An e-UFO sighting over Reading, England

On May 23, 2010, at 8:03 PM, Claire O'Regan of Reading, England, recorded the following video of a strange object as it passed quickly overhead near her home. The object appeared to have the shape of a lower-case 'e'; hence, the name e-UFO. The video is about one minute in duration, but the object is seen mainly in the first 12 seconds with the optical zoom. The remaining time was spent searching for the object without the zoom after it was lost from the viewfinder. It was found very briefly at 19 sec and again at 45 sec.

The object appeared to be at quite a high altitude and rotated slowly as it traveled horizontally in the eastward direction. The object had a shiny, gray metallic appearance, and appeared to emit flashes of colored light. The sky was clear and the sun was above the horizon just before setting. Recording of the video began when the object was approximately overhead.

Figure 1 shows the various shapes of the object as it rotated through the sky over a period of roughly nine seconds. The views are arranged in order of appearance in successive rows from top to bottom.

Figure 1. Different perspectives of rotating object

All views are consistent with the changing orientation of a rigid object shaped somewhat like the letter 'e'. The object is a dull gray in color, with specific areas that seem to be highly reflective. The reflected colors are white, green, yellow, and red, suggesting that parts of the object were covered with a thin film of transparent material. The film would cause destructive interference of the sunlight as it was reflected back to the camera, and the wavelength or color of the light that was reflected would depend on the thickness of the film (Jenkins and White, 1957, p. 261).

A possible explanation of the sighting is that the object was some kind of unusual balloon. Are the observed conditions consistent with this explanation? The photographer reported that the object moved silently from west to east at a constant height. Although difficult to see with the unaided eye, the object was spinning at a slow pace compared to its forward movement. When it was overhead, it appeared to be moving more slowly than later when it seemed to speed up before it quickly vanished. The final speed seemed faster than that of an airplane.

From information available at the Weather Underground, we know that the wind speed around 8:00 PM on that day was 16.7 km/hr and the direction was from the south-west. Such a gentle breeze is consistent with the photographer's impression that "the birds were singing and everything was quite still. It was one of those relaxing summer evenings - it was peaceful".

Figure 2. A video frame showing the object relative to a tree branch.

At the beginning of the recording, the object is almost directly overhead. Forty-five seconds later, the object is again briefly visible some distance away as a very small dot. Figure 2 shows that instant in the video, with the object above a line drawn even with a tree branch at the left edge of the image.

Figure 3. Geometric relationships for calculating altitude.

With the help of Figure 2 and the additional measurements by the photographer shown in Figure 3, we can measure the object's altitude and judge whether or not it could reasonably have been a balloon traveling at the wind speed of 16.7 km/hr. The distance covered in 45 sec would have been 0.21 km. Figure 3 shows that the tree branch was 6 ft above the ground, the camera position was 11 ft from the tree, and the camera height was 5.5 ft above the ground. A line drawn from the object to the camera would pass roughly 2 ft above the level of the tree branch shown in Figure 2. Angles A and B are easily calculated and lead directly to calculation of the altitude of the presumed balloon.

It is evident in the video that the object is rotating at roughly one revolution every three seconds. A balloon could sustain such angular momentum only if it were under high pressure and continuously leaking gas. Obviously, this could not be maintained for long without an additional onboard source of energy.

Further, the wind was from the south-west at the time, and the witness insists that the object was definitely moving due east as measured with her iPhone compass. Thus, the altitude calculation, the observed rotation, and the known wind direction are all inconsistent with the balloon hypothesis.

Is it possible to estimate the object's size? This is difficult to do since there is usually no familiar frame of reference in the sky. Nevertheless, the witness to this sighting had a strong impression that the object was at or above the altitude of aircraft bound for Heathrow airport 40 km away. According to expert opinion, a typical aircraft altitude over populated areas well before landing would be around 20,000 ft. We will use this altitude in calculations to estimate the object's size.

The size of the recorded object at any altitude can be estimated from its size in the video image if we know the angle subtended by a recorded scene at the camera lens. At the beginning of the video, the object was recorded with no zoom. From measurements provided by the photographer, the whole image width without optical zoom subtends an angle of 52°. By comparing it to the whole image width, the object's width appears to subtend 0.226°. The object at 20,000 ft would then have a width of about 79 ft.

A difficulty with deriving this estimate was that the object without optical zoom is very small, and its width in the image was difficult to measure accurately. It would be preferable to use the larger magnified object seen later in the video. Therefore, the angle subtended at the lens at maximum zoom was also measured. The whole image width in this case subtended only 1.823° and the width of the object itself subtended 0.3012°. For an altitude of 20,000 ft, this translates to a physical size of 105 ft for the object sample seen at 5 sec into the video (i.e., the upper-right image in Figure 1).

If the constraint on the object's speed is removed, the geometrical relationships derived from Figure 3 can also give an estimate of the distance and speed of the object at any given altitude.

Therefore, if it were at 20,000 ft, the object would have covered a distance of 26.84 km in 45 sec at a speed of 2147 km/hr.

Some could reasonably argue that it is impossible to judge the height of an unknown object by comparing it to the altitude of passing aircraft, so a size estimate using this altitude is not reliable. But stereo depth perception operates up to roughly 2000 ft, so if the witness overestimated the altitude of the object, it was likely still greater than 2000 ft. At this height, the object would have traveled 2.68 km at a speed of 215 km/hr, and would have been roughly 10 feet wide.

The similar Anthony Woods sighting

In the spring of 2002, Anthony Woods filmed a very similar object near his home in Portsmouth, England, less than 100 km from Reading. This sighting was included in a documentary produced by UFO Magazine, which discusses some of the more than 100 hours of mostly daytime UFO sightings recorded on video by Woods.

Figure 4. Two perspectives of Anthony Woods' object

Figure 4 shows two perspectives of the object recorded by Woods. Additional perspectives can be seen in a review article by James Neff showing many more images of this object. Like the Reading object, this object can also be characterized as having the shape of the letter 'e'. It slowly changed orientation as well, and occasionally flashed an intense reddish light. According to the UFO Magazine documentary, the object's shape appeared to be twisted so that there was no line of symmetry. Further, some of the light flashes from the object might have been reflections of an external source, while others seemed to have been internally generated. The documentary concludes that the appearance and movement characteristics of the object were inconsistent with a known object such as a balloon.

Conclusions

The first impression from viewing the video is that the object could be an oddly shaped balloon pushed along by the wind. Calculations based on this assumption gave an altitude estimate of 162 ft that was unacceptably low according to the witness. Further, the wind direction at that time was not consistent with the measured direction of the object's movement, and the observed angular momentum could not have been maintained for long without an additional onboard source of of energy. Therefore, the assumption that it was a balloon is not supported.

It should be noted that an inexpensive balloon in the shape of a numeral '6' can be purchased for use with helium. This particular balloon is about 3 ft in length, and calculations show that it would be the size that was photographed if it were at an altitude of 570 ft. This is about 3-4 times higher than expected if it were being pushed only by the wind. An object at this distance would have a stereo angular disparity of 71 arc seconds which is within the usable range for normal stereo depth perception. Stereoscopic vision can operate at distances up to at least 2000 ft, so when the witness observed that the object flew at the level of aircraft at 20,000 ft, we should accept that it was well above 570 ft. Further, it is not clear why such a party balloon exposed to sunlight would reflect the rainbow colors that are evident in Figure 1.

The witness surmised that the altitude of the object was roughly equivalent to that of aircraft often seen flying overhead on the way to nearby Heathrow airport. Such altitudes are typically around 20,000 ft. A balloon drifting at an altitude of 162 ft is unlikely to be confused with a much larger object at 20,000 ft. Using known properties of the camera, the object's width at that assumed altitude was estimated to be about 100 feet.

Bibliography

Jenkins, F.A. and H.E. White, Fundamentals of Optics, McGraw-Hill, New York, 1957.

Index