Four
planets shine in the western twilight. One dazzles; the others appear
tiny by comparison. Watch them changing positions day by day! (The
visibility of faint objects in bright twilight is exaggerated here.)
Friday, July 30
As twilight fades, how soon can
you spot bright Venus in the west? How soon after that can you spot
Saturn and Mars, much fainter, to Venus's upper right? This evening Mars
is less than 2° below Saturn. Use binoculars to try for Mercury and
fainter Regulus much farther to Venus's lower right.
Around 11 p.m. daylight-saving time, Jupiter rises roughly 6° lower
right of the waning Moon (for skywatchers in North America).
Saturday, July 31
Saturn and Mars remain close together upper left of Venus at dusk, as shown above.
Sunday, August 1
Bright Vega crosses
nearest your zenith around 11 p.m. daylight-saving time, depending on
how far east or west you live in your time zone. Whenever Vega is
nearest the zenith, you can count on the Teapot of Sagittarius, rich in
deep-sky objects, to be at its highest in the south.
Monday, August 2
Last-quarter Moon tonight (exact at 12:59 a.m. Tuesday morning EDT).
Tuesday, August 3
Look east before dawn for the Pleiades 3° or 4° lower left of the waning Moon (as seen from North America).
Wednesday, August 4
Vega and Lyra shine
very high during evening for observers at mid-northern latitudes. Do you
know Lyra's two Messier objects? The Ring Nebula, M57, is familiar and
easy to find. But what about the globular cluster M56? See Gary
Seronik's Binocular Highlight article and chart in the August Sky & Telescope, page 45.
Thursday, August 5
No less than eight
globular clusters pepper the area around the spout of the Sagittarius
Teapot. Ferret them out with your telescope these evenings using Sue
French's Deep-Sky Wonders column and chart in the August Sky & Telescope, page 64.
Friday, August 6
Starting this evening,
Mars and Saturn spend more than a week sliding just above brilliant
Venus low in the west as twilight fades.
Saturday, August 7
Venus, Mars, and Saturn
are gathered most tightly this evening, fitting in a circle 4.8— in
diameter — just small enough to qualify as a "planetary trio," a
grouping within a 5° circle.
Venus remains the bright landlark for shy Mars and Saturn after sunset.
Sunday, Aug. 8
Watch the Venus-Saturn-Mars
triangle as it changes shape day by day in the western twilight. Spica
too is now moving in on the scene from the left, as shown here. Can you
also make out Gamma Virginis, magnitude 2.7? For this one you'll
probably need binoculars.
Have you seen any early
Perseid meteors yet? The peak of the annual shower is expected to arrive
next Thursday night, the night of August 12-13. Start planning now! See
our article Dark Nights for the Perseids.
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