[at-l] SuperVolcano?

[gregbrown at mindspring.com (Greg Brown)]

>
>
> PS.  If anyone is really desperate to become hysterical about  
> cataclysmic endings, some scientists are attempting to predict the  
> likelihood of earth being destroyed (read, human life extinguished) by  
> an asteroid of sufficient mass colliding with earth.  They feel it is  
> inevitable, given an infinite amount of time, but just wish to  
> calculate when.  Boy, those scientists are a humorous lot.
>
>
And we've had some close calls regarding large asteroids.  In July of  
2002 an asteroid roughly one mile across in size missed the early by  
75,000 miles.  Sounds like a large enough buffer but that is actually  
one third the distance between the moon and Earth.  In 1994 we had one  
the same size pass within 65k miles AND it flew between the moon and  
the Earth.  On Friday the 13th of April, 2029 we are going to get a  
very close call by an asteroid the size of three football fields.  It  
will also pass between the Earth and the moon and will be visible by  
the unaided eye at night over Europe.  There is a theory floating  
around out there that the moon was created by something the size of the  
planet Mars slamming into Earth which gouged out the moon.  Here is the  
webpage if you would like to explore that theory in more detail:
http://www.space.com/scienceastronomy/solarsystem/moon_making_010815 
-1.html

If you are ever out in Northern Arizona check out Berringer/Meteor  
Crater.  It's somewhat overpriced to see, but it is a very big crater  
in the ground left by something in the 50 kilogram range.

Here's a satellite picture from google (too bad it's not at a high  
resolution):
http://tinyurl.com/4rjzb

And if you are a history buff check out Tunguska, Russia.  Something  
slammed into Earth over this remote part of siberia, and nobody is  
quite sure what it was, but the shockwave was heard round the world and  
the explosion flattened everything within 75 miles AND it gave off  
enough energy to light the skies over Europe well enough to read a book  
at night for three days.  In the USA, on the East Coast, you could see  
a glow over the horizon for a couple nights after the explosion.

Ah, yes, I think I will take a hike to get my mind off this doom and  
gloom.

Greg