uranus. See The Return of Neptune.
Pluto (magnitude 14, in northwestern Sagittarius) is highest in the south before dawn.
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.
"The universe is full of magical things patiently waiting for our wits to grow sharper."
— Eden Phillpotts, "A Shadow Passes," 1918
"Science is built up of facts, as a house is with stones. But a collection of facts is no more a science than a heap of stones is a house."
— Henri Poincaré (1854–1912)
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