[meteorite-list] Comets vs. asteroids, and AD

From: E.P. Grondine <epgrondine_at_meteoritecentral.com>
Date: Wed, 14 Jan 2009 10:09:00 -0800 (PST)
Message-ID: <293395.7188.qm_at_web36904.mail.mud.yahoo.com>

Hi Rob -

(sorry about that. Yes, my short English name is ED, but let's stick with E.P., for "Extended Play" instead)

You wrote:

> You're not going to trip me up when the subject matter is solar
> system dynamics, comets, asteroids, optics, physics,
> orbital mechanics or general astronomy, so please don't even
> try.

Okay.

> Yes, the SRBs were *responsible* for rupturing that tank, but that
> wasn't a fault of the solid propellant.

But when you present me with rationalizations like this one, please excuse my doubts.

Several years ago the problem of dealing with the comet and asteroid impact hazard was looked at by a skilled team of engineers at NASA Langley. Their solution was CAPS - and they're the folks you need to discuss it with. If you have any detailed criticism of their conclusions, go for it.

Their conclusion didn't surprise me much, as I had made a guess at it about 4 years earlier:

http://www.geocities.com/epgrondine

When I found out how bad the problem was, I simply threw at it the largest telescope I had seen, one proposed by Bush Snr's science advisor, and figured out the cheapest way to build it.

> The point I'm trying to illustrate is that spotting a 50-meter extinct
> comet at two or three lunar distances is not a problem for current
> ground-based survey instruments (provided the solar elongation is greater > than, say, 70 degrees). Yes, a Moon-based instrument could detect objects > at lower solar elongations, but the poor phase angle unfortunately means > that you would still have very little warning time -- less than 24 hours.

Given the staggering high velocities of these things, lunar distances don't mean much. The requirements are all threats, including Long Period Comets and Tunguska type impactors. The warning REQUIREMENTS are 45 minutes for a Tunguska type inbound, with no repeat pass-bys, so that people can take shelter; at least 3 days for 200-300 meter, to allow coastal evacuation; better would be weeks to months for nuclear mitigation; and simply as long as possible for Long Period Comets, so that SSHCL diversion can be used.

> That's a cop-out -- I'm not asking the Chinese, I'm asking you.
> How much money are you willing to throw at this perceived deficiency?

How much do I want thrown at this problem? At least the same amount some folks want to spend flying a few men to Mars for a few days. Since we're returning to the Moon anyway, why not do something useful while we're there?

I read today that the NASA astronomy budget was $1.2 billion last year. NEO detection got about $3.4 million. What's wrong with this picture?

(And why didn't SWRI get money to study the Moon's impact record? And why is the LRO not equipped with some means of determining what created the different craters on the Moon? Where is our solar system accretion model with all crater data accounted for?)

> If you were presenting a proposal to Congress or the American people, do > you really think your ancient Chinese examples would be that persuasive?

No, but the death of 95% of the people living in North America due to impact in 10,900 BCE might do it. The problem was that I had a stroke along the way. And since this is the meteorite list, here's the AD:

In the past two years we have had impact products evidenced at 10,900 BCE
and 546 CE. Some of you may be realizing by now what an extraordinary bargain your copy of my book "Man and Impact in the Americas" is.

Personally signed copies of the first edition of my book are still available to meteorite list members for $20 plus $5 priority mail shipping US, or plus $15 for overseas shipping (Fair warning - it helps if you are pretty fluent in English).

What do you get for your money? Hundreds of pages of small type filled with typos, not enough illustrations, and a correction sheet pasted inside the front cover - but still, the finest single volume introduction to the first peoples in the Americas that you can read, in my opinion. (Second fair warning - I cover impacts in this book, and not meteorites, and most of the impacts were comet fragments. Sorry, but its not a hunting guide - but then if it were, I suppose that I'd be the one doing the hunting, even with my stroke, now wouldn't I?)

PS - For those of you who already have copies, email me and I'll send you a doc file of the correction sheet, if you want one - I wouldn't paste it in your copy though, but simply insert it after the front cover - you'd reduce the first edition collector value of your copy.

PS 2 - As Ares 1 is suffering combustion oscillations bad enough to black out the crew, a copy of "Man and Impact in the Americas" would also make a great going away present for Mike.

Good Hunting,
E.P. Grondine
Man and Impact in the Americas


--- On Tue, 1/13/09, Matson, Robert D. <ROBERT.D.MATSON at saic.com> wrote:

> From: Matson, Robert D. <ROBERT.D.MATSON at saic.com>
> Subject: RE: Comets vs. asteroids
> To: epgrondine at yahoo.com, meteorite-list at meteoritecentral.com
> Date: Tuesday, January 13, 2009, 9:59 PM
> Hi E.P.,
>
> I hesitate to respond from work since the oddities of the
> MetList prevent my posts from reaching it when I reply from
> my work e-mail address (perhaps to the relief of many
> members).
> Nevertheless, I'll press on and forward the message
> from my
> home account when I get there (though the subject matter is
> veering off-topic, and few people care about this subject).
>
> > Hi Bob -
>
> [FYI, "Bob" is not my name. I realize that
> it's a popular
> short version of "Robert", but I have never
> signed an email
> by anything other than Rob.]
>
> > There were so many falacies in your post that with my
> stroke
> > damage I let some major howlers get through in my
> reply.
>
> E.P. (Ed?) -- I don't post falacies, I post facts. On
> those
> occasions when I post opinions, I label them as such.
> You're
> not going to trip me up when the subject matter is solar
> system dynamics, comets, asteroids, optics, physics,
> orbital
> mechanics or general astronomy, so please don't even
> try.
>
> > Actually, turbine, combustion chamber and propellant
> line
> > failures give some warning, and the (s)hutdown/abort
> systems
> > can be brought into play. Not so with solids, which
> have
> > sudden catastrophic failure modes ...
>
> I don't think I need to remind you that it wasn't
> the Shuttle's
> SRBs that exploded -- it was the External Tank. Yes, the
> SRBs
> were *responsible* for rupturing that tank, but that
> wasn't a
> fault of the solid propellant. If the Shuttle had been 100%
> solids it wouldn't have exploded. The crew would still
> have
> been lost (since there was no escape option in 1986), but
> *had*
> there been a rapid egress system, their chances of survival
> certainly would have been better if they hadn't been
> riding
> a liquid bomb.
>
> > Why Mike resized the CEV so that it exceeded EELV
> capablities
> > and required a large solid launcher is a great
> question. Given
> > your work with Griffin in SDIO, I would ask about the
> need for
> > large solid launchers for defense purposes, but then
> this is a
> > public forum. I assume Garver, Ladwig, and Obama
> already know,
> > they'll share want they want to with us sometime
> next week...
>
> Completely off-topic and of no interest to me.
>
> >> Well, where do you draw the line on the expense of
> your
> >> "insurance policy"
>
> > Ask the Chinese. Their national emblem is a dragon
> commemorating
> > a comet; their first emperor was killed in an impact
> event; they
> > lost nearly all their commercial shipping fleet to
> impact mega-
> > tsunami around 1431 CE, which left them open to
> foreign attack
> > and centuries of suffering.
>
> That's a cop-out -- I'm not asking the Chinese,
> I'm asking you.
> How much money are you willing to throw at this perceived
> deficiency? If you were presenting a proposal to Congress
> or
> the American people, do you really think your ancient
> Chinese
> examples would be that persuasive?
>
> > I haven't broken CAPS out into CZ5 launches yet,
> to come up with
> > remin costs. Whatever the cost, the value returned by
> CAPS far
> > exceeds the value of flying a few men to Mars for a
> few days.
>
> To average citizens in 2009 trying to stay in their homes
> and
> feed their families, I'd say there was little value in
> either
> activity. The only way you'll get their attention is
> through
> extortion: perhaps threatening to deprive them of American
> Idol or The Bachelor. --Rob




      
Received on Wed 14 Jan 2009 01:09:00 PM PST