See the 5-day-old crescent moon have a holiday meet-up with Saturn tonight

A large orange circle that spans the height of the image includes saturn and the moon.

The moon will meet up with Saturn, the solar system's second-largest planet, on Sunday (Dec. 17) when the two celestial bodies make a close approach. 

The moon will be almost half-illuminated during the close approach, and at around the same time, the two celestial bodies will share the same right ascension (the celestial equivalent of longitude) in an arrangement astronomers call a conjunction.