Researchers want to study UFOs. How do they collect good data?

A number of military pilots testified before Congress recently about unexplained objects seen in airspace.

Scientists, including those at NASA, are interested in studying UFOs or, as they're now called, UAPs — unidentified anomalous phenomena. But there's a big challenge; it's difficult to collect the data to draw scientific conclusions.

Alan Yu of WHYY's The Pulse reports.