A fireball over Reading, England

William C. Treurniet, November, 2011

Summary. In July, 2010, four photographs were taken of a fireball passing over Reading, England. The time spanned by the first and last photo was 35 seconds. Analysis showed that the object's speed and brightness changed over the 35 seconds, and that the object was composed of orbs arranged in a triangular pattern. The red and yellow colors of the orbs happen to be the colors of plasmas consisting of nitrogen and oxygen molecules. This suggests that the object was a plasma formed by a moving, localized electrical excitation of the atmosphere at frequencies tuned to the emission spectra of nitrogen and oxygen. The hazy contour around the shape is consistent with this proposal. These observations, combined with previous data, suggest that the object was man-made.

On July 26, 2010, a set of four digital photographs of a ball of fire over Reading, England, were taken with a Sony Ericson C902 cell phone camera by Claire O'Regan. According to the EXIF information, the times when the photos were taken ranged from 22:14:07 to 22:14:42, for a time span of 35 seconds. The photographer estimated that the object moved an angle of approximately 20° during that time. The exposure time for each photo was 1/2 sec, and the image size was 1944x2592 pixels. The original photo taken at 22:14:16 may be seen here for reference.

To compare the interesting parts of the photos, they were first reduced to 1/3 the size, then the object was cropped from each photo. Since some of the streaks in the original images are barely visible, all of the images were enhanced the exact same amount in order to preserve relative brightness. The results are displayed in Figure 1, along with the times when each photo was taken.

  22:14:07 22:14:16 22:14:30 22:14:42
  1 2 3 4
Figure 1. Successive photos of a fireball. 

The second image tells us that the streak is the path of a relatively small, bright, moving object recorded on the camera's sensor during the 1/2 sec exposure time. The start of the streak occurred when the shutter opened. If the streak had actually been in the sky, like a meteor trail, it would have been there before the shutter opened and it would have extended to the edge of the photo.

In the first and third photos, the streaks do start from the edge. To account for this, the object must have entered the camera's field of view during the exposure interval. Since the streak in the first image is longer than in the second image, we can say that the object moved faster in the first image than the second. The distance traveled in the first image was longer and the time of travel was the same or shorter. The streak in the third image is much shorter, so we can not infer anything about it's speed since the object may have entered the field of view at any time during the exposure interval.

We also see that the brightness of the streak varies within and across images. In the first and third images, the brightness is roughly the same. In the second image, however, the object was considerably brighter at one end of the exposure interval than the other. This means that the object increased in brightness during the second exposure interval, but decreased again before the third photo was taken.

The absence of the streak in the fourth image tells us that the object stopped moving during this half-second interval. This offers an opportunity to study it more closely. Figure 2 shows the object cropped from the original photo, accompanied by the same image with dimensions enlarged by a factor of three.

Figure 2. Original and enlarged object. 

The points of light in the lower right corner of the left panel of Figure 2, as well as in the original uncropped photo referenced above, are stars that appear to be in focus. Since the object was high in the sky, it would also have been in focus. Therefore, a poor focus cannot account for the slight haze around the enlarged object. The points of light representing the stars also indicate that the camera was motionless during the relatively long exposure interval. Since the complex shape of the object cannot be attributed to blur from small camera movements, it appears that it is composed of three connected orbs. The color of the object varies from red to yellow.


From the above analysis, we can conclude that the object in the photos varied in both speed and brightness. Further, it was composed of orbs arranged in a triangular pattern. The colors of the orbs were red and yellow, and the overall shape seemed to have a hazy contour. Interestingly, a plasma consisting of excited nitrogen emits light in the red-yellow part of the spectrum, while an oxygen plasma emits a pale yellow color (e.g., here). These two gases are the most abundant in the atmosphere by volume (e.g., here). This suggests the hypothesis that the object was formed by a moving, localized electrical excitation of the atmosphere tuned to the emission lines of nitrogen and oxygen.

The hypothesis offers a possible reason for the observed changes in brightness of the object. Figure 3 gives an enlarged and rotated view of the object cropped from the second image. The left side of the object is a relatively dim red color, but towards the right it becomes yellower and brighter. This correlated change in brightness and color suggests that the brightness is a function of how much ionized oxygen is included in the plasma.

Figure 3. Enlarged crop of the second image. 

A triangular pattern of white orbs was observed in a recent daytime video taken in approximately the same location as the present photos. The article discussing this video concludes that the orbs are likely man-made plasma balls generated from a ground-based apparatus. Perhaps the object in these photos was generated in a similar way. If so, it seems that the color of the plasma can be controlled as well, perhaps by tuning the excitation frequencies so that one or more spectral lines are emitted. Further, the excitation frequencies may also control brightness by selecting which gas is excited.