Wondering how come it's 10:10pm, the sky appears to be clear tonite: i can see plenty of stars but i cant see the moon?? its not where it usually is??
Posted March 4, 2008
MIKE MOSS SAYS: Jim, Because the moon has an orbit around the earth that is tilted with respect to the earth's equatorial plain and is not an even multiple of the daily rotation period of the earth, it does not really have a "usual" position at a given time each nite, but varies in a predictable manner, and of course is not visible at some times of nite or during some entire nights near the "new" moon phase. The U.S. naval Observatory makes it easy to calculate the expected position of the moon at any given time using the online calculator at this address:
In particular, see the tools under the "Positions of Selected Celestial Objects" heading.