[meteorite-list] NASA Announces Spectacular Day of the Comet (Deep Impact)

[MexicoDoug at aol.com]

Ron B. kindly forwarded:

>"In the world of science, this is the astronomical equivalent  
>of a 767 airliner running into a mosquito," said Don Yeomans, 
>a  Deep Impact mission scientist at JPL.

Sneaky NASA and Don, doing those back of the envelope orbital  calculations 
on the fly, ignoring the energy and momentum of the mosquito when  discussing 
the risk of orbital modification / earthward accidents.  Better  to speak 
truthfully when there is no need not to...It has the energy of shooting  a 767 with 
the most powerful airgun with the heaviest pellet, permitted under  British 
Law at the cockpit, of course.  British airguns are permitted much  more 
powerful than their European counterparts.

By the logic used, and  the examples made, one loses the idea with familiar 
mosquitos, in my  opinion.  The comet's mass is about 5.4 X 10^10 metric tons.  
That's  54,000,000,000 tons or 54 (USA small) billion metric tons.  A mosquit
o is  2.5 mg.  A half fueled 767 with cargo is about 115 metric tons.  But  
the whole point of it is the energy of impact and the speed.  A mosquito is  the 
wrong choice to illustrate this. 

Thus, the 767 is 46 billion times  times more massive than the mosquito after 
dinner, and the comet is 146 billion  times more massive than the 0.37 metric 
ton impactor.

So amusingly it is  more in the range of a mosquito hitting a 747 in the 
cockpit though the mosquito  would have the relative energy and hardness of a 
bullet, and the energy of 20  billion Joules (=4.7 million food calories or in 
common terms, that contained in  the fat of 16,000 Big Macs burned completely at 
100% efficiency).  The fat  in a single Big Mac can power threehundred-sixty 
458 Magnum bullets at MUZZLE  velocity, each of which could easily penetrate 
through three persons before  stopping.

Now those mosquitos and Big Macs can be deadly,but what about  those half ton 
copper hammers?????

Saludos, Doug
 
OK if you want to use momentum, go ahead, ...