From the document: "Recently, many credible witnesses, often military aviators, have reported seeing objects they did not recognize over U.S. airspace. Most of these events have since been explained, but a small handful cannot be immediately identified as known human-made or natural phenomena. These events are now collectively referred to as Unidentified Anomalous Phenomena, or UAP [Unidentified Anomalous Phenomena]. A vital part of NASA's mission is exploring the unknown using the rigorous process of the scientific method. This means scrutinizing our assumptions and intuition; transparently and diligently collecting data; reproducing results; seeking independent evaluation; and finally, reaching a scientific consensus about the nature of an occurrence. The scientific method challenges us to solve problems by impartially evaluating our own ideas, by being willing to be wrong, and by following the data. [...] This report offers a vision of how NASA could contribute to understanding the phenomena and how the agency's approach will complement the whole-of-government effort to understand UAP."