Santa Claus is in Europe, tracking on time toward the United States, according to the latest report from NORAD Santa Tracker 2011 via Google Earth.

At just before six p.m. Eastern Time, Santa had visited more than 1.1 billion homes around the world and had just left Slovakia heading for Austria. By the end of his trip, Santa will visit more than three billion homes in the world, arriving in the U.S. in the overnight hours.

That's good news for children in the U.S. and Canada, as Santa appeared on schedule, according to the Google Earth and NORAD Santa Tracker 2011.

Santa got underway on his journey around the world early on Christmas Eve. By 9 a.m. Eastern Time on Saturday, NORAD had Santa at Canberra, Australia, heading for Hobart Tasmania before making his way tonight to the United States.

For five decades, NORAD and the Continental Air Defense Command (CONAD) have tracked Santa's flight, beginning precisely when Christmas Eve begins.

At 12 a.m. on Dec. 24, you can click on this link and track Santa's journey on the NORAD Santa Tracker 2011. You can also see a video below featuring Santa's tracks from NORAD Santa Tracker 2010.

According to NORAD, the tradition began in 1955 after a Colorado Springs-based Sears Roebuck & Co. advertisement for children to call Santa misprinted the telephone number. Instead of reaching Santa, the phone number put kids through to the CONAD Commander-in-Chief's operations hotline. The Director of Operations at the time, Colonel Harry Shoup, had his staff check the radar for indications of Santa making his way south from the North Pole. Children who called were given updates on his location, and a tradition was born.

It was 1958 when the governments of Canada and the U.S. created NORAD, and at that time the new command tackled the tradition of tracking Santa each Christmas.

Since that time, the agency says, NORAD men, women, family and friends have selflessly volunteered their time to personally respond to phone calls and emails from children all around the world. In addition, we now track Santa using the Internet. Millions of people who want to know Santa's whereabouts now visit the NORAD Tracks Santa website.