Skylights featured on Astronomy Picture of the Day

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Skylights featured three times on Earth Science Picture of the Day: 1 , 2 , 3 , 4 .

Lunar corona

Photo of the Week.. A spectacular diffraction corona surrounds the Moon, caused by diffraction of moonlight through light clouds, the same phenomenon that makes the colors in a compact disk.

Astronomy news for the week starting Friday, February 4, 2005.

A belated Happy Groundhog Day (February 2) to everyone. An astronomical "holiday," Groundhog Day is one of the four "cross-quarter days" that split the differences between the passages of the Sun over the equinoxes and the solstices. We are halfway to spring (in the northern hemisphere).

We start the week with the waning crescent Moon in the morning sky, as it goes toward its new phase, with the Moon between us and the Sun, on Tuesday, February 8. By the night of Wednesday the 9th, if you are lucky you might get to see the very thin waxing crescent in the southwestern evening twilight sky. By the night of Thursday the 10th, you will not have to look as such, as the Moon -- in twilight -- will be pretty obvious. Then, and over the following few nights, it will present a beautiful sight, as its nighttime side will be aglow with Earthlight, with light reflected from (from the point of view of the Moon) the nearly-full Earth. Almost exactly one day before the Moon passes new, on Monday the 7th, it runs through perigee , which will make for nicely high (and especially low) tides at the coasts (not an issue in the Midwest).

The morning of Friday the 4th the waning crescent was just to the east of Antares in Scorpius. The following morning, that of Saturday the 5th, the even thinner Moon will pass four degrees south of Mars, which is now to the northwest of Sagittarius. Mars, however, pales next to Jupiter, which dominates the morning sky, the planet now in retrograde and up and to the right of Spica in Virgo. Ever so slowly the giant planet is moving into the evening sky. Now rising around 10:30 PM, it is rather well to the west of the meridian as dawn lights the morning. Jupiter and its brother planet Saturn -- the two of similar size and construction -- are working in a sort of synchrony. Saturn now rises well before sunset and is nicely up in the northeast as twilight darkens the sky, and for the next month or so, it crosses the meridian just as Jupiter rises.

Watch Auriga, the ancient Charioteer, cross the sky nearly overhead in mid-northern latitudes. The constellation, halfway around the pole between the Big Dipper and Cassiopeia, is one of the most prominent of northern constellations, its luminary Capella the most northerly of first magnitude stars. Plunge southward and you pass through Taurus (with bright Aldebaran), Orion (with Betelgeuse and Rigel), Lepus (the Hare), and Columba (the Dove). Auriga's positional counterparts in the deep southern hemisphere, far to the south of Orion, are (roughly) Pictor, the Easel, and Dorado, the Swordfish, modern constellations that are much too far south to be seen from ancient northern lands. Dorado contains one of the most remarkable objects of the sky, the Large Magellanic Cloud, a nearby satellite galaxy 150,000 light years away.
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