Friday, July 28
The weak, long-lasting Southern Delta Aquarid meteor shower is at its maximum activity during early-morning hours for several days around this date.
This evening and for the next couple evenings, you can use your telescope to watch for tiny flashes from Delta Aquarids impacting the dark side of the waxing crescent Moon! For details see the ALPO Lunar Meteoric Impact site.
Saturday, July 29
The red long-period variable star SS Virginis should be at peak brightness (about magnitude 6.8) this week.
Sunday, July 30
At this time of year, the Big Dipper hangs diagonally high in the northwest during evening — with its bent handle pointing left toward Arcturus, which is shining brightly high in the west.
Monday, July 31
Jupiter's moon Io reappears from eclipse out of Jupiter's shadow around 10:35 p.m. EDT, 9:35 p.m. CDT. A small telescope will show it slowly swelling into view just east of the planet.
Tuesday, August 1
Jupiter shines over the first-quarter Moon this evening, as shown above.
Wednesday, August 2
Jupiter shines off to the Moon's upper right in twilight, as shown above, and directly right of it later in the evening.
Jupiter is at quadrature, 90° east of the Sun.
Around 4:20 a.m. Thursday morning Pacific Daylight Time, get a telescope onto Venus very low in the east (if it's up yet for your location). The star Delta Geminorum, magnitude +3.5, will be in the same field of view 10 arcminutes to the planet's south.
Thursday, August 3
The waxing gibbous Moon shines near the head of Scorpius, and to the right of Antares, as shown above.
Friday, August 4
The asteroid 1 Ceres is near opposition, waiting for you to find it with binoculars at magnitude 7.7 just south of Capricornus this week. Use the finder chart in the August Sky & Telescope, page 66. While you're at it, look also for 6 Hebe (magnitude 8.6) and the planet Neptune (magnitude 7.8) just north of Capricornus on the same chart.
Saturday, August 5
Chi Cygni, one of the brightest long-period variable stars, should be nearing its peak brightness (about magnitude 5.2.). It's in the neck of Cygnus, the Swan, near Albireo. Use the comparison-star chart in the August Sky & Telescope, page 67.
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. Or download our free Getting Started in Astronomy flyer (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 beloved if somewhat dated Burnham's Celestial Handbook). And read here how to use them.
For more beginners' tips: "How to Start Right in Astronomy".
This Week's Planet Roundup
Mercury is very dim and very low in the glow of dawn, below bright Venus. Try using binoculars about 45 minutes before sunrise.
Venus (magnitude –3.8, in Gemini) is the "Morning Star" low in the east-northeast during dawn. Much fainter Pollux and Castor are off to its left.
Mars (magnitude +1.8, in Leo) sets in twilight. Using binoculars, you can try looking for it just above the western horizon 30 or 40 minutes after sunset. (Early in the week, you might even pick up Regulus to Mars's lower right.)
Jupiter (magnitude –2.1, in Libra) shines in the southwest as the brightest "star" of evening. The earlier in twilight you look, and the farther south you live, the higher Jupiter will appear in your sky and the sharper the telescopic view will probably be.
At the beginning of this year, Jupiter's "white oval" BA reddened to become "Red Spot Junior"; see our article. Oval BA has just passed Jupiter's Great Red Spot itself. To get all the times when the Great Red Spot crosses Jupiter's central meridian, good worldwide, use our Red Spot calculator.
Saturn is lost in the sunset.
Uranus (magnitude 5.8, in Aquarius) and Neptune (magnitude 7.9, in Capricornus) are well up in the southeast by late evening.
Pluto (magnitude 14, in Serpens Cauda) is high in the south after dark. Finder charts for Uranus, Neptune, and Pluto are in the May Sky & Telescope, page 66.
"Xena," or officially 2003 UB313, (magnitude 19, in Cetus) is in the southeast before dawn. This is the "tenth planet" discovered a year ago, slightly larger than Pluto; see our articles on its discovery and on the finding of its moon. Last October 9th, amateur Keith Murdock of the Rockland (NY) Astronomy Club became the first known human to see the tenth planet visually. He was one of a group of amateurs using the 2.1-meter (82-inch) Otto Struve Telescope at McDonald Observatory in Texas.
The discovery team is informally calling the object and its moon Xena and Gabrielle, for the TV warrior princess and her companion. Official names for them — along with an official ruling on what is a "planet" — may be announced by the International Astronomical Union at its meeting in late August.
All descriptions that relate to your horizon or zenith — 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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