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


Photo of the Week.. A sundog, seen from an aircraft in deep cold at 30,000 feet, is formed by sunlight refracted by ice crystals.

Astronomy news for the week starting Friday, December 31, 2004.

We start with the last night of the year, of 2004; welcome to 2005. To all a Happy New Year to live life and to enjoy the sky.

During the early part of the week the Moon descends through its waning gibbous phase to its third quarter, the phase reached around noon on Monday January 3rd, about the time of moonset in North America. The Moon then takes on the stars and planets. The morning of Monday the 3rd finds the quarter Moon just to the west of Jupiter (which rises just before midnight), which it passes in daylight (even occulting it in parts of the eastern hemisphere) and to the south of Porrima (Gamma Virginis), while the following morning finds the Moon just to the east of the giant planet (and to the north of Virgo's Spica). Then it is Mars's turn, the Moon to the west of the red planet -- and the star Antares in Scorpius -- the morning of Friday the 7th.

Clearly Mars is close to Antares, with which is can be confused since the colors are similar (though Antares is much the brighter). Indeed, "Antares" means "like Ares," Ares the Greek version of Mars. It's a treat to see the two together, Mars just to the north of the star as the year begins. Saturn, which is now a prime evening object that rises in mid-twilight, also gets into the act, passing seven degrees south of Pollux in Gemini on Thursday the 6th (Saturn, Castor, and Pollux making a fine trio), Mars passing north of Antares the following day. The prize for "best relationship" though goes to Venus and Mercury, which as New Year's morning dawns are in tight configuration, Venus just a degree below much fainter Mercury, both down and to the right of Mars and Antares. The twilight morning sky does not get much better.

Early January is host to one of the better meteor showers of the year, the Quadrantids, named after the defunct constellation Quadrans (which is located near the handle of the Big Dipper). The shower will peak the morning of Monday the 3rd near dawn, though its typical rate of up to 100 meteors an hour will be quite restrained by the bright Moon.

Even Earth involves itself in the New Year, as it passes perihelion --its closest point to the Sun -- on New Year's Day, when it is 1.7 percent closer than average, at a distance of 91.4 million miles, or 147 million kilometers. Clearly, given the northern hemisphere's winter chill, the distance to the Sun has nothing to do with the seasons, which are caused by the 23.4 degree tilt of the Earth's axis relative to the orbital perpendicular.

Nothing quite proclaims the New Year and winter like Orion, the celestial representation of the ancient Greek Hunter. Already risen at the end of evening twilight, straddling the celestial equator, Orion crosses the meridian to the south around 11 PM. Among his best features are the first magnitude stars Betelgeuse (at the upper left corner) and Rigel (at lower right), which bracket the famed "Belt," three bright stars that the ancient Arabs called the "String of Pearls."
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