[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Cometary meteoroids landing on sea?

Hello group,

According to the 'FAQ on Fireballs and Meteorites' from Jim Bedient
posted recently on this group, cometary meteoroids make up 38% and 
carbonaceous chondrites another 33% of total >-4 magnitude fireballs.
Combined this will be ~70% of all the brightest fireballs. 

If this kind of material hits a firm surface I guess most of it will
explode or be chrushed to dust - at least the cometary material.

BUT - what will happen with such material if it hits the sea or a lake.
I guess the carbonaceous chondrites will sink at once, but what about the 
cometary material?

Comet surfaces are frosen gasses and liquids (water) - 'the dirty snowball'.
If this material survives to the sea surface, what will happen?
Let's also assume it is one of the smaller fireballs, so that it has achieved a
terminal velocity of a free fall ~200 km/h. (Perhaps also somewhat slower 
because of the light material in this case.) This means that the meeting with
the water will not be too hard. 

Since ices are lighter than water, would it not be possible for this object to
resurface again because of the buoyancy?
Let's also assume that the material 'is on fire' in the later stage of the
Not necessarily all of the fire will be extinguished because of the meeting 
with the water body. If it is the dark part of the day, is it possible to
have a floating 
glowing/burning object on the sea surface for some time - until the waves and 
melting eventually will turn out the warmth and the remains will sink and

So I wonder:
Have ever such a phenomenon been observed and discussed in the history of
Or is there a possible flaw in the above reasoning?

(Searching for it afterwards will be hopeless I guess (assuming shallow
because it all have melted. Or could there be a significant part of cometray 
material that is stony material?)

Any comments about this will be appreciated.

Bjørn Sørheim

List Archives are located at http://www.meteoritecentral.com/list_best.html
For other help, FAQ's and subscription info and other resources,
visit  http://www.meteoritecentral.com/mailing_list.html