Every once in a while, something will appear in the night sky that will attract the attention of even those who normally don’t bother looking up. It’s likely to be that way on Monday evening, Dec. 1.

A slender crescent moon, just 15-percent illuminated, will appear in very close proximity to the two brightest planets in our sky, Venus and Jupiter.

People who are unaware or have no advance notice will almost certainly wonder, as they cast a casual glance toward the moon on that night, what those two "large silvery stars" happen to be?  Sometimes, such an occasion brings with it a sudden spike of phone calls to local planetariums, weather offices and even police precincts.  Not a few of these calls excitedly inquire about "the UFOs" that are hovering in the vicinity of our natural satellite.

Very bright objects

Venus has adorned the southwestern twilight sky since late August.  No other star or planet can come close to matching Venus in brilliance.  During World War II, aircraft spotters sometimes mistook Venus for an enemy airplane.  There were even cases in which Venus drew antiaircraft fire. 

This winter, Venus is the unrivaled evening star that will soar from excellent to magnificent prominence in the southwest at nightfall.  The interval by which it follows the Sun will increase from nearly three hours on Dec. 1 to almost four hours by Jan. 1. It’s probably the first "star" you’ll see coming out after sunset.  In fact, if the air is very clear and the sky a good, deep blue, try looking for Venus shortly before sunset.

Jupiter starts December just above Venus and is moving in the opposite direction, dropping progressively lower each evening.  By month’s end Jupiter meets up with another planet – Mercury – but by then Jupiter is also descending deep into the glow of sunset.  In January, Jupiter will be too close to the Sun to see; it’s in conjunction with the Sun on Jan. 24.

Article Courtsey of Joe Rao Space.com