[meteorite-list] Crackpot in the news

From: Sterling K. Webb <kelly_at_meteoritecentral.com>
Date: Sun Apr 24 04:19:29 2005
Message-ID: <426B566F.D4B3EE4F_at_bhil.com>

Hi!

Darren Garrison wrote:

> I'm still wondering over this line:
>
> "Bush said it is common to see meteorites, pieces of a meteor, hitting the Moon's surface, however,
> but it was a rare occurrence to catch a meteor strike."

    Both statements are ridiculous, of course. It would be an incredibly rare event to see or photograph.
As I recall, there is only one good candidate for a photo of a meteor strike on the Moon. It was, I think,
back in the late 1950's (1957?). I read about it (and the arguments that insued from the claim) in Sky &
Telescope magazine and I'm sure the article is there in my 52 year deep stack of Sky & Telescope's. But I
ain't gonna search for it.
    The interesting thing is, at that time, most geologists (especially British and Australian ones) were
absolutely convinced that the Moon was geologically active and that ALL the craters were volcanoes.
Impacts? Tut, tut, they said, unlikely. So the arguments were about whether what had been photographed
was an impact event or a volcanic eruption!
    So powerful was the hold of the volcanic model on some geologists that I have a marvelous 1976
Australian text (which I bought for the section on Australian tektites) that resolutely affirms that the
lunar landscape was all formed by volcanic action. This was years after we had already been to the Moon
and seen a small planet's worth of evidence that it WASN'T volcanic. The author dismissed the Apollo
observations by remarking that those fine fellows were, after all, aviators, not geologists!
    As for impacts, no problem. The seismometers left behind on the Moon recorded not only "moonquakes,"
but a number of impacts, including a series of five of what were almost certainly beta Taurid meteor stream
objects. Each one was estimated at a weight of 2-5 tons and with a terminal velocity of about 24 km/sec,
all five of them on one day! But no photographs...
    On the other hand, the Moon has been mapped with some accuracy for over two centuries and no one has
come up a crater big enough to have been seen that just wasn't there in the past, which puts a limit on the
frequency of large impacts. In fact, after two centuries, there have been no verifable instances of any
lunar feature changing in appearance, at least that can't be plausibly explained by observer limitations
and errors.
    Most of us here on the List are familiar with NASA's Astronomy Photo of the Day webside:
    <http://antwrp.gsfc.nasa.gov/apod/astropix.html>
    But did you know there's a Lunar Photo Of The Day website (since Jan. 1, 2004) for us "loonies"?
    <http://www.lpod.org/>
    And of course the Malin Space Science Systems (Mars Observer Camera) web site has a Mars Photo Of The
Day (along with its archive of 187,000 Mars images):
    <http://www.msss.com/>
    And just so the Earthlings don't feel left out, an Earth Photo Of The Day web site:
    <http://epod.usra.edu/>
    Can't forget the Earthlings...


Sterling K. Webb
Received on Sun 24 Apr 2005 04:18:55 AM PDT