[FPSPACE] Caves on Mars

[DSFPortree at aol.com]

Jens:

Earth-based telescopes can see Tunguska-sized objects. Recall that we spotted 
an S-IVB stage some years ago. 2006 W2 isn't a dinokiller, and amateur 
astronomers will be tracking it this coming Friday.

Besides, the fact is that Tunguska-sized objects only affect limited areas, 
and 75% are likely to explode over the oceans. An iron asteroid about the size 
of the Tunguska object exploded in the air over northern Arizona 50K years 
ago. It blasted out Meteor Crater and fried some mammoths and ground sloths 
grazing along the Little Colorado River. But 40 miles away, where I live, there was 
little more than a peal of distant thunder.

This is not to say that I'm opposed to space-based telescopes for asteroid 
detection, though they needn't be moon-based or particularly costly to do what 
we need. 

What about piggy-backing an asteroid transponder on an OSIRIS-type probe? 
It'd be a good proof-of-concept exercise and it'd be relatively cheap.

David


David S. F. Portree
author & educator
dsfportree at aol.com
(928) 226-1427
Flagstaff Arizona USA

DSFP homepage
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http://altairvi.blogspot.com/

"It's like when you're a kid, the first time they tell you that the world's 
turning and you just can't quite believe it because everything looks like it's 
standing still. I can feel it - the turn of the Earth. The ground beneath our 
feet is spinning at a thousand miles an hour, the entire planet is hurtling 
around the Sun at sixty-seven thousand miles an hour, and I can feel it. We're 
falling through space, you and me. Clinging to the skin of this tiny little 
world, and if we let go..." - The Ninth Doctor








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