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Photo of the Week. Rays of sunlight with dark cloud shadows delight the summer eye.

Astronomy news for the week starting Friday, August 1, 2008.

We are in currently an interesting (though short) time in which the lunar phases are synchronized with Skylights' week, with particular phases of the moment taking place on Fridays: last full Moon occurred on July 18, last third quarter July 25, new Moon (and eclipse in Eurasia) Friday, August 1, and continuing on to first quarter on Friday, August 8. This week will thus be spent on the waxing crescent. With a good clear horizon, you might see the first appearance of the slim crescent the evening of Saturday, August 2, in bright western twilight. Look then to the right parallel to the horizon and see if you can spot bright Venus, which is starting to climb out of the murk. (Regulus will be between the two, but near-impossible to see.)

Above the slim crescent will be much dimmer Saturn (the Moon passing four degrees south of the Saturn during the day on Sunday the 3rd). The Moon will be much more easily visible that evening, when it will be directly to the left of Saturn and below Mars, these two planets now quite difficult to spot. In the continued interplay of planets and stars, Venus passes 1.1 degrees north of Regulus in Leo on Tuesday the 5th.

These elusive three planets are all now set in twilight. Jupiter is just the opposite, not just in position, but observationally as well. Still moving retrograde (westerly) above and a bit east of the Little Milk Dipper of Sagittarius, the brilliant giant of the Solar System is beautifully visible in the southeast at twilight's end. Crossing the meridian to the far south around 11 PM Daylight Time, Jupiter does not set in the southwest until just before twilight begins to brighten the morning sky.

In its waxing crescent phase, especially in the early part of the week, the Moon is not bright enough to bother the stars very much. The first order of business is to admire bright Vega (of Lyra, the Harp), which for mid-northern latitudes is almost overhead at 11 PM, about the time Jupiter transits as well. Hercules will be to the west, Cygnus (the Swan, with its Northern Cross and the bright star Deneb) to the east. Due south of Cygnus are a pair of small, exquisite figures, hand-shaped Delphinus (the Dolphin) and Sagitta (the arrow), both of which are nicely shown in the background of the film WALL-E. Far south of Vega, near the horizon, we return to Sagittarius and its stunning neighbor to the west, Scorpius, both constellations holding the brightest parts of the Milky Way.
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