Catalina is a surprise object in the sky. It is rising in the morning near Arcturus on the 1st of January for us to see. The comet passes closest to Earth on January 12th, passing Mizar in the Big Dipper’s handle on January 14–15.
This is a fine binocular or telescope comet topping out at just above naked eye visibility, going into early 2016.
Catalina is coming from very deep space, probably out in the Oort cloud, far beyond the orbit of Pluto.
Now is the time to find it, and it is about 5th magnitude.