(meteorobs) Information about observed fireballs

[Meteorites USA]

Chris, I agree with most of what you said, except...

"...Most really spectacular fireballs probably don't produce meteorites..."

In recent months one can look back at Buzzard Coulee. This is a perfect 
example of a spectacular meteorite dropping fireball. West (Ash Creek) 
was a daylight fireball, and visible from over 120 miles away in the 
middle of the clear blue midday sky. If it had been at night I imagine 
that would have been a spectacular fireball as well, lighting up the sky 
and putting on a nice light show. Maybe defining spectacular would be in 
order... ;)

I guess my point is that you are right. We really don't know which 
fireballs drop meteorites and which do short of finding a meteorite 
under their terminal burst point, but chasing them sure is fun! One day 
we'll have better data technology and knowledge and hopefully be able to 
determine based on observation the chances of meteorites from watching a 
fireball event. Kind of like a weatherman gives a 30% chance of 
afternoon showers... ;) Maybe we'll have a fireball man that watches the 
skies and gives the daily fireball weather report.

"Sunny and balmy, winds at 5mph out of the NorthEast, with 100% chance 
of meteorite showers today from asteroid TC3 over Sudan."

Hmmm... Could happen.

;)

Regards,
Eric



Chris Peterson wrote:
> We don't know, unless somebody actually finds a meteorite!
>
> Good indicators are: low initial speed (<30 km/s), shallow entry angle 
> (<45°), a terminal explosion, or possibly intermediate fragmentation events. 
> Of course, the fireball should be sporadic- many impressive meteors are 
> associated with showers, and there's little or no chance of these producing 
> meteorites. A really long ground path is probably a good indicator, as well.
>
> Velocity and angle position are usually unreliable if the event isn't 
> captured on cameras, although it can be extracted if you have enough witness 
> reports (I usually figure that 1 in 10 reports are good enough to trust, so 
> you need quite a few; azimuth reports are usually much more trustworthy than 
> altitude reports).
>
> It is likely that most meteorites are the product of fairly unremarkable 
> fireballs. Most really spectacular fireballs probably don't produce 
> meteorites.
>
> Chris
>
> *****************************************
> Chris L Peterson
> Cloudbait Observatory
> http://www.cloudbait.com
>
>
> ----- Original Message ----- 
> From: "Tim Heitz" <midwestmeteor at earthlink.net>
> To: <meteorobs at meteorobs.org>
> Sent: Tuesday, May 12, 2009 5:59 PM
> Subject: (meteorobs) Information about observed fireballs
>
>
>   
>> Hi,
>>
>> I'm new to this site, could someone tell me how do we know observed
>> fireballs fell to the ground?
>>
>> How can I use this imformation gathered to determine if any material as 
>> made
>> it to the ground.
>>
>> To eliminate boring post and waste space please e-mail me off site.
>> TimHeitz at earthlink.net
>>
>> Best Regards,
>> Tim Heitz
>>     
>
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>   


-- 
Regards,
Eric Wichman
Meteorites USA
http://www.meteoritesusa.com
904-236-5394