Most UFOs are balloons, misidentified aircraft, secret military aircraft, drones, or weather phenomena. But what happens when a truly unknown UFO, an apparently intelligently controlled machine of exceptionally advanced technology, appears?

That's what at least some in the U.S. government are trying to get to the bottom of. Last week, Congress held the first UFO hearings in 50 years.

Ariel Phenomenon, however, focuses on the more than 60 middle school students who claimed a saucer-shaped UFO landed just beyond their playground at a school near Harare in 1994. This mass sighting has since become part of modern UFO lore. Weaving contemporary interviews of the now-adult students with archive video, Randall Nickerson's work suggests that something did indeed happen on that day in 1994.

The question, of course, is what.

Was it a prank, with influential children guiding their contemporaries in an elaborate hoax? Was it an incident of mass hysteria? Did a helicopter land, and the children decided they had seen a strange UFO? Or did the students actually see a UFO of truly exotic form?

Nickerson believes he himself is a victim of UFO abduction, suggesting as much on The Oprah Winfrey Show. This will lead some to believe that his work is biased to reinforce his own preconceptions of what UFOs might be.