Some daily events in the changing sky for August 17 – 25.
Friday, August 17
Saturday, August 18
Sunday, August 19
Monday, August 20
Tuesday, August 21
Wednesday, August 22
Thursday, August 23
Friday, August 24
Saturday, August 25
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 foldout map in 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 maps; the standard is Sky Atlas 2000.0) and good deep-sky guidebooks (such as Sky Atlas 2000.0 Companion or the enchanting though somewhat dated Burnham's Celestial Handbook). Read here how to use them effectively.
More beginners' tips: "How to Start Right in Astronomy".
This Week's Planet Roundup
Mercury and Venus are deep in the glare of the Sun.
Mars (magnitude +0.4, in Taurus) rises around midnight or 1 a.m. daylight saving time and shines very high in the east before dawn. It's near twinkly Aldebaran, which is similarly colored but less bright. Look above them for the Pleiades. In a telescope Mars is 8 arcseconds in diameter, half the size it will be around its Christmas-season opposition.
Incidentally: if friends or family tell you they've read that Mars will become as big and bright as the full Moon in late August, point them to our article about the regular-as-clockwork August Mars Hoax.
Jupiter (magnitude –2.3, in southern Ophiuchus) glares in the south-southwest during twilight and lower in the southwest later after dark. Get your telescope on it as early in the evening as you can. Antares, less bright, sparkles redly 5° below Jupiter; the two have been companions all summer. Other stars of Scorpius shine below them and to the right.
Saturn is hidden in the glare of the Sun.
Uranus (magnitude 5.7, in Aquarius) and Neptune (magnitude 7.8, in Capricornus) are well up in the southeast by late evening. Uranus is currently in the same telescopic field of view with Phi Aquarii, magnitude 4.2.
Pluto (magnitude 13.9, in the northwestern corner of Sagittarius) is highest in the south as soon as it gets dark, about 18° east-northeast of Jupiter. Finder charts for Uranus, Neptune, and Pluto are in the July Sky & Telescope, page 60.
All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's midnorthern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America. Eastern Daylight Time (EDT) equals Universal Time (UT, UTC, or GMT) minus 4 hours.
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