From the article

>A new paper from the Pentagon’s All-domain Anomaly Resolution Office (AARO) and Harvard University confirms that these UAPs seem to defy physics as they lack certain tell-tale signs, such as an ionized tail or optical fireball produced by friction.

Also from the article

>The research around Unidentified Aerial Phenomena (UAP), which are really just UFOs by another name, is often wrapped up in the feasibility of intelligent life visiting Earth. But in a new draft paper (that has yet to peer reviewed), Sean Kirkpatrick, director of the Pentagon’s All-domain Anomaly Resolution Office (AARO), and Harvard University’s Avi Loeb, stripped away the more philosophical questions about life on other planets and instead focused on the physics of “highly maneuverable” UAPs specifically.
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>While designing “physical constraints” in order to analyze these UFOs, Kirkpatrick and Loeb determined that the recent UAP observations do defy the laws of physics, stating that “the friction of UAP with the surrounding air or water is expected to generate a bright optical fireball, ionization shell and tail—implying radio signatures.” However, many of the UAPs studied show no signs of these signatures