The most important factor in these sightings was the weather; prolonged and extensive temperature inversions prevailed in the area all that week. From southern Oregon through northern California multiple inversions of 3 to 18 degrees occurred nightly. Under these conditions, practically any light shining into the night was apt to be projected upward as a mirage and to perform weird antics. Determining what was the particular light source of some specific phenomenon is almost impossible. As complicating factors, certain heavenly bodies made their own contribution to the excitement. Most of the objects observed late at night and watched for periods of one to three hours were refracted images of the stars Capella or Aldebaran or the planet Mars. Some of the most spectacular sightings were those reported from Red Bluff on the night of August 13–14. Two highway patrolmen were chasing a speeding motorcycle when, at about 11:50 P.M. P.D.S.T., they saw what they at first supposed to be a brilliantly lighted aircraft falling directly toward them. Jumping out of their car, they watched the object as it apparently reversed its course, shot upward, and began to perform fantastic maneuvers in the eastern sky. The performance continued for more than two hours. Before it ended, a second UFO had joined in the celestial dance, which was observed by dozens of excited witnesses in the Red Bluff area. Air Force bases in the neighborhood were notified, and ATIC investigators gathered and studied the evidence. There was no real mystery[XII-1]. The UFO first noticed by the patrolmen was probably the star Capella, which at Red Bluff is circumpolar; it rose at 10:50 P.M. and at the time of the sighting was about 4.7 degrees above the northeast horizon. About an hour later (12:48 A.M.) Mars rose, also in the northeast; and close behind it (1:15 A.M.) came the bright star Aldebaran, which made a striking pair with Mars. With three brilliant heavenly bodies just above the horizon, on a night of fantastic multiple inversions of temperature and humidity, the only surprising fact is that the number of UFOs reported was not larger. A person who has never been lucky enough to see a good mirage may feel skeptical about the phenomenon. But those who have encountered a first-rate specimen--for example, the Chicago skyline suspended upside down in mid-air above Lake Michigan--know how startlingly real it can seem. When the source of the mirage is not apparent, the displaced image can seem mysterious and even frightening, as do many UFOs. One such phenomenon, which might easily have been interpreted as a flying saucer, appeared shortly after dark one evening in mid-July, 1954, and was described by Dr. Menzel in a letter to a friend: