Asteroids: The *REAL* Threat to the Human race?

Feb 27 23:23 UTC 1997

Being a lover of teh stars, and of heavenly bodies in general, I"m quite
interested in the concept of asteroids hitting the earth in the furture. I
saw teh mini-seires and the geographic special. The latter states that large
asteroids have hit earth in the past and will inevitably hit in the furture.
There are many earth-crossing asteroids that have been discovered, but it is
those that have yet to be discovered that we must worry about most. If we are
in the path of a gigantic space-rock, what can we do to stop it? And what can
we do to preserve human life in the aftermath?

response 2 of 99:

Feb 28 07:42 UTC 1997

would the science fw please link this?

The "big ones" are only 6 km or so in diameter. An H-bomb makes that big a
splash. It would be tricky, but if the proper nudge were made at the
proper time and distance, the asteroid might be made to miss us. Might.
But is this really a threat? We've made it "OK so far" for several million
years.  The last major asteroid impact/extinction event was the K-T one,
wasn't it?  65Ma bp? I think we have more serious threats to concern
ourselves about for the next few centuries. We *know* that there will be
lots of problems due to human population growth, resource depletion,
global warming,, etc. 

response 4 of 99:

Feb 28 15:03 UTC 1997

yet what harm is there in determining reasonable preparations for a
realistically possible scenario?

one thing i remember from the TDC special was the idea of a near surface burst
causing the heated side of the rock to propel it sideways out of our path.
what is the comparative potential of applying the same tactic directly in the
path of the rock to slow it just enough to cause the timing of its
intersection with earth's obit to be delayed sufficiently to miss?

response 6 of 99:

Feb 28 17:28 UTC 1997

I have read that some scientists believe there is a 1 in a thousand 
chance that a young child alive today will be witness at some time in 
his/her lifetime to an asteroid collision with earth.  When such 
collision occurs, there will be massive geoclimatic shifts, ensuing 
environmental upheaval and many people will starve.  

Recently, material in the floorbeds of the Atlantic ocean, was 
discovered that is claimed to be scientific verification of the asteroid 
collision that caused the equivalent of a nuclear winter and caused the 
dinosaurs to become extinct.  Nature is usually cyclical.  What has 
happened once is usually going to happen again.

Maybe we know now what is going to cause Armageddon.  Sobering thought.

response 8 of 99:

Feb 28 22:33 UTC 1997

I only hope these fears arent used to revive support for the Star Wars missile
defense system.  We have betterthings to spend money on than weapons systems
to blow theoretical asteroids out of thesky.

response 10 of 99:

Mar 2 23:46 UTC 1997

I have to agree with Richard.  How aoften have asteroids hit the earth with
devastating effects?  Is it worth spending tons of money on?  I don't think
so.

response 12 of 99:

Mar 3 04:46 UTC 1997

It's happened quite regularly throughout the life of this planet.  Happened
in about 1912 in Russia.  knocked over about 50 square miles of trees.  People
might think it sucked if all of New Jersey just went away.  Then again, maybe
they'd like that.

response 14 of 99:

Mar 3 17:25 UTC 1997

re #11: So, you're willing to spend billions on a system that probably won't
work in the extremely unlikely event that something will happen?  

response 16 of 99:

Mar 4 09:29 UTC 1997

sdi, but i digress
  
there is no *immediate* problem, or the hubble & etc. would have
given some sort of alert.
  
however, that being said, there is a reasonable apprehension of the
planet earth playing pool with other celestial bodies.
  
no 'crash' program is even considered, rather a planet-wide buildup
for what is inevitable.

response 18 of 99:

Mar 4 14:14 UTC 1997

I think the chances of it happening in my lifetime are pretty much nil.
As a matter of fact, I am so sure of that I am willing to bet my life on it
by doing nothing. 

We should have an "Asteroid Fund" where people can voluntarily donate money
to save the human race. I am quite content to be thrown back into the stone
age if it happens (and if I am still alive). It will also answer an
age-old question: Will those who have the money now still have it if 
everyone started from ground zero? :-)

response 20 of 99:

Mar 4 16:17 UTC 1997

How inevitable? Oh, I'd say the chance of a person being killed by a 
small meteorite is much greater than the chance of death by a nearby impact,
in any given year. That's because there are so many more small meteorite
impacts than big ones. There are some million times as many 6 cm meteorites
hitting the earth as 6 meter meteorites (and 6 kilometer ones, which do global
damage, are some .0000000001 as frequent as 6 meter ones). Everyone has a
vastly greater chance of being injured by a falling tree, or falling off their
chair. 

response 22 of 99:

Mar 5 01:05 UTC 1997

Agora 87 <-> Science 19

response 24 of 99:

Mar 5 14:05 UTC 1997

There are 70 some earth orbit crossing asteroids known at the present time.
Thousands more could be out there that we haven't seen yet.  Teh Hubble isn't
used to track any of these, it is done by amatuer scientists, the same ones
that catch most of the comets.