The people on Project Sign worked fast on the Mantell Incident.
Contemplating a flood of queries from the press as soon as they heard
about the crash, they realized that they had to get a quick answer.
Venus had been the target of a chase by an Air Force F-51 several
weeks before and there were similarities between this sighting and
the Mantell Incident. So almost before the rescue crews had reached
the crash, the word "Venus" went out. This satisfied the editors, and
so it stood for about a year; Mantell had unfortunately been killed
trying to reach the planet Venus.

To the press, the nonchalant, offhand manner with which the sighting
was written off by the Air Force public relations officer showed
great confidence in the conclusion, Venus, but behind the barbed-wire
fence that encircled ATIC the nonchalant attitude didn't exist among
the intelligence analysts. One man had already left for Louisville
and the rest were doing some tall speculating. The story about the
tower-to-air talk. "It looks metallic and it's tremendous in size,"
spread fast. Rumor had it that the tower had carried on a running
conversation with the pilots and that there was more information than
was so far known. Rumor also had it that this conversation had been
recorded. Unfortunately neither of these rumors was true.

Over a period of several weeks the file on the Mantell Incident grew
in size until it was the most thoroughly investigated sighting of
that time, at least the file was the thickest.

About a year later the Air Force released its official report on the
incident. To use a trite term, it was a masterpiece in the art of
"weasel wording." It said that the UFO might have been Venus or it
could have been a balloon. Maybe two balloons. It probably was Venus