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

Re: (meteorobs) Those Meteor Movies - a review

Kevin sends the following message->

>In a message dated 98-07-15 23:31:32 EDT, you write:
><<Question: How many millions of years would it take for a Texas
>sized asteroid to collide with earth ? What are the real probabilities
>of a VERY unlikely event like this?>>
>
>There was one scientist on either the Learning Channel or the Discovery
>Channel when they were doing documentries to tie in with the two movies.
>Anyway, he said that we will have as much warning as the dinosaurs did.  How
>many times have we all read in Sky & Tel that an asteroid came withing the
>Earth-Moon orbit and we didn't even notice it until it was already outbound. I
>guess we could start a grass roots movement within all the amateur
>obseervatories world wide to have a focus group within to look for these
>things.But we don't have the technology to do anything about it anyway, we
>can't blow them up (a popular solution), we don't have the solar sails that
>have been talked about, so the best thing to do is not even worry about it


Kevin and meteorobs,

A Texas size asteroid is gigantic for an asteroid. We would have centuries
or more of warning from an asteroid this size (there are only a few in
existence) unless one like that somehow came from deep space beyond Pluto.
The probability of that should give you little worry-about the same I
imagine as all of meteorobs winning the sweepstakes. Possible but not very
probable. The close calls you write about above are no laughing matter but
they were house-sized asteroids, large enough to do a lot of harm but
probably not civilization enders.

Also there is active research now looking for the smaller ones. We even
have a couple of students here doing a search. NASA just announced a group
that will coordinate the search and recording of such objects. Things are
slowly being done although Clinton did line-item-veto some money for an
associated project probabily becasue of the "giggle factor" and hopefully
these movies and the associated TV fallout may change that public
perception a little making the politcal funding climate more favorable.

The thing is we do have the technology to develop equipment that can do
something about these objects if we have enough warning, hence the need for
a search and catalog of such objects. A very slight change in orbital
velocity and direction years in advance of an impact can cause a miss. (Not
a very exciting Hollywood story line, is it? Scientiist find killer
asteroid that will collide in 50 years. Automatic probe flys out to
asteroid and deploys a gigantic mylar solar sail [or ion engine or
whatever] which slowly changes the velocity. Everyone on Earth goes out as
night decades later and watch this thing glide by the Earth.)

I for one lament the billions thrown away on the internation space station
which is just an engineering project to give the shuttle something to do,
when "real science" gets pennies that are left over.

Hold the hate mail all you shuttle and space station lovers out there. You
will never convince me and I won't convince you, but I hate that my tax
dollars have gone in that direction. The shuttle has sucked up a bunch of
science money and proved much more costly than expected. We should have
built one shuttle as an experimental vehicle and either kept the venerable
Saturn launch vehicles active or made a reusable unmanned launch vehicles
to do real science. Yes we do some "science" in orbit every time the
shuttle goes up, but is it high priority science or just something done
because we have the shuttle?
Every shuttle launch costs about as much as the last successful Mars probe.
That is a lot of money to find out how flames work in zero gravity or what
frog eggs do in space. Meanwhile we are having to use gravity assist from
Venus and Earth flybys to get our big probes out beyond Mars because now in
hindsight we think some upper launch stages are too dangerous to put in the
shuttle cargo bay. Our probes then have to be lighter and with the years of
added flight time needed for gravity assist are more likely to have a
failure before making to the science destination. Also please note I gave
four years of my life for a project for shuttle launch so I speak somewhat
as an insider on this issue.

Well Kevin I guess this was more than my 2 cents worth on the Texas size
asteroid.

Terry


*****************************************
Terry Richardson
Department of Physics and Astronomy
College of Charleston
Charleston, SC 29424
pager #937-1048
note new area code for the SC Lowcountry!
843 953-8071 phone
843 953-4824 fax
http://www.cofcdot edu/~richardt/
*****************************************
References: