Monday, March 26, 2007

The planet Saturn is presently making one of its retrograde motions and passing from the constellation of Leo westward to the faint constellation of Cancer. It previously passed to Leo from cancer last fall in Sept and Oct.. Looking down the alley from her city location Molly cannot distinguish any of the stars of Cancer, but she can easily make out most of the stars of Leo and at least Castor, Pollux, Tejat and Alhena in Gemini (the constellation immediately to the west of Cancer). Saturn is about 15 degrees to the west of Algiebra(the second star in the "hook" of Leo, and a bit further towards the zenith than the bright star Regulus (the beginning of the "hook"). Viewing is a bit restricted because of the light of the first quarter Moon. Tonight, at about 11:00 pm Central Standard Time, Leo and Saturn are a bit to the east of due south. Orion has begun to advance towards the horizon in the southwest. Sirius, the brightest star in the sky, is almost due south.
For further information on the planet Saturn go to the Wikipedia article and the Nine Planets site. The two sites complement each other.
A little interesting Saturn factoid. The actual length of a Saturnian day is uncertain. The gaseous nature of the planet leaves no firm "handle" to measure the period of rotation. Astronomers have relied on radio measurements of the planet's magnetic field to make their estimates, but recent findings have shown that geyser activity on the small Saturnian moon Encaledus inhibits the rotation of the planet's magnetic field to a speed less than that of the actual rotation. The most recent measurements place Saturn's "day" as about 10 hours and 47 minutes. Interestingly enough comparative measurements have shown that this is about 6 to 8 minutes longer than the time Saturn took to rotate in the 1980s when the first measurements were taken.
Anyways, more on Saturn, Leo and the other constellations mentioned later.

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