Skylights featured on Astronomy Picture of the Day

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Tropical Sunset

Photo of the Week. Tropical Sunset.

Astronomy news for the three weeks starting Friday, January 1, 2010.

Welcome to the New Year, and may it be a good one for you. We finally made it out of the "zeros." The next Skylights will appear Friday, January 22, 2010.

There is a lot to report on. First up, the Moon. With full phase having taken place on New Year's Eve, during our extended period the Moon goes through almost three fourths of its phase cycle, beginning with the waning gibbous. It then passes through third quarter on Thursday, January 7, whereupon it enters the waning crescent as it heads towards new Moon on the night of Thursday the 14th. Your last look at the slim waning crescent can be had in eastern twilight the morning of Wednesday the 13th, while you might get your first look at the narrow waxing crescent the western twilit evening of Saturday the 16th. We then head toward first quarter, which will not take place until Saturday the 23rd.

This new Moon will eclipse the Sun, though not for North America. It will instead be widely seen along a path through Africa and Asia, the partial eclipse viewable across both continents and parts of Europe. Unfortunately, with the Moon passing apogee a day after new phase, where it is farthest from Earth, it cannot quite cover the Sun, resulting in an "annular eclipse" in which a ring of sunlight surrounds the darkened Moon.

Given three weeks of movement, the Moon will encounter several stars and planets, beginning with Mars. Look for it rising to the right of the red planet in mid-evening the night of Saturday the 2nd, with the Sickle of Leo down and to the left. The following night, the Moon will appear directly south of Regulus. Saturn gets passed during the day of Wednesday the 6th, so the Moon will appear to the west of the planet that morning, to the east of it the following morning, falling more or less between it and Virgo's Spica. The Moon then glides immediately to the left of Antares the morning of Monday the 11th. The very thin crescent will thence appear down and to the right of Mercury the morning of Wednesday the 13th. As it grows, the waxing crescent will make a nice sight with Jupiter, appearing down and to the right of it the evening of Sunday the 17th, above it the following evening. Neptune and Uranus respectively get passed on Sunday the 17th and Wednesday the 20th.

As to the planets unto themselves, Mercury passes inferior conjunction with the Sun (between it and us) on Monday the 4th, then appears nicely in the morning sky toward the end of our triple-week. Venus, on the other hand, does the opposite by going through superior conjunction, on the other side of the Sun, on Monday the 11th. The next-to-biggest planetary news is Saturn's entry into retrograde motion on Thursday the 14th, when it turns around in western Virgo and starts heading westerly against the stellar background. Rising ever earlier, the ringed planet is up by 11-11:30 PM. The early evening, however, belongs first to Jupiter, which now sets by around 8 PM, and Mars, which rises on the Leo-Cancer border about the end of evening twilight.

The biggest planetary news, though, involves Earth, which passes perihelion, where it is closest to the Sun (91.4 million miles, 147.1 million km, 1.7 percent closer than average), on Saturday the 2nd. That, combined with near-full Moon and the Moon near perigee on New Years' Day, will make for especially high and low tides as 2009 goes into 2010.

The morning of Sunday the 3rd marks the peak of the Quadrantid meteor shower. One of the best of the year, the leavings of a broken comet listed as an asteroid, the Quadrantids arise from a defunct constellation (Quadrans, the Quadrant) near the Big Dipper. Unfortunately, the bright Moon will pretty much wipe them out.

It's mid-season for the winter constellations, among which Taurus, the ancient Zodiacal Bull, stands out for its first magnitude star Aldebaran and its two naked-eye clusters, the Hyades that seem to surround Aldebaran, and the more compact Pleiades, all above and to the right of mighty Orion.
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