(meteorobs) mpg of a 15s fireball from last April

[esko.lyytinen at jippii.fi]

Hi Ed and Ykchia,

This fireball was quite thoroughly analyzed. It moved (in apparent 
speed) very slowly at the beginning because of longish distance and 
coming roughly towards the observing-station.

Assuming a starting height of 82 km/s, the entry velocity would have 
been about 12.5 km/s. So at orbiting satellite heights the speed would 
have bee consequently even a lot bigger and it coud not have been in 
Sun-light. End height of about 50km:s was derived with the above start 
height assumption.

So it defnitely could not be an orbiting satellite and not even decaying 
space debris. It was not as easy to be sure that it was not an airplane. 
An aiplane would have needed (to fit the observations) to go at too low 
an altitude above the city (but not by a very definite margin).
This (not an air-plane) was made certain by the two visual sightings at 
locations that were situatde by about 200 km:s from here and more than 
100km:s from each other (I recall).

I tried a deceleration analysis and dynamic mass determination. 
According to this, a small piece of maybe 5 grams could have survived, 
but because of only a one station determination, the mass-value is more 
than an order of magnitude uncertain.

Esko

>> Hi Esko:
>>
>> Finally got the IE to download the file and view it. (Won't work in
>> my netscape). Very interesting movie indeed.
>> I could not see the 'tail' in real time playback (may be the
>> fisheye did not show the dim tail). Could this be an iridium satellite
>> flare?
>>
>> rgds
>> ykchia
>>
>I have looked at your video and I do not think it is an iridium
>satellite flare. I have recorded many flares with a Sandia Convex all-sky
>camera and they are just a single flash of light. A Sandia all-sky records
>meteors of around -3 magnitude and brighter so tails are not recorded. Your
>fisheye unit might be more sensitive but I don't expect by much so you will
>not record the persistent trail of a fireball unless it is extremely bright.
>It looks like you have just recorded a bright meteor fireball.
>
>
>Ed Majden
>West Coast Sandia Bolide Detection Station
>Courtenay B.C. CANADA