HDTenEightyP/NetNews huggingface dataset:
From: pcl@ox.ac.uk (Paul C Leyland)
Newsgroups: sci.astro
Subject: Re: Cleaning mirrors
Date: 27 Jan 93 13:10:47 GMT
Organization: Oxford University Computing Services, 13 Banbury Rd Oxford OX2
	6NN
In-reply-to: rking@acorn.co.uk's message of 26 Jan 93 14:12:32 GMT

In article <21187@acorn.co.uk> rking@acorn.co.uk (Richard King) writes:


   Folks,

   What are the recommended methods for cleaning mirrors ?
   My 6" has a layer of dust which I can't shift with an aerosol
   air blower so I'm wondering what else I can do.

Here's what I do.

Blow off what you can.  Then rinse off as much as possible with a
gentle stream of water (no scrubbing!).  De-ionized is best, but
tapwater will do so long as you don't let your mirror dry before the
next step.

Now, use pure soap-flakes *completely* dissolved in warm de-ionised
water.  Fill up your concave mirror and gently swill around.  After a
couple of minutes, pour off and repeat.

Now that you've shifted most of the crap that is going to dissolve or
come loose without scrubbing, you fill up your mirror with warm soapy
water again and *very gently* drag a loose piece of cotton wool
radially over the surface from the center out to the rim.  Don't be
afraid to use several pieces (i.e. replace after every 3-4 wipes).
Pour out the water and repeat.  Don't let the mirror dry before the
next step

Now, wash off the soap well with clean warm de-ionized water, rinsing
at least twice.

Some people use pure ethanol or propanol as a final drying stage, but
if your water was clean and the rinsing was thorough, your mirror
should dry cleanly in a gentle stream of warm air.  I never bother
with the solvent.

It should be obvious that you've got to make the preparations in
advance.  You need a few squeezy bottles, filled with clean and soapy
water and labelled as such; you need to prepare a dozen or two cotton
wool swabs; you need a hair-dryer or similar to hand.  It's helpful to
have a waterproof wastebin nearby.  Warming the water will need a
*clean* pan and a stove and so on.  The important thing is that if you
don't do this lot before starting on the mirror, you are going to find
the process much more difficult.


This technique works a treat on my 18"

Paul

--
Paul Leyland <pcl@oxford.ac.uk>          | Hanging on in quiet desperation is
Oxford University Computing Service      |     the English way.
13 Banbury Road, Oxford, OX2 6NN, UK     | The time is come, the song is over.
Tel: +44-865-273200  Fax: +44-865-273275 | Thought I'd something more to say.
Finger pcl@black.ox.ac.uk for PGP key    |
From: beaucham@astro.phy.ulaval.ca (Dominique Beauchamp)
Newsgroups: sci.astro
Subject: Re: Need formulas to point unaligned telescope
Date: 21 Jan 93 14:06:09 GMT
Organization: Universite Laval, Ste-Foy, Qc, Canada

In article <C15s9C.oM@boi.hp.com> jmcvey@boi.hp.com ( John McVey         x3638 ) writes:
>Rather than the usual reference to a book, would some well informed
>person just post the formulas and how to use them.
>
>Thanks in advance,
>
>John McVey
>jmcvey@hpbslq.boi.hp.com

Listen, I cannot give here all the formulae!  But I can give you a good 
reference.  Look at Sky & Telescope for February 1989.  It is an article 
written by Toshimi Taki in the "Astronomical Computing" column.  He gives
us a little program in BASIC that allow a telescope to be aimed without any
polar alignment.  You just have to aim 2 references stars.  It works like
the little boxes with shaft encoders (I cannot remember the name).

But the article will give you all the formulae which are rather easy to
understand if it is all you want to know.

Hope it can help you!

	Dominique Beauchamp
Newsgroups: sci.astro
From: L629159@LMSC5.IS.LMSC.LOCKHEED.COM
Subject: Re: Refurbishing Observatory...SURPRISE !!
Organization: Lockheed Missiles & Space Company, Inc.
Date: Thu, 21 Jan 93 13:15:40 PST

I agree with previous posters regarding the value of this find. Wow!
People at Lick Observatory recently reground the objective of their
36 inch Alvan Clark refractor (a couple of years ago?)  You might
communicate with them.  In any case, do nothing in haste, you have
a great scope there.

Al Moore

Newsgroups: sci.astro
From: moroney@world.std.com (Michael Moroney)
Subject: Re: The Moon's Orbit (Re: Solar Eclipse Question)
Organization: The World Public Access UNIX, Brookline, MA
Date: Thu, 28 Jan 1993 03:23:51 GMT

tjt@Jpl.Nasa.Gov (Tim Thompson) writes:

>nailed to Jupiter's equatorial plane (likewise Saturn, etc.). Remember that the
>Moon's mass, expressed as a fraction of the parent planet's mass, is by far the
>largest in the solar system, which makes the Earth-Moon pair unique

Except for Pluto/Charon, of course.

-Mike
Newsgroups: sci.astro,sci.physics
From: andromed@Hail.ATM.Dal.Ca (Mike Boschat)
Subject: Perseid watch ? & meteorite.
Organization: ATM, Dalhousie University, Halifax, NS, Canada
Date: Mon, 25 Jan 1993 03:00:43 GMT

hello;

Are there any plans for a major Perseid meteor watch this august to 
determine if the stream has been replenished or  not.?
 Also with all the "technology" the military could not detect the
so-called meteorite that hit Coratia..if indeed one did then a nice
setup for saying it was a missle attack...has there been anymore on
this meteorite.?
                                        Clear skies

                                        Mike Boschat

 --------------------------------------------------------------------------
|    JOHN F. KENNEDY              | " Our problems are man-made, therefore |
|                                 |  they can be solved by man. "          |
|  ASTRONOMICAL  OBSERVATORY      |                                        |
|                                 |                      J.F.K.            |
 --------------------------------------------------------------------------
30th Anniversary of President John F.Kennedy assassination Nov.22,1963-1993 AD
Newsgroups: sci.astro
From: phfrom@nyx.uni-konstanz.de (Hartmut Frommert)
Subject: Re: Dark matter
Organization: Dept. of Physics, University of Constance
Date: Tue, 26 Jan 1993 14:02:20 GMT

ethanb@ptolemy.astro.washington.edu (Ethan Bradford) writes:

>The only recent news w.r.t. dark matter that I know of was the
>conclusion that there was a lot more dark matter than previously
>thought in a small (3 galaxy) cluster.  If the cluster is typical, the
>universe is definitely closed.  The evidence for the dark matter is
>still indirect; in this case it is necessary to confine the hot gas in
>the cluster.

Could someone post a reference ?
-
 Hartmut Frommert                 <phfrom@nyx.uni-konstanz.de>
 Dept of Physics, Univ of Constance, P.O.Box 55 60, D-W-7750 Konstanz, Germany
                                           -- Eat whale killers, not whales --
From: juliand@cogsci.ed.ac.uk (Julian Day)
Newsgroups: sci.astro
Subject: Re: New planet
Date: 28 Jan 93 11:43:56 GMT
Organization: Centre for Cognitive Science, Edinburgh, UK

In article <1993Jan25.092930.24684@ugle.unit.no> frodet@brosme.dhmolde.no (Frode Tennebo) writes:
>
>Astronomers at the 2.2-meter-telescope at Mauna Kea have recently
>discovered a new planet in the solarsystem, which ut to this time has been
>unknown. The planet, which has temporarily has been named 1992 QB1
>(where those astronomers get their names from beats me), is more than six
>billion kilometers (app. 5.56 light-hours) away and orbits slowly around
>the sun outside the orbit of Pluto.
>
>1992 QB1 is much smaller than Pluto, perhaps only 200 kilometers in
>diameter. Pluto has a diameter of 2400 km.


	What an exciting discovery! But is this really "planet number
	ten", or, if it is only 200 km across, does it count as an
	asteroid rather than a planet?





-- 
+	Julian Day 				juliand@cogsci.ed.ac.uk  +
+	Department of Cognitive Science,				 +
+	1-6 Buccleuch Place,			Tel. 031 650 1000	 +
+	EDINBURGH EH8 9LW 			extn. 4418		 +
Newsgroups: sci.astro
From: metares@well.sf.ca.us (Tom Van Flandern)
Subject: Re: Toutatis Captured by Radar Images
Organization: Whole Earth 'Lectronic Link
Date: Thu, 28 Jan 1993 16:01:29 GMT


bscott@lyman.pppl.gov (Bruce Scott) writes:

> Actually, one important reason why people turned against the exploding
> planet hypothesis was the discovery that certain classes of asteroids
> have compositions which are not consistent with any scenario which
> involves heating above 300 K.

     The most common type of meteorite, chondrules, are partially melted
rocks, where the melting occurred well before atmospheric entry.  It is
true that *certain* classes of meteorites have apparently never been hot.
But a planetary explosion would have vaporized core material, melted
intermediate material, and simply fractured the outer mantle and crust.
Meteorites from this last class would have been propelled far away before
they could be heated significantly (as Leigh Palmer also suggested).

> This and the fact that the property classes (achondrite, C1 and C2
> chondrite, enstatite, etc) are on isotopic grounds irreconciliable with
> any single parent body are the reasons J S Lewis argues against it.

     That argument has always seemed a bit of a non-sequitur to me.  If (in
the standard model) all the asteroids and meteorites had condensed into a
planet instead of going their separate ways, then the single parent planet
would have been isotopically diversified.  But chiefly, one must expect
that most isotopic anomalies originated in the intense irradiation event
that accompanied the explosion.  There is ample meteoritic evidence for
this irradiation event.

     One should also note that the exposure ages of meteorites neatly
define just the ways such materials would be layered in a planet.  For
example, the heavy iron meteorites came from farthest in, and have the
greatest "cosmic ray" exposure ages; and the lightest, most "primitive"
meteorites, presumably from near the planet's crust, have the smallest
exposure ages.

> A chemical explosion strong enough to break up a massive body? I've
> never seen a plausible scenario for this. I won't work out energy per
> gram versus self-gravity energy now, but it seems that the usual
> chemical explosive stuff is too weak for this (unless one had a pure
> liquid gasoline planet well-mixed with oxygen!).

     It all depends on the size of the hypothetical planet.  If it is to
be Saturn-sized, as Ovenden proposed, then no chemical-energy process is
sufficient to overcome self-gravitation.  -|Tom|-

-- 
Tom Van Flandern / Washington, DC / metares@well.sf.ca.us
Meta Research was founded to foster research into ideas not otherwise
supported because they conflict with mainstream theories in Astronomy.
Newsgroups: sci.astro
From: bcollins@utdallas.edu (ARLIN B COLLINS)
Subject: Re: Availability of "Explanatory Supplement"
Organization: Univ. of Texas at Dallas
Date: Sat, 23 Jan 1993 06:01:40 GMT

jbrown@stein.u.washington.edu (Jeffery Brown) writes:
>In article <727701137snz@chrism.demon.co.uk> chris@chrism.demon.co.uk writes:
>>Does anyone know if the long-awaited new edition of the "Explanatory
>>Supplement to the Astronomical Almanac" has been published yet?
>>
>It has, but it's now published commercially, not by the US Gov't Printing
>Office and H.M. Stationery Office.
>
>"Explanatory Supplement to the Astronomical Almanac", P. K. Seidelmann, ed.
>1992   Published by University Science Books.  ISBN 0-935702-68-7 (that's
>hardbound; I don't know if it's available in softcover).  I got mine back
>in September or so, having ordered it in advance.  Unfortunately, I've 
>forgotten what it cost me; I think it was in the $50 (+/- $15) range, and
>I know I got a discount by ordering it early.
>---
 here's a little more info:
     University Science Books
     20 Edgehill Road
     Mill Valley, CA  94941
     FAX: 415/383-3167

     750 pages, hardcover

 I got mine from  Science Book Club  (same basic company as Astro-book-club)
     order #47160
     retail:  $65.
     member:  $45.
     'bonus'  $30.    (after you accumulate a "bonus" credit)

     so, sign-up with Astro-book club, get the basic package,
     and one of your  '4'  books can be this one....
     whatever,  enjoy.

---I am not affiliated with  these book clubs,
   just a happy customer for a few years.

-- 
 Arlin B Collins    Fri 22 Jan   Sun   Civil  Naut   Astro
 bcollins@utdallas.edu   rise:  07:28  07:02  06:32  06:02
 lat N32.9 long W096.9    set:  17:50  18:17  18:47  19:16
Newsgroups: sci.astro
From: jrbd@craycos.com (James Davies)
Newsgroups: sci.astro
Subject: Re: THE DIVINE MASTERS OF THE UNIVERSE
Date: 26 Jan 93 20:31:36 GMT
Organization: Cray Computer Corporation

In article <1k3eljINN93@transfer.stratus.com> somebody@somehost.edu writes:
>In article <1993Jan25.173130.3296@cnsvax.uwec.edu>, mcelwre@cnsvax.uwec.edu writes:
>> Although the following article is on the subject of religious studies, it
>> illustrates some important facts about the Universe:
>                             ^^^^^?
>
>He's BAAAAaaaack (and wouldn't know a fact if it bit him on the butt)!
>
>>                                            Robert E. McElwaine
>>                                            2nd Initiate in Eckankar
>
>Ah, well at least he's not claiming to be a scientist this time.
>Flame away, Bobby, I'll give your responses all the attention they
>deserve (and I've been *far* too generous already).

...and, Robert, get your caps-lock key fixed, ok?  It's annoying when
somebody CAPITALIZES every OTHER word, it MAKES you LOOK like a PINHEAD!!
From: br0w+@andrew.cmu.edu (Bruno W. Repetto)
Newsgroups: sci.astro
Subject: Re: THE DIVINE MASTERS OF THE UNIVERSE
Date: 26 Jan 93 12:58:19 GMT
Article-I.D.: andrew.UfNQ8=u00WB_E9XrdU
Organization: Doctoral student, Industrial Administration, Carnegie Mellon, Pittsburgh, PA

Excerpts from netnews.sci.astro: 25-Jan-93 THE DIVINE MASTERS OF THE U..
by mcelwre@cnsvax.uwec.edu 
> From: mcelwre@cnsvax.uwec.edu
> Subject: THE DIVINE MASTERS OF THE UNIVERSE
> Date: 25 Jan 93 17:31:30 -0600
>  
>  
>  
>      Although the following article is on the subject of religious
studies, it
> illustrates some important facts about the Universe:

Yeah, sure!

I WONDER what A*ian would SAY about this.  Furthermore, I WONDER
what the CRACKPOT INDEX would be for this DRIVEL...

sci.astro INQUIRING minds want to KNOW!

Bruno.  br0w+@andrew.cmu.edu
Newsgroups: sci.astro,sci.space,comp.infosystems.wais
From: kjenks@gothamcity.jsc.nasa.gov
Subject: Re: Hewlett Packard conin space
Originator: kjenks@gothamcity
Keywords: bogus
Organization: NASA/JSC/GM2, Space Shuttle Program Office
Date: Sat, 23 Jan 1993 02:16:53 GMT

>In article <1993Jan21.184138.22352@aio.jsc.nasa.gov>, I, 
  kjenks@gothamcity.jsc.nasa.gov, wrote:

>>Before you ask, the SPOC software is NOT available to the general
>>public.  It includes a world map showing day/night and the current
>>position of the Orbiter, updated in real time. 

In article <1jp4agINNlim@mojo.eng.umd.edu> sysmgr@king.eng.umd.edu writes:
>Like, bogus.  Do you realize how much money NASA could make by selling
>it off to Space Junkies at $50 a pop? :)

Bogus, indeed.  It's hard to get this straight, sometimes.  NASA is NOT
in the business of making money.  (That's the Treasury's job; they
print the stuff.)

But this is sympomatic of a larger problem: NASA can't release software
it creates to the public domain.  Whatever software NASA creates is in
the Government's domain, and may eventually be released through
COSMIC.  

So I can't post the source code to our latest nifty improvement on
WAIS, the Wide Area Information Servers out for anonymous FTP, where I
think it belongs.  (Besides, we're still in alpha testing.)  We have
some top people working on this software distribution issue, but many
of the decision makers at NASA still think computers are big old things
which take up large rooms and dozens of people to operate.  Now they
only take up small rooms and dozens of people.

-- Ken Jenks, NASA/JSC/GM2, Space Shuttle Program Office
      kjenks@gothamcity.jsc.nasa.gov  (713) 483-4368

     "We at NASA develop cutting-edge technology for our aeronautics and
      space programs.  We view technology transfer as a way of life.  
      It's one of our top priorities." -- Daniel S. Goldin, NASA Administrator

Yeah, right.
Newsgroups: sci.astro
From: apryan@vax1.tcd.ie
Subject: Perseid watch 1993 announcement
Organization: Trinity College Dublin
Date: Tue, 26 Jan 1993 21:14:02 GMT

Major Perseid Watch

Astronomy Ireland is planning a major watch for the Perseids this year.
Last year, over 14,000 people attended our Perseid watch in the Phoenix
Park, Dublin (dispite the rain!). Ireland is ideally placed to observe
this year's Perseids, which is expected to be the most active yet, as
the parent comet returned as predicted at the end of 1992. Our latest
calculations show that the maximum of the shower will be visible in
Ireland close to the zenith.

The watch is beind held in the grounds of Birr Castle, home of the
Rosse telescope which was the world's largest telescope for over a quarter
of a centuary from 1845 to 1914. We are involved in the project to restore
this world-famous part of Ireland's rich astronomical heritage, which will
be the largest telescope in Europe when restored. It will be ideal for
visual observations.

Astronomy Ireland is the largest astronomy and space interest group in
Ireland, with over 1,000 members and growing all the time. We are always
looking for new members, especially beginners. We hold regular lecture
meetings, observing sessions and publish a bi-monthly magazine aimed at
beginners and experienced observers alike. We now have members in every
county in Ireland, and a number in the UK also.

We have arranged for Patrick Moore to give a public lecture in Dublin on
Saturday March 13.

Tony Ryan, Hon. Secretary, Astronomy Ireland, P.O. Box 2888, Dublin 1, Ireland.
From: denisf@ersys.edmonton.ab.ca (Denis Fafard)
Newsgroups: sci.astro
Subject: Re: Vacuum Question
Date: Fri, 22 Jan 93 14:24:35 MST
Organization: Edmonton Remote Systems #3, Edmonton, AB, Canada

cre1@ns1.cc.lehigh.edu (CHRISTOPHER R. EMERSON) writes:

- 
- Here's a question about space I've had for quite some time, hopefully one of
- you has more insight than I:
- 
- If you were suddenly to find yourself floating in space (no pressure suit),
- what would happen to your body?  Would (as some people say) you simply blow
- up? (inside pressure>>outside pressure) or would you just suffocate and
- freeze?
- 
  I believe that this topic was covered in the star.trek.tech group. From
 what I read (and this is just a brief summary) the eventual conclusion
 reached was that you would NOT explode.  I vaguely remember something
 about you being able to survive for a short period of time, (matter of
 seconds) then the body having some affects from the cold and death.
  That, all under 20 seconds or so ??  Perhaps scan back thru the posts
 and see if it is still there.  

 (actually, could have been here that I read it!)

--
Denis Fafard              denisf@ersys.edmonton.ab.ca 
Newsgroups: sci.astro
From: dsc@gemini.gsfc.nasa.gov (Doug S. Caprette Bldg. 28 W191 x3892)
Subject: Re: Comments from MEADE about SCT's
Organization: CDP VLBI
Date: Fri, 22 Jan 1993 17:46:28 GMT




In article <93021.031222LABBEY@GITVM1.BITNET> <LABBEY@GITVM1.BITNET> writes:
>Re-coating a lens will improve its light transmission, and nothing else.
>It will NOT improve performance on the planets.
>
>Furthermore, it is a dangerous process, involving high temperatures.  There is
>some danger that the lens will break. 

Or, it may distort the corrector, changing its figure.   I understand that in
quality refractors, it was (maybe still is) the practice to leave the last
surface uncoated, and tweak the correction by refiguring the last surface
after the other three were coated.

>                                        Besides, the price you mentioned
>is a considerable percentage of the price of a new scope.
>
>Forget re-coating.  What you see on planets is mainly determined by the
>number of hours you spend at the eyepiece.  Join the ALPO and make sketches.

I think you missed the part about the corrector being covered with sleeks.
This would indeed be expected to degrade the resolution.

Moral of the story:
Don't clean your optics until they are absolutely filthy.  Less crudely put,
an ounce of prevention is worth a pound of cure--keep your optics from get-
ting dirty as much as possible so that you very seldom need to clean them.

>In two years you will be up there with the best of them.
>
>Oh yes, one other suggestion for viewing planets.  Buy an f/8 Newtonian.
>

Or longer.

--
dsc@gemini.gsfc.nasa.gov  
 |  Regards,         |   Hughes STX                |    Code 926.9 GSFC        |
 |  Doug Caprette    |   Lanham, Maryland          |    Greenbelt, MD  20771   |
 -------------------------------------------------------------------------------
"...when the Saudis agreed to ask for American assistance.."
				  -- Dick Cheney 2/21/91
From: paul.burnett@pcs.sj.ca.us (Paul Burnett) 
Newsgroups: sci.astro
Subject: Re: averting doom
Date: 22 Jan 93 18:20:00 GMT
Distribution: world
Organization: PCS-BBS - San Jose, CA - 408-270-4085
Reply-To: paul.burnett@pcs.sj.ca.us (Paul Burnett) 

TO: mrw9e@kelvin.seas.Virginia.EDU

   >>]>Hi there. As I recall, in about a billion years the sun will have
   >>]>about twice the luminosity it presently has.

MRW>Actually, for solar-sail proponents like myself, that's prime sailing
   >weather!

Or, as we say here on the Left Coast, "Surf's Up!"  <G>
---
 . QMPro 1.0 41-8688 . ...from San Jose, CA
                                                                                                                                                              
Newsgroups: sci.astro
From: awootten@slacktide.cv.nrao.edu (Al Wootten)
Subject: Re: Tycho Biography (was Re: Tycho Apocrypha)
Organization: nrao
	<1jlm17INNs34@gap.caltech.edu> <1993Jan21.112709.1@fnalf.fnal.gov>
Date: Thu, 21 Jan 1993 20:12:59 GMT

The Thoren biography is excellent.  I once spent the better part of two
days in Copenhagen trying to figure out how to get to Hven without success.
I learned one should leave from Sweden.  Thoren mentions plans to reconstruct
Uraniborg...anyone know anything more on that subject?

--
+--------------------------------------------__---------+
| Alwyn  Wootten  (awootten@nrao.edu) 	     \/	GBT	|
| National Radio Astronomy Observatory        ^         |
| 520 Edgemont Road, Charlottesville, VA 22903-2475, USA|
| (804)-296-0329 voice  Let's build The Millimeter Array|
| (804)-296-0278 FAX           {>    {>    {>    {>     |
+------------------------------^-----^-----^-----^------+
From: bscott@lyman.pppl.gov (Bruce Scott)
Newsgroups: sci.astro
Subject: Re: Toutatis Captured by Radar Images
Date: 25 Jan 93 22:15:09 GMT
Reply-To: bscott@lyman.UUCP (Bruce Scott)
Organization: Princeton University, Plasma Physics Laboratory

palmer@sfu.ca (Leigh Palmer) writes:

>I think the most persuasive arguments against the exploded (or collided)
>planet hypothesis were aesthetic rather than scientific. Catastrophism
>was "out" for a while, probably because of distaste engendered by one of
>its proponents (Velikovsky). Luis Alvarez put catastrophism back into
>favor with his identification of the K-T boundary mechanism, and it is,
>perhaps, timely for the exploded planet hypothesis to reemerge into a
>more sypathetic community.

Actually, one important reason why people turned against the exploding
planet hypothesis was the discovery that certain classes of asteroids have
compositions which are not consistent with any scenario which involves
heating above 300 K. This and the fact that the property classes
(achondrite, C1 and C2 chondrite, enstatite, etc) are on isotopic grounds
irreconciliable with any single parent body are the reasons J S Lewis
argues against it.

The best review I know of is where I got this:

J S Lewis and R G Prinn, Planets and their Atmospheres: Origin and
Evolution, Academic Press, 1984.
-- 
Gruss,
Dr Bruce Scott                             The deadliest bullshit is
Max-Planck-Institut fuer Plasmaphysik       odorless and transparent
bds at spl6n1.aug.ipp-garching.mpg.de                 -- W Gibson
Newsgroups: sci.astro