Friday, June 15
Saturday, June 16
Sunday, June 17
Monday, June 18
Tuesday, June 19
Wednesday, June 20
If you have a good view of the west-northwest horizon (from mid-northern latitudes), mark precisely where the Sun sets. In a few days you should be able to detect that it's again starting to set a little south of this point. Build your own Stonehenge?
Thursday, June 21
Friday, June 22
Saturday, June 23
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'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 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
Mercury (about magnitude –0.3 and fading) is very low in the west-northwest about 30 or 40 minutes after sundown. Don't confuse it with Capella far to its right, in the northwest. Pollux and Castor are above Mercury early in the week, and to the right of it by June 23rd.
Venus (magnitude –4.3), after transiting the Sun on June 5th, is now deep in the glow of dawn. Look for it low in the east-northeast before sunrise. Don't confuse Venus with Jupiter to its upper right. The two planets are 9° apart on the morning of June 16th and 6° apart on June 23rd.
Below or lower right of Venus twinkles much fainter Aldebaran; use binoculars as daybreak brightens. Jupiter and Venus, the two brightest planets, are on their way up for a grand showing in the morning sky this summer.
Mars (magnitude +0.7, crossing from Leo into Virgo) shines orange in the southwest at dusk and lower in the west as evening grows late. This week Mars creeps to the halfway point from Regulus (off to its lower right) to the Saturn-and-Spica pair (left). Mars will shoot the gap between Saturn and Spica in mid-August.
In a telescope Mars is gibbous and tiny (7 arcseconds wide), continuing to fade and shrink.
Jupiter (magnitude –2.0) is coming into view deep in the glow of dawn. See Venus above.
Saturn (magnitude +0.6, in Virgo) shines fairly high in the south-southwest as twilight fades. Below it by 5° is Spica. Later after dark they move lower to the southwest.
Uranus (magnitude 5.9, at the Pisces-Cetus border) is well up in the east-southeast before the first light of dawn.
Neptune (magnitude 7.9, in Aquarius) is very well up in the south-southeast before dawn. Finder charts for Uranus and Neptune.
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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