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Venus and Moon

Photo of the Week. The Moon visits Venus in a classic pairing the evening of May 19, 2007.

Astronomy news for the three-week period starting Friday, June 29, 2007.

We begin our three weeks with the full Moon, which takes place the morning of Saturday, June 30. The last full Moon as seen from North America was on May 31, but from Europe, the time was past midnight on June 1. So we have the oddity of a "blue Moon" (second full in the month) in the Old World, but not in the New. After moving through waning gibbous, our companion passes third quarter on Saturday, July 7, wanes through the crescent to new on Saturday the 14th, and, after popping up in the evening western sky, waxes through most of its crescent phase.

As it goes 'round, the Moon passes south of Neptune on Tuesday, July 3, then south of Uranus two days later. The morning of Monday the 9th, the waning crescent can be seen just to the northwest of Mars. As the morning crescent drops toward the dawn horizon it will pass nicely through Taurus the mornings of Wednesday the 11th and Thursday the 12th. The following morning, as the crescent is about to disappear, it will lie just above the dawn horizon and to the left of Mercury. Flipping to the other side of the sky, as the crescent then waxes in the west, you can admire a close encounter with Saturn, the Moon seen just to the left of the planet the evening of Monday the 16th, when the Moon, the ringed planet, Regulus in Leo, and brilliant Venus will all be gathered in a nice clump (Venus and the star a bit farther left). The following night the Moon will appear up and to the left of Venus, the two continuing to make a fine sight.

Three notable events dominate our 1.5-fortnight interval. First, as June turns to July, Venus and Saturn will pass each other by only 0.8 degrees. Formal conjunction takes place the evening of Sunday, July 1. (Venus follows this act by passing south of Leo's Regulus on Monday the 16th.) Second, after growing brighter all year, Venus, coming ever closer to Earth, passes its greatest brilliancy on Thursday the 12th. The night of conjunction with Saturn, it will be an amazingly 120 times brighter than the ringed planet. Finally, on Friday, July 6, Earth takes the stage by passing aphelion, where it is farthest from the Sun in its slightly elliptical path, when it will be 1.7 percent farther than the average of 93.2 million miles.

After admiring Venus and Saturn, turn your eye to Jupiter, which in the middle of our period crosses the meridian around 10:30 PM Daylight Time, about as Saturn and Venus set, the giant planet (just north of Antares) not itself setting until dawn begins to light the sky. In the morning sky, Mars picks up steam by approaching first magnitude and rising ever earlier, shortly after local midnight. Morning's Mercury then hits greatest western elongation just as Skylight's current period draws to a close.

Though large constellations sometimes seem to be the more important, don't forget the smaller ones. Among the best is Lyra. Passing nearly overhead around midnight in the temperate north, marked by bright Vega, it is followed by much larger Cygnus (and Deneb). Just to the south of Cygnus find two of the sky's prettiest smaller figures, Sagitta (the Arrow) and Delphinus (the Dolphin, but shaped more like a hand with a finger pointing to the southwest).
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