Unidentified anomalous phenomena

What the term means

NASA uses unidentified anomalous phenomena as the expansion of UAP. Observations can be difficult to assess when the available sensor data, calibration or environmental context are limited.

How to evaluate a case

Separate a witness account, an authentic recording and an inference about the object. Better sensor calibration, multiple observations and transparent analysis can narrow possible explanations. NASA’s 2023 study concerns methods and data, rather than a verdict on every past incident.

Source chronology

Dates below describe source publication, which may differ from the date of an observation or event.

Connected knowledge

Source trail

Use the Primary sources tab to inspect the original records, publication dates and provenance.