Look up. That's what a host of people will be doing Dec. 5 as they take on DARPA's challenge to be the first to locate 10 large, red weather balloons and win a $40,000 cash prize.

DARPA, also known as the Defense Advanced Research Projects Agency, issued the DARPA Network Challenge to mark the 40th anniversary of the Internet, which occurred Oct. 29. The agency will position the 10 balloons in undisclosed locations across the continental United States for one day (Dec. 5). The first person to identify the latitude and longitude of all 10 balloons will earn the $40,000 prize.

DARPA describes its Network Challenge as "a competition that will explore the role the Internet and social networking plays in the timely communication, wide area team-building and urgent mobilization required to solve broad scope, time-critical problems." As such, it is open to participants worldwide and of all ages.

According to the defense agency, the moored balloons will be in readily accessible areas and visible from nearby roads.

For additional event details and to register, go online to www.darpa.mil/networkchallenge.