Some daily events in the changing sky for August 21 – 29.
Friday, August 21
Saturday, August 22
Sunday, August 23
Monday, August 24
Tuesday, August 25
Wednesday, August 26
Thursday, August 27
Update: David Dunham of the International Occultation Timing Association (IOTA) writes that this will be "our last occultation of Antares until 2023." At locations where the Moon is reasonably high "this occultation should be visible with any small telescope, weather permitting." Accuweather predicts "only scattered clouds in the narrow graze zone that crosses northern New York and Massachusetts, including part of the Boston area. Let me know if you might be interested in joining an expedition to observe the graze." Dunham's email is dunham AT starpower DOT net.
Friday, August 28
Saturday, August 29
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 middle of each Sky & Telescope diagram" target="new_window">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 Sky Atlas 2000.0 or the smaller Pocket Sky Atlas) and good deep-sky guidebooks (such as Sky Atlas 2000.0 Companion by Strong and Sinnott, the more detailed and descriptive Night Sky Observer's Guide by Kepple and Sanner, or the classic Burnham's Celestial Handbook). Read how to use them effectively.
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 and a curious mind." Without these, "the sky never becomes a friendly place."
More beginners' tips: "How to Start Right in Astronomy".
This Week's Planet Roundup
Mercury and Saturn (magnitudes 0.2 and 1.1, respectively) are deep in bright twilight just above the horizon due west. Try scanning for them with binoculars, preferably tripod-mounted, 20 or 30 minutes after sunset. Saturn is off to the right of brighter Mercury. Good luck.
Venus (magnitude –4.0, moving from Gemini into Cancer) blazes in the east before and during dawn.
Mars (magnitude +1.0, between Orion and Auriga) is high to the upper right of Venus before dawn. To its own upper right is similar-looking Aldebaran. To its lower right is similarly colored Betelgeuse.
Jupiter (magnitude –2.9, in Capricornus) is just past opposition. It comes into view low in the southeast in twilight — the first "star" to appear after sunset. It's higher in better telescopic view by 11 p.m.
Jupiter impact mark fading. A black dust marking, like those made by the Comet Shoemaker-Levy 9 impacts in 1994, appeared suddenly in Jupiter's south polar region around July 18th. Backyard observers tracked it as it spread and elongated. By August 17th it had broken up and faded nearly to invisibility.
Uranus (magnitude 5.8, just below the Circlet of Pisces) is well up in the southeast by 10 or 11 p.m.
Neptune (magnitude 7.8, in Capricornus) appears 4° from Jupiter but 20,000 times fainter. See our finder charts for Uranus and Neptune.
Pluto (14th magnitude, in northwestern Sagittarius) is highest in the south-southwest just after dark. See the finder chart in the June Sky & Telescope, page 53.
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.
To be sure to get the current Sky at a Glance, bookmark this URL:
If pictures fail to load, refresh the page. If they still fail to load, change the 1 at the end of the URL to any other character and try again.