Ireland Meteor 28NOV2010 Updated Report and Analysis Meteor/Meteorite News 5DEC2010

Ireland Meteor 28NOV2010 Updated Report and Analysis
  Alastair McBeath has compiled the following report on the 2010 November 28th 17:42 UT (+/- 5 minute) fireball and subsequent reports that evening.

  Using the Armagh data as well as material submitted directly to the Meteor Section, and discounting duplicates, at least 46 separate reports were received of this meteor. Three more sightings may have been of this event too, but contained too few details to be certain. Two others from the Armagh list's reports were of another very bright fireball around 20:00 UT, seen from Counties Armagh and Derry in Northern Ireland, with a further fireball, of about mag -3 spotted by a lone witness in Hampshire at 22:26 UT that evening.

The witnesses for the main event were widely-spread across the western British Isles, with most concentrated in Northern Ireland, but there were plenty more in Eire, Wales and northwest England too, west as far as Bolton in Lancashire and Shrewsbury in Shropshire. Best estimates suggest the fireball happened within five minutes of 17:42 UT, and it probably peaked in the magnitude range -9 to -14 or so.

I've carried out a more detailed review of the available observations in the last few days, though regrettably, it wasn't possible to significantly improve the initially quite vague ideas of where the meteor may have overflown, as the data did not produce a clear, single solution. It seems likely this was because very few people saw either the start or end of the complete trail (fourteen reports specifically mentioned the end as happening behind clouds, trees or rooftops), and the fact the atmospheric trajectory seemed to have been unusually long, and long-lasting.

As a best-guess though, the meteor may have first become visible somewhere high above central to NE Scotland, or over the North Sea off the Scottish east coast perhaps between St Abb's Head and Aberdeen. Its visible end-point was probably over the Atlantic some distance off the Co. Mayo, Eire, coast west of Donegal Bay, or possibly further south. It is likely the only land the fireball flew over was central or northern Scotland and perhaps some of the Western Isles. This could imply an atmospheric trajectory in excess of 600-650 km, if correct.

An unexpectedly large range of visible flight-time estimates was made - between 1.5 to 2 seconds at the shortest to 30 seconds at the longest! This scatter was another factor in suggesting few people apparently saw the whole flight. Most estimates (74%) ranged from 3-15 seconds, with more than half (52%) favouring 5-10 seconds. However, 18% of the estimates still fell between 15-30 seconds. Assuming the long atmospheric path was right could have suggested timings in excess of 10 seconds may indeed have been more accurate. Even a meteor near the upper end of the usual 11-72 km/sec trajectory range for meteoric atmospheric-entry velocities, would have
needed 8 to 9 seconds to accomplish a ~600-650 km flight, for instance.

The fireball was commonly described as quite comet-like, with a distinct, round head and a narrower following tail. Another large scatter was apparent in the colours described as seen in this main meteor and its tail. The percentages of each colour-class from those who mentioned colours at all were as follows. Head or whole fireball: White 28%, orange 20%, green 18%, yellow 15%, blue 15%, red 8%. Tail: Red 28%, white, orange and green 17% each, yellow 11%, blue and purple/violet 5% each.

Sixteen reports mentioned some kind of fragmentation occurred, probably quite late in the flight, with many favouring quite small pieces being involved, often like sparks. However, two people who claimed to have followed the meteor to its end were equally clear that no fragmentation had happened at all. For once, there was consistency in that nobody reported hearing any sounds they associated with the meteor.

Any further sightings of this or other fireballs remain most welcome, and I'd certainly reiterate the call for any CCTV security camera images of the ~17:42 UT event on November 28, which was made earlier by the Armagh analysts.

More here:

http://www.popastro.com/phpBB2/viewtopic.php?t=14866&sid=ee06f7c7a40a1fb86618c0a6e495c59d

Alastair McBeath, Meteor Director, 

Society for Popular Astronomy.
Meteor homepage: http://www.popastro.com/sections/meteor.htm

-- 
Reported by David Entwistle


Comment from Reader:
Michelle McCole wrote: Myself and my partner spotted what we thought was a plane crash landing but then realised we had maybe witnessed a meteor.we were in farnworth,greater manchester and it was roughly 5.45pm on 28th nov.it looked like a bright white star with an orange flame trailing.