In the past I’ve run a couple of posts about geocaching activities. This guest post by Jen Deyenberg outlined student geocaching activities. Geocaching relies on the use of GPS. On Friday The Atlantic’s Picture of the Day was of the interior of a satellite. That picture as well as thinking about GPS got me to search for a video explanation of how GPS works.

NASA’s eClips channel on YouTube has a good student-friendly explanation of how GPS works.