Fireball 16th July 2005

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Fireball forward scatter recording from 16th July 2005

I'd welcome comments on the following information, which is speculative. I'd particularly welcome other data and eye witness accounts concerning this event. You can contact me using the feedback page, or using the meteorobs forum.

On the evening of 16th July 2005 there were several reports of an bright fireball seen from Wales, southern England, Guernsey and Belgium. Early indications were that the object travelled from west to east somewhere across southern England, or over the English channel. Reports were consistent reporting the sighting at 20:19. The Sun was still above the horizon for observers in the west of the area covered, suggesting that the event must have been extremely bright.

From my home in Preston, Lancashire I operate a meteor forward scatter system and monitor signals from a TV transmitter in Portugal. The meteor would have travelled through the area of sky that I monitor. Forward scatter measurements have their own difficulties, especially during the summer months, but I believe it unlikely that the results seen are a coincidental. However, there are some interesting differences between the visual reports and the data I collected.

The first chart shows the hourly meteor counts recorded. This shows a sharp peak during the hour from 20:00 UT to 21:00 UT.

The second chart shows the flux recorded by my radio forward scatter system on the 16th July 2005. The flux provides indication of the signal strength received. The large increase shortly after 20:00 may be due to the fireball.

The chart below shows the flux readings for the two hours from 19:00 UT to 21:00UT.

Subsequent investigations showed the monitoring systems clock to be 2 minute 30 seconds fast, suggesting that the measured flux peaked at 20:10 UT.

The counts associated with the event also start to increase at 20:10, but peak around 20:20.

Conclusion

It is noted that the increase in measured signal strength starts at 20:10 UT, which was several minutes before the main visual event at 20:19 UT. It is also noted that the counts continue to increase over a period of tens of minutes and appear to peak shortly after 20:20 UT.

Given these two things, I would suspect that although the visual event was clearly associated with a particularly large body, the whole event may have been prolonged and resulted from a stream of particles impacting the Earth's atmosphere, rather than one single meteoroid. This view may also be supported by the slight increase in counts in the hour preceding the event and the hour after the event.