Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_3/V15NO396.TXT

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Date: Sun,  8 Nov 92 05:06:48
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #396
To: Space Digest Readers
Precedence: bulk


Space Digest                Sun,  8 Nov 92       Volume 15 : Issue 396

Today's Topics:
                     Duncan Steel on Swift-Tuttle
                       Hubble's mirror (2 msgs)
                  Hubble's mirror  or Really Costar.
                      Interesting Text on UFO's
                          Man in space ...
                          Man in space ... )
                             NASA Coverup
                    Space_nz. Information Service.
                Swift-Tuttle Comet a threat to earth?
    Ten embarrassed questions about the moon (very long) (2 msgs)

    Welcome to the Space Digest!!  Please send your messages to
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    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: Sat, 7 Nov 1992 23:32:06 GMT
From: Dave Tholen <[e-mail]>
Subject: Duncan Steel on Swift-Tuttle
Newsgroups: sci.space,sci.astro

Jeff Bytof writes:

>> (3)  There has been a lot of bull written in these columns about
>>      P/Swift-Tuttle and whether it will hit the Earth and what the
>>      consequences might be.

> How true.  I have not yet seen ONE independent confirmation of
> the orbital calculations and a sober error analysis.  For all we
> know, this could be somebody's mistake.

The orbit solution calculations were performed independently by both Brian
Marsden and Suichi Nakano, as clearly indicated on the original IAU Circular
announcing the possibility.  I do not know Nakano that well, but I am
confident that Marsden was quite sober when the calculation was performed.
Being one of the experts in this field, I seriously doubt he made a mistake.
Ted Bowell and Karri Muinonen could perform their style of error analysis
recently developed for near-Earth objects, but it wouldn't do much good,
because I haven't seen their technique involve uncertainties in the
non-gravitational forces yet, and it's these non-gravitational forces
that are causing the large uncertainty in the time of perihelion passage
in 2126.  Marsden is right:  we need to follow the comet as long as possible
this time around to do a better job of computing where it will be the next
time around.  We need more data, not a better error analysis!

I wish to point out that the bull people have been reading in this newsgroup
has not been coming from the experts, but rather from readers whose rampant
speculation has gone wild.  As for what the consequences might be, it should
be noted that the experiment has not been done (unless you want to count the
K-T event 65 million years ago, though people weren't around to observe and
document the effects), so we have to rely on theoretical calculations.
Literature is available (such as the summary in the Spaceguard report) as
to what we believe the consequence could be, so readers need not rely on
sci.astro.

------------------------------

Date: Sat, 7 Nov 92 19:06:14 EST
From: John Roberts <[e-mail]>
Subject: Hubble's mirror

-From: [e-mail] (Claudio Egalon)
-Subject: Re: Hubble's mirror
-Date: 7 Nov 92 20:03:21 GMT
-Organization: NASA Langley Research Center, Hampton, VA  USA

-*However* as  I recall (and I may be wrong) the error in the RNC
-came along because the WRONG surface in the instrument was
-providing the reflection and not that because the instrument was
-built improperly. Aparently there was an scratch in a surface that was
-suposed to be black, for absorbing incoming radiation, and it was this
-scratch that worked as the WRONG reflecting surface.

NIST provided a calibration rod of a very precisely measured length, to be
used in the setting of the reflective null corrector. To further assure
the greatest possible accuracy, the spec called for the end of the rod to
be covered by a metal end cap (painted flat black) with a hole in the middle,
so the optical instrument used in the calibration could only look at the
center of the rod. Somehow a flake of paint was knocked off the end cap,
leaving a shiny spot. The Perkin-Elmer team managed to get the rod in
place off-center, and picked up the reflection off the shiny spot. They
assumed that this was the end of the calibration rod, so the adjustment
was off by the thickness of the end cap.

John Roberts
[e-mail]

------------------------------

Date: Sun, 8 Nov 1992 00:18:01 GMT
From: Rick Kirchhof <[e-mail]>
Subject: Hubble's mirror
Newsgroups: sci.astro,sci.space

In article <[e-mail]> [e-mail] (Stick,CommoSigop) writes:
>In <[e-mail]> [e-mail] (Gerard M. Foley) writes:
>
>>[e-mail] (Donald H. Locker) writes:
>
>>> Now that I know a little about mirror-making, I'd like to hear again
>>> how the Hubble mirror contractor messed up the figure of the main
>>> mirror.  I understand it has spherical aberration, but wonder how
>>> [Rockwell?] managed to do that.
>>>
>>It wasn't Rockwell (I forget axactly who it was, but it was an
>>otherwise reputable New England outfit) and put briefly, they
>>fouled up the test, performing it incorrectly, and never
>>checked by any independent method.
>
>   According to Dr. Steve Maran, who works on the HST project at the
>Goddard Flight Center, and who was recently a guest lecturer at my college,
>none of the above is true.  The company that ground the mirror did it
>exactly to the specs they were given.
>
>   The specs were wrong.
>
>
That is not the case.  The primary mirror was produced by Perkin-Elmer.
This has been the subject of MUCH investigation by NASA.  The end result
is that Perkin-Elmer manufactured a large primary mirror to exceedingly
accurate standards obtained from a incorrectly manufactured optical test
cell they also made.  The "smoking gun" is in their mirror lab, as NASA
requested all relevant project materials mothballed upon project
completion.

To be fair, the quality of the mirror was extremely good as tested by
their rig.  If the test cell had been correct, the mirror would have been
correct.  Perkin-Elmer just did not produce what NASA asked for.

It is ironic that several other types optical tests could have shown a
gross error such as this.  They were never used.  In addition, Eastman
Kodak, who also made a primary mirror to the design specs, requested
that the better of the two mirrors be used.  This was never done.

For independent verification of all of this, see several issues of SKY &
TELESCOPE.  The subject has been reported several times there.

--
Rick Kirchhof   Austin, Texas                   | Experience is what you
Domain: [e-mail]                   | get when you don't
Bang path: ...!cs.utexas.edu!peyote!posms!rick  | get what you want.
===========================================================================

------------------------------

Date: 7 Nov 92 23:59:37 GMT
From: Henry Spencer <[e-mail]>
Subject: Hubble's mirror  or Really Costar.
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (_Floor_) writes:
>] As for an annoying problem, the South Atlantic Anomaly and flapping of
>] the solar arrays give a lot more headaches around here...
>
>What is the South Atlantic Anomaly?

This is perhaps a candidate for the FAQ list...

Most people know that the Earth's magnetic poles aren't located at its
geographic poles, but it's less well-known that Earth's magnetic center
is not at its geographic center either.  This means that the Van Allen
belts, which follow the magnetic field, are slightly off-center, i.e.
they are slightly closer to the Earth on one side and slightly further
away on the other side.  The area where they are closest is in the South
Atlantic.  In that area, known as the South Atlantic Anomaly, the Van Allen
belts come down low enough that radiation intensity in low Earth orbit
is noticeably greater there.  This is troublesome both to astronauts and
to sensitive electronics; for example, it's common for astronomy missions
to suspend operations during passage through the SAA because the radiation
causes unacceptably high noise levels in their sensors.

In HST's case, some of its computer hardware is more radiation-sensitive
than it was supposed to be, and this causes trouble during SAA passage.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

------------------------------

Date: Sun, 8 Nov 1992 01:02:46 GMT
From: Don Allen <bilver!dona>
Subject: Interesting Text on UFO's
Newsgroups: sci.space

In article <.60.0@> @ writes:
>
>          Fellow computer enthusiasts,                            11-24-89
>            What follows is a transcript of a 45 minute lecture that I at-
>          tended on 11-17-89 at the "Whole Life Expo." in Los Angeles,
>          California. Speaking was Mr. Milton William Cooper who I first
>          became acquainted with through a text file I downloaded from a
>          local computer BBS. The file dealt with the subject of UFO's and
>          our government's concealment of the truth about them in such a
>          way that it made a lasting impression on me, which is why I
>          attended his lecture; to learn more. Please forgive my probable
>          misspelling of some of the proper names in the transcript which
>          follows and allow that I have taken it as best I could, word-
>          for-word, from a less than acceptable micro-cassette recording.
>            If you are as moved by what you are about to read as I was in
>          hearing it first hand, I ask that you please spread it as far
>          and wide as possible. Upload it to every BBS in your reach and

Yet another posting of Bill Cooper's garbage. You would be better advised
to spend some time doing real research. FYI, Bill Cooper has been
throughly dis-credited by his *own* words.

I was around when Cooper first appeared on ParaNet and also witnessed
Cooper get booted off that Network by the (then) administrator, Jim
Speiser. The reason? When Cooper made these incredible claims and
when the ParaNet members sought more clarification, Cooper's response
was to become hostile and then start labeling _anyone_ who dared
to question him as a "Govt agent". In short, Cooper has been de-bunked
by the best of them in UFOlogy, mainly because his facts aren't checkable,
much like the claims of John Lear and Robert Lazar.

I get so tired of following up and straightening people out on Cooper's
BS..by the way, if you waste your money on his lectures or tapes, you
soon discover his "facts" are prevaricated and twisted. If you waste
your money on his book, "Behold a Pale Horse" , you discover that Cooper
makes claims such as William Greer (JFK's driver) was the one that
shot JFK. Be advised that this lunatic includes in his book, the
whole "Learned Protocols of the Elders of Zion" and he ACTUALLY
BELIEVES THEM!

You be better advised to move on and read anything by Jacques Vallee
or Dr David Jacobs, and throw Cooper's BS into the trash can where
it properly belongs.

Don



--
<*> Don Allen <*>             1:363/81.1 - Fidonet #1 - Homebody BBS
[e-mail] - Internet   1:363/29.8 - Fidonet #2 - Gourmet Delight
88:4205/1.1  - MUFON Network  1:3607/20.2  -- Odyssey - Alabama UFO Net
NSA grep food: Aviary, Ed Dames, Los Alamos - Majestic - Jason - RIIA - UN

------------------------------

Date: Sun, 8 Nov 1992 00:59:56 GMT
From: Henry Spencer <[e-mail]>
Subject: Man in space ...
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Eric Goldstein) writes:
>I vividly remember a NASA publication entitled "14 seconds of useful
>consciousness."  The claim was that, in case of rapid decompression, a
>human had 14 seconds to fasten a helmet, close a door, throw a switch, or
>whatever.  Not that you were seriously injured in that time, but you would
>be incapable of taking whatever actions were necessary to save your life
>after 14 seconds.

I haven't seen this publication.  I would suspect that the number assumes
you are taken by surprise, and is based on how much consciousness you can
expect before anoxia starts taking your brain down.  As Clarke has pointed
out, if you *expect* the decompression, you can boost your internal oxygen
supply considerably by hyperventilating first.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

------------------------------

Date: 7 Nov 92 22:13:05 GMT
From: Andrew Haveland-Robinson <[e-mail]>
Subject: Man in space ... )
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:

>In article <[e-mail]>, [e-mail] (Edward V.> Wright) writes:
>> In <[e-mail]> [e-mail] (Andrew> Haveland-Robinson) writes:
>[reference to orginal posting has been lost.  It's denoted by ">>>" here.]
>>>>   What will happen if the space suite of an austronaut gets ripped
>>>>in space ?
>>>>   Some of us recon that he will explode while others that he will end up

>>>>with lots of bruises!!. One thing that all of us agree, is that it is not
>>>>going to be a very healthy activity.
>>
>>>Well Nick, my feeling is that he would nearly explode.
>>
>> Well, Andrew, it's like this.  The universe just doesn't care how
>> you *feel*.
>>
>[explanation of what really happens deleted]
>
>> All of this information has been publicly available for *decades.*
>> So why do self-styled experts keep making up absolute nonsense
>> instead of just reading the relevent literature?
>
>Actually you have three choices:
>
>1. Make up absolute nonsense.
>2. Read the relevant literature.
>3. Ask the readers of Usenet.
>
>Choice 3 is not always appropriate, especially when 2 is available in
>an almanac or encyclopedia.  In this case it wasn't a bad idea, but I
>told Nick to use the fourth option:
>
>4. Check the sci.space FAQ to see if the question is answered there.
>
>As for Andy, I suppose he took what he knew about physics and biology
>and speculated about the answer.  That doesn't seem to deserve Ed's
>nasty tone... or does it?  You're allowed to be wrong around here, but
>you have to put up with the kidding. E.g.:
>
>Evidently Andy has seen *Total Recall* but not *2001*, or, if he's
>seen both, he believes the former has more accurate science than the
>latter.

Thanks for the support Bill - as I said it was just a feeling - without
experience or knowledge of the facts.  (I have seen 2001 but not Total
Recall)..  Now, if just the head was exposed to a vacuum...

I understand Ed's tone - it's easy to be critical if you know the subject
inside out (perhaps I'd do the same if a silly notion came up in my area
of expertise...  :-) , no, I'd try to be a little more circumspect...)

I'm sure that an awful lot of people too shy to postulate have benefited
something from this thread - I have!

Andy.

+-----------------------------------------------------------------------+
| Haveland-Robinson Associates   | Email: [e-mail]         |
| 54 Greenfield Road, London     |        [e-mail] |
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+-----------------------------------------------------------------------+
> Some dream of doing great things, while others stay awake and do them <

------------------------------

Date: 7 Nov 92 23:42:20 GMT
From: Josh 'K' Hopkins <[e-mail]>
Subject: NASA Coverup
Newsgroups: sci.space,alt.conspiracy

[e-mail] writes:

>                    TEN EMBARRASSING QUESTIONS ABOUT THE MOON

I would be embarrassed to post something this silly too.  Although it may be
a lost cause, I'll attempt to clear up this mess.

>   1.) Where did the moon come from , and how did  it  attain  it's  present
>       orbit?

"Snarfy"  (please tell us your real name) lists the three pre-Apollo theories
of Lunar genisis - fission, capture and creation with the Earth.

>     However,evidence gathered by the Apollo  missions  indicates  that  the
>   moon  and  earth  differ  greatly in composition.  Scientists now tend to
>   lean toward the third theory -  that  the  moon  was  "captured"  by  the
>   Earth's  gravitational  field  and  locked into orbit ages ago. There are
>   incredibly   difficult   celestial   mechanics   involved   in   such   a
>   capture.

There are indeed.  That explains why very few plantary scientists take it
seriously.  The current theory of Lunar genisis holds that a Mars sized body
collided with Earth in its early history and the reulsting debris formed the
Moon.  This hypothesis has beed modeled on supercomputers and is consistant
with the evidence of massive collisions in the early solar system.  It also
explains the difference in makeup of the two bodies.

>     Newton's  Laws  of  gravitation  would  almost  certainly  have
>   assured  an  acceleration  great enough to send it out into the depths of
>   space  again.   The  logically  consistent,  but  socially   unacceptable
>   alternative  to  this conclusion is that a steering or braking "manuever"
>   had been performed by some mechanism "aboard" the  moon.

"Logically consistant" maybe.  Sensible no.

>   2.   Is  the  "  apparent " size similarity (as viewed from earth) of the
>     sun and moon a mere coincidence?

>    Yes. The fact that the moon subtends an angle of arc, as viewed from the
>   earth  ,  equal  to that of the sun ,is a " coincidence" which causes the
>   occasional solar eclipse spectacle . Only the Earth , alone  of  all  the
>   planets  in  the  solar  system , is known to harbor life and a satellite
>   with this peculiar quality.
>   The theory that the moon was placed here  by
>   intelligent  being(s) as a sort of "planet marker " , is only a  theory .

You can say that again.  The Moon only has the correct apparent diameter during
certain parts of its eliptical orbit.  Sometimes it's too far away, resulting
in an annular eclipse in which you can see the sun around the Moon.  The idea
that aliens would need to move astronomical bodies around just to remeber which
was which is plain silly.

>    3. Why are moon rocks so much older than earth rocks?

>     99 percent of moon rocks brought back turned out upon  analysis  to  be
>   older than 90 percent of the oldest rocks that can be found on earth . If
>   we  assume  that the moon came from a different area of the solar system,
>   where the component material might have been different  ,this  assumption
>   would  still  not  account  for  the  disparity in the average age of the
>   matter composing the two bodies.

You haven't disccused the average age of the matter, you've discussed the age
of the rocks.  Rocks are "born" when the material they are made of cools off
enough to become solid.  The Moon would have cooled much sooner than Earth
because of its size.  Old Earth rocks would long ago have been subducted into
the mantle and reformed.  Finding Earth rocks as old as lunar ones would
disrupt the current theory, not support it.

>  4. Why are the "maria" or "lunar seas" located almost entirely on one side
>     of the moon?

The Moon is not an evenly distributed body, due in part to gravitational
gradients.  Maria formation would be more likely to occur where the crust is
thinner - on the near side.

>  5. Was rustproof iron found on the moon ?

No, and you comments to the contrary are silly.

>  6 . Is the core of the moon hot or cold ?

"Scarfy" makes some strange comments here and a few logic leaps that lost me.
The core of the Moon is solid.  This explains its weak and disorganized magnetic
field and the lack of siesmic activity.  This also makes sense given the small
size of the Moon - it would have cooled faster than earth.

>  7. Were immense clouds of water vapor ever observed on the moon?

>     The few lunar excursions indicate that the moon is a  very  dry  world.
>   But after Apollo 15, NASA experts  were  stunned  when  a
>   cloud  of  water vapor more than 100 square miles in size was detected on
>   the  moon's  surface.  NASA  officials  suggested  that  two  tiny tanks,
>   abandoned  on the moon by U.S. Astronauts, had somehow ruptured. But  the
>   contents of  these  tanks  could  not  have  produced  a  cloud  of  such
>   magnitude.

Why not?  It doesn't take much to mess with the Lunar atmosphere.  I've read
that it roughly doubled in mass when the Apollo rockets lit up.

The water vapor appears to have come from the moon's interior.
>   Mists, clouds and surface changes have been allegedly seen over the years
>   by  astronomers  .   For  instance  , six astronomers in the last century
>   claimed to have seen a mist which obscured the details on  the  floor  of
>   the  crater Plato. Clouds of any kind would be an extremely odd phenomena
>   on the moon, because of the supposed low gravity, which presumably  could
>   not  hold an atmosphere.  Water trapped beneath the surface, then venting
>   by some unknown process , is one possible explanation - but then what (or
>   WHO) is "letting off steam"?

Trapped deposits of volatiles are not inconsistant with current understanding
of the Moon.  They're just rather rare.  By the way, the Moon can and does
hold an atmosphere.  It's just very thin.

>  8. What caused the "Glaze" on the lunar surface?

>     Lunar  explorations  have  revealed  that  much of the lunar surface is
>   covered with a glassy glaze , which indicates that the moon's surface has
>   been scorched by an unknown source of intense heat.   Expert's  analysis
>   shows  that  this  did not result from massive meteorite impactings.

Could you give references for this please?

>  9. What are "mascons" and how did they get there?

>     In 1968 ,tracking data of lunar orbiters first indicated  that  massive
>   concentrations  (mascons) existed under the surface of the circular lunar
>   maria.  NASA  even reported that the gravitational pull caused by themwas
>   so  pronounced  that  the  spacecraft  overhead   dipped   slightly   and
>   accellerated  when  flitting  by  the  lunar  plain  , thus revealing the
>   existence of these hidden structures,  whatever  they  are.  Calculations
>   show that they are enormous concentrations of dense heavy matter centered
>   like a bull's eye under the  lunar  maria.  NASA  has  never  offered  an
>   explanation of their existence.

The last statement is a flat out lie.  The mascons (mass concentrations) are
the remains of large meteorites buried under the lunar maria.  The do indeed
have interesting effects on the gravitational and magnetic fields, but there
is nothing bizzare about them.

>   10. Is there anything "funny" about the moon?

>     People  who seem to be overly "obsessed" about the moon will often tell
>   you that the moon is indeed endowed with "strange" powers  that  have  an
>   effect  on thier lives. These people are sometimes called "lunatics." The
>   fact that you have  been  reading  these  "NASA  Moon  Coverup"  articles
>   through  to  this  point  indicates that YOU may have undiagnosed lunatic
>   "tendencies", and should ,perhaps ,see your doctor immediately (just  for
>   a  check-up).  Your doctor can prescribe precise dosages of the "correct"
>   drugs needed to overcome the effect of such unusual notions as  suggested
>   in  this  series of postings.  These drugs will assure that your opinions
>   conform comfortably to those currently accepted by  the  government,  and
>   will result in many opportunities for career advancement.

Did you know that fully _half_ of all babies are born within one week of a full
Moon!  No kidding.  Of course, if that surprises you or if you take allegations
of such things seriously, you really could use some help.

I wouldn't suggest drugs or mindwashing.  Just get your lazy behind down to
the library and start reading up on the explanations for all these "bizzare,
unexplained" phenomena.

--
Josh Hopkins                                          [e-mail]

"We can lick gravity, but the paperwork's a bit tougher."  Wernher von Braun

------------------------------

Date: 7 Nov 92 20:46:44 GMT
From: Spacelink <[e-mail]>
Subject: Space_nz. Information Service.
Newsgroups: sci.astro,sci.edu,sci.space,sci.space.shuttle

Space_nz is a Space Information Bureau based in New Zealand.  Our aim is
to supply answers to people's questions whether they be simple or complex
on the history of human accomplishments in space.

You can contact us through our Email address of [e-mail],
or by writing to Spacelink at PO Box 331402, Takapuna, Auckland 9, New Zealand,
(Please enclose an SASE), or by Fax on 64-9-8494282.

This is a free service for the curious, supplied by a team of voluntary
Spaceflight enthusiasts.

This Article is to put our Previous Posted Article right with regards to our
email address.
--
DOMAIN:  [e-mail]
SNAIL:   PO Box 331402, Takapuna, Auckland 9, New Zealand
FAX:     [phone]

------------------------------

Date: 7 Nov 92 23:22:03 GMT
From: "keith farmer;S10000" <[e-mail]>
Subject: Swift-Tuttle Comet a threat to earth?
Newsgroups: sci.astro,sci.space

Thanks to those who wrote to me about the typo... I don't use the name often.

Keith

------------------------------

Date: Sat, 7 Nov 1992 23:02:31 GMT
From: Paul Dietz <[e-mail]>
Subject: Ten embarrassed questions about the moon (very long)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Roberts) writes:

 (snarfy wrote:)

>-   into  the  surface  of  these dark, plain - like areas. Soil samples weer
>-   loaded with rare metals and elements like titanium,  zirconium,  yttruim,
>-   and  berylium. How the moon could have been formed by some random process
>-   with  such  high  concentrations  of  rare  elements   has   never   been
>-   satisfactorily explained.
>
>For chemical analysis, you're going to have to read some actual scientific
>papers (it won't show up in Time Magazine).

I suggest snarfy go read some books on geological processes.
In particular, read some books on how elements are segregated
due to chemical differences.  Also, he should go look up
how many different and interesting minerals have been found
-- *including* minerals high in titanium, beryllium, etc. etc.


>-   never been observed  on  the  moon)  that  the  high  readings  could  be
>-   explained   by  highly  radioactive  elements  just  under  the  surface.
>-   Actually, the amount of radioactive materials on the SURFACE of the  moon
>-   is  "embarrassingly  high"  .   Where  did  all  of this hot ,radioactive
>-   material ( uranium and thorium ) come from ? And  if  it  came  from  the
>-   interior  of  the  moon  (very  unlikely)  ,how  did it get to the moon's
>-   surface?
>
>
> The total lunar abundance of uranium is thought to be about 60 ppb,
> and thorium about 230 ppb. The only figure I could find for the Earth
> was 2.7 ppb in the crust. One might explain the difference by greater
> gravitational differentiation in the Earth, since it has greater
> gravity, and spent a much longer period of time molten. In other
> words, the Earth might have the same overall concentration, it's just
> more concentrated in the interior.

The figure you have for terrestrial uranium is wrong: uranium is
about 1000x more abundant than that in the earth's crust.

Both uranium and thorium are lithophiles.  That is, they do
*not* go to the molten metal core.  Note that on the molecular
level this differentiation has *nothing* to do with density;
it's driven by chemistry.  Uranium is enriched in granites
relative to basalts, btw (and granites, which make up most
of the mass of continents, are lighter than basalts).

Since the entire moon has been subjected to melting and
differentiation, it should not be surprising that elements
have been segregated, or that uranium and thorium are abundant
in the more felsic rocks of the lunar crust.  Moreover,
if the moon is derived from outer mantle and crustal material
from the earth that has been blown into space by a megaimpact,
it started out enriched in lithophiles.

BTW: snarfy mentioned the "capture" theory of the moon.  One thing
that destroys this idea is that the earth and the moon lie on the same
line in oxygen isotope plots (plot delta-O18/O16 vs. delta-O17/O16.)
This means they must come from a common source.  The other three
theories (fission, coaccretion and giant impact) get around this; the
first two of these are shot down for other reasons.

    Paul F. Dietz
    [e-mail]

------------------------------

Date: Sun, 8 Nov 1992 00:48:36 GMT
From: Henry Spencer <[e-mail]>
Subject: Ten embarrassed questions about the moon (very long)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Roberts) writes:
>Henry will probably sneer at the following, but I have long thought that the
>moon influences living things on the Earth, and the observations stated in
>the above reference are certainly remarkable coincidences, if they are just
>coincidence. However, I wouldn't make any claim of strange "psychic
>connections" - tidal and lighting cycles should be considered the main
>causes of any possible influence.

Careful statistical attempts to look for lunar effects over long periods
generally come up empty-handed.

However, it's not hard to understand how these tales get started.  For
one thing, lighting effects are indeed significant -- the rate of things
like burglaries really does vary with outdoor illumination.  For another,
the lunar cycle is sufficiently close to an exact number of weeks that
near-full moons often line up with weekends for several months in a row...
and all kinds of things, starting with alcohol consumption and proceeding
from there to automobile accidents and hospital admissions, show quite
strong 7-day cycles.  Finally, there is a well-known and well-understood
human tendency to remember the unusual and forget the mundane.  Yes, odd
things sometimes happen at the full moon... but to draw any meaningful
conclusions from this, you have to figure in the times when odd things
happened without a full moon, or the times when nothing noteworthy happened
during a full moon.  Coincidences do happen; to establish correlation, you
have to look at the non-coincidences too.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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End of Space Digest Volume 15 : Issue 396
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