As darkness is falling Wednesday and Thursday evenings (Jan. 25 and 26), be sure to take a look toward the west-southwest part of the sky for yet another beautiful celestial tableau formed by a lovely crescent moon and the brilliant planet Venus, virtually a repeat of their post-Christmas night get together.
On Wednesday, the moon will be about 9 degrees below and to the right of Venus, while on Thursday night, it will have shifted to a position about 7 degrees above and to Venus' right.
These Venus-moon rendezvous occur on roughly a monthly schedule. Indeed, if Venus were stationary and did not appear to move against the starry background, then a Venus-moon encounter would occur every 27 days, 7 hours and 43 minutes. This is called a "sidereal month," which is the length of time it takes the moon to circle the Earth once, using the background stars as a reference point.
