NORAD has confirmed that Santa and his sleigh took off from the North Pole at 6 a.m. EST today. NORAD says its "radar is tracking Rudolph's bright red nose, and satellite imagery is providing minute-by-minute coverage of Santa's location."
See Santa's progress across the globe
NORAD's tradition of tracking Santa started in 1955 in Colorado Springs. A Sears & Roebucks store in that city printed an ad encouraging children to call Santa - but the phone number was wrong. Very wrong.
The children's calls went to the hotline for the Continental Air Defense's Director of Operations, Col. Harry Shoup. (What was then called CONAD is now NORAD.)
Read about Col. Shoup's reaction to the sudden flood of phone calls.