Friday, August 15
For the next several mornings, look low in the east-northeast about 45 to 30 minutes before sunrise for Venus and Jupiter very close together. On Saturday morning, these two brightest planets are still 2° apart, as shown at right. They'll be closest on Monday morning the 18th: just 0.2° or 0.25° apart at the time of dawn for Europe, 0.3° by the time dawn reaches the Americas. See our article, Venus-Jupiter Spectacle Coming August 18th.
Saturday, August 16
The two brightest stars of summer are Vega, overhead right after dark, and Arcturus, shining in the west. Vega is a white-hot type-A star 25 light-years away. Arcturus is an orange-yellow-hot type-K giant 37 light-years distant. Their color difference is fairly clear to the unaided eye. Both are dozens of times more luminous than the Sun.
Sunday, August 17
As dawn brightens on Monday morning, look for Jupiter and Venus having their very close conjunction low in the east-northeast, 0.2° or 0.3° apart, as shown below. The best view should be about 60 to 30 minutes before your local sunrise time.
The Moon is at last quarter (exact at 8:26 a.m. on the 17th EDT). It shines high in the southeast in early dawn on this date, with the Pleiades roughly a fist-width at arm's length to its left and a bit higher.
Monday, August 18
Look northeast as soon as the stars come out for W-shaped Cassiopeia. In twilight it's not quite as high as the Big Dipper is in the northwest, but right after dark, Cassiopeia and the Dipper reach their balance point. Summer is nearing its end.
Tuesday, August 19
If you're in the Earth's mid-northern latitudes, bright Vega passes close by your zenith just as night becomes fully dark. Whenever you see Vega at its closest to straight up, you know that Sagittarius, with its deep-sky riches, is at its highest in the south.
Wednesday, August 20
Roam the deep-sky sights just above the Sagittarius Teapot pattern with Sue French's "Deep-Sky Wonders" guided tour in the August Sky & Telescope, page 56. Do you know the Summer Christmas Tree?
Thursday, August 21
As soon as the stars come out, the Great Square of Pegasus stands low in the east. It's balancing on one corner, and your fist at arm's length fits inside it. It rises higher through the evening and floats highest overhead around 2 or 3 a.m.
Friday, August 22
Altair is the brightest star halfway up the southeastern sky after nightfall. Look to its left, by a little more than a fist at arm's length, for the dim but distinctive constellation Delphinus, the Dolphin. He's leaping to the left, just below the Milky Way.
Saturday, August 23
August is prime Milky Way time. After dark, the Milky Way runs from Sagittarius and Scorpius in the south-southwest, up and left across Aquila and through the big Summer Triangle very high in the southeast and east, and on down through Cassiopeia to Perseus rising low in the north-northeast.
Want to become a better astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.
This is an outdoor nature hobby; 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 guide to 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 once you know your way around, the even larger Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts with a telescope.
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 beloved if dated Burnham's Celestial Handbook.
Can a computerized telescope replace charts? Not for beginners, I don't think, and not on mounts and tripods that are less than top-quality mechanically (able to point with better than 0.2° repeatability, which means fairly heavy and expensive). 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 sunset.
Venus (magnitude –3.8) and Jupiter (a sixth as bright at magnitude –1.8) shine close together low in the east-northeast during dawn all week. They appear closest together in conjunction on Monday the 18th, just 0.2° or 0.3° apart. See our article, Venus-Jupiter Spectacle Coming August 18th.
Mars and Saturn, both magnitude +0.6, glow in the southwest at dusk. Mars is the lower one. They're drawing closer together every day. On Friday the 15th they're still 6½° apart. They'll pass 3½° apart on August 23–26.
Between them early in the week is the wide binocular double star Alpha Librae, magnitudes 2.8 and 5.2. Later it moves to their right.
Uranus (magnitude 5.8 in Pisces) and Neptune (magnitude 7.8 in Aquarius) are well placed in the southern sky in the early-morning hours. 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) is Universal Time (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