Skylights featured on Astronomy Picture of the Day

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Skylights featured nine times on Earth Science Picture of the Day: 1 2 3 4 5 6 7 8 9


Photo of the Week. Filtered sunlight. See the rest of the series: 2, 3, and 4.

Astronomy news for the week starting Friday, August 12, 2011.

We begin our week with the Moon in the last stage of its waxing gibbous phase, which ends with full Moon on Saturday, August 13th, during the day with the Moon out of sight. That evening it will thus be barely in the first stage of the waning gibbous, though for all intents it will appear quite full. The next day it will pass several degrees north of Neptune, followed by a Uranian visit on Wednesday the 17th, both passages of no visibility or consequence. The evening of Thursday the 18th, though, is more promising, with the Moon a dozen or so degrees to the west of Jupiter as it prepares to pass north of the planet next Friday night. Fading away during the week in the waning gibbous, the Moon does not pass third quarter until Saturday the 21st. As the week ends, on Thursday the 18th, it goes through apogee where it is farthest from the Earth.

Though technically still with us, Saturn is so far over in the west as the sky darkens that it is effectively gone, setting just half an hour after the end of twilight. Stars and planets become very difficult to see when near the horizon in any case because of increasing obscuration by the Earth's light-absorbing atmosphere. Jupiter, however, is beautifully positioned, rising around 11 PM Daylight Time in south central Aries to the south of the classical figure. It is then with us the rest of the night, not transiting the meridian until sunrise. Mars next enters the scene by rising in the northeast around 2:30 AM beautifully set against the stars of southern Gemini.

Finally, by odd coincidence Venus and Mercury invisibly pass conjunction with the Sun on the same day, on Tuesday the 16th, within 13 hours of each other, but on opposite sides of the Sun. Venus is first, going through superior conjunction (on the other side of the Sun) followed by Mercury passing inferior conjunction (more or less between us and the Sun, though well to the south of the solar disk and not passing across it).

Repeating from last week: The night of August 12 and the morning of the 13th are set for the maximum of the Perseid meteor shower, the meteoroids the flakings of Comet Swift-Tuttle (a small icy body that is slowly dissolving under the action of sunlight), which has a 133-year period, was discovered in 1862, and last came by in 1992. But don't much bother with the shower this year, as the meteors (which through a perspective effect seem to emanate from the constellation Perseus), will be hidden by the light of the nearly-full Moon.

In the early evening after sunset, Scorpius, the celestial Scorpion, dominates the far southern sky. Look then to the north of it for the giant pentagon that makes Ophiuchus, the Serpent Bearer, wrapped by Serpens, the only constellation of the sky that comes in two parts the Head (Serpens Caput) to the west of Ophiuchus and the Tail (Serpens Cauda) to the east.
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