Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V16_5/V16NO502.ZIP/V16NO502

Internet Message Format | 1993-07-13 | 28KB

Date: Sat,  1 May 93 05:00:02
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #502
To: Space Digest Readers
Precedence: bulk


Space Digest                Sat,  1 May 93       Volume 16 : Issue 502

Today's Topics:
                              big THANKS
          Command Loss Timer (Re: Galileo Update - 04/22/93)
                 Gamma Ray Bursters. WHere are they.
                 Gamma Ray Bursters. Where are they?
         HST Servicing Mission Scheduled for 11 Days (2 msgs)
Interstellar T _is_ 3-4K; notes on Pluto/Charon talk and Pluto Mission
                  Long term Human Missions (2 msgs)
                   Mars Observer Update - 04/28/93
                 temperature of the dark sky (2 msgs)
                           Transistor/tube
                         Tsniimach Enterprise
                   U.K.: see Mir in evening skies!
            U.K.: See Mir in Evening skies - tell friends!

    Welcome to the Space Digest!!  Please send your messages to
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----------------------------------------------------------------------

Date: Fri 30 Apr 93 14:19:24-EST
From: [e-mail]
Subject: big THANKS

I'd like to thank everyone and anyone who sent me information
to help me with my project.



_______  ___   ___       ___      ___     ___  ___    ___
|     |  |  |  |  |     /   \     |   \   |  | \  \  /   /
--| |-   |  |  |  |    / /\  \    | |\ \  |  |  \  \/   /
  | |    |   --   |   /  --   \   | | \ \ |  |   \     /
  | |    |   __   |  /  -----  \  | |  \ \|  |   /  /\ \
  |_|    |__|  |__| /__/     \__\ |_|   \____|  /__/  \_\



I'll send my report to all who requested a copy!


  KEITH MALINOWSKI [e-mail]
  Stockton State College
  Pomona, NJ 08240

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

Date: Wed, 28 Apr 1993 19:18:00 GMT
From: David Ward <[e-mail]>
Subject: Command Loss Timer (Re: Galileo Update - 04/22/93)
Newsgroups: sci.space,sci.astro,alt.sci.planetary

In article <[e-mail]>, [e-mail] (Jim Cobban) writes...
>Having read in the past about the fail-safe mechanisms on spacecraft, I had
>assumed that the Command Loss Timer had that sort of function.  However I
>always find disturbing the oxymoron of a "NO-OP" command that does something.
>If the command changes the behavior or status of the spacecraft it is not
>a "NO-OP" command.
>
I know its semantics, but the "no-op" _doesn't_ do anything.  The
Command Loss Timer is simply looking for a command, any command.  A
"no-op" is simply a spacecraft command that drops bits into the big
bit bucket in the sky.  "No-op" also get used as timekeepers to provide
millisecond delays between command sequences (used on the thruster preps
on GRO, er, Compton) and to verify command links at the beginning of
TDRS events.  All in all, a rather useful command.  And, an intelligent
FDC test on Galileo (the Command Loss Timer).

David W. @ GSFC
(still looking for GRO data, even though I'm the wrong David)

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

Date: 28 Apr 93 15:07:43
From: Steinn Sigurdsson <[e-mail]>
Subject: Gamma Ray Bursters. WHere are they.
Newsgroups: sci.astro,sci.space

In article <[e-mail]> [e-mail] (Ethan Bradford) writes:

   In article <[e-mail]> [e-mail] (Steinn Sigurdsson) writes:

      _The_ problem with Oort cloud sources is that absolutely
      no plausible mechanism has been proposed. It would have
      to involve new physics as far as I can tell. Closest to
      "conventional" Oort sources is a model of B-field pinching
      by comets, it's got too many holes in it to count, but at
      least it was a good try...

   So you have a plausible model for GRB's at astronomical distances?

I don't have any plausible models for GRBs at any distances ;-)

   Recent observations have just about ruled out the merging neutron star
   hypothesis, which had a lot of problems, anyhow.  We have to look for
   implausible models and what is fundamentally allowed independent of
   models.

Hmm, the "superbowl" burst has been claimed in press releases
to cast doubt on the merging NS hypothesis, from what I've read
(and I haven't seen the papers, only the press) I'd say it is
consistent with some of the merging NS models

   A paper on the possibility of GRB's in the Oort cloud just came
   through the astrophysics abstract service.  To get a copy of this

   Here is the abstract of that paper.

 ...
      indicator to these events all possible sources which are
      isotropically distributed should remain under consideration. This is
      why the Oort cloud of comets is kept on the list,
      although there is no known mechanism for generating \GRBs
      from cometary nuclei. Unlikely as it may seem, the possibility that \GRBs
      originate in the solar cometary cloud
      cannot be excluded until it is disproved.

This does not propose a _mechanism_ for GRBs in the Oort (and, no,
anti-matter annihilation does not fit the spectra at least as far
as I understand annihilation spectra...). Big difference.
That's ignoring the question of how you fit a distribution
to the Oort distribution when the Oort distribution is not well
known - in particular comet aphelia (which are not well known)
are not a good measure of the Oort cloud distribution...


*  Steinn Sigurdsson               Lick Observatory          *
*  [e-mail]        "standard disclaimer"      *
*  The laws of gravity are very,very strict            *
*  And you're just bending them for your own benefit - B.B. 1988*

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

Date: 28 Apr 1993 23:16:42 GMT
From: "Patrick C. Mock" <[e-mail]>
Subject: Gamma Ray Bursters. Where are they?
Newsgroups: sci.space,sci.astro

In article <[e-mail]>, [e-mail] (Kevin W. Plaxco) writes:
> In article <[e-mail]> [e-mail] (David Ward) writes:
>
> But I believe that there is a fundamental difference here.  The other x
> three instruments are focusing instruments, that, more or less, form
> an image, so positional errors are limited by craft attitude and the
> resolving power of the optics.  BATSE is an altogether different
> beast, effectively just 8 coincidence counters, one on each corner of
> the craft.  Positional information is triangulated from the
> differential signal arrival times at each of the detectors.

This is not quite right.  The differential arrival time techinique
requires interplanetary baselines to get good positions.  The
differential arrival at the eight detectors differ by 10's of nanoseconds.
This is smaller than BATSE's microsecond timing capabilities.
BATSE, Ulysses, and Mars Obsverver are used for this technique.

Each BATSE detector does not have a full sky field of view.
The sensitivity of each detector decreases with increasing
angle of incidence.  The burst position on the sky is determined by
comparing the count rates in different detectors.

Pat

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

Date: Wed, 28 Apr 1993 19:57:00 GMT
From: David Ward <[e-mail]>
Subject: HST Servicing Mission Scheduled for 11 Days
Newsgroups: sci.space,sci.space.shuttle,sci.astro

In article <[e-mail]>, [e-mail] (Bruce Scott) writes...
>If re-boosting the HST by carrying it with a shuttle would not damage it,
>then why couldn't HST be brought back to earth and the repair job done
>here?
>
>Is it because two shuttle flights would be required, adding to the alredy
>horrendous expense?
>

I don't think a reboost exercise is analogous to a shuttle landing/launch
in terms of stresses/misalignments/etc.  I would think of the reboost as
a gentile push, where a landing, then launch as two JOLTS which would
put more mechanical stress on the instruments.  Additionally, there might
be a concern about landing loads to the shuttle in the event of a laden
landing.  Finally, probably some thought went into possible contamination
problems if the instruments came back to earth.

Of course, the cost of two shuttle launches _is_ a good reason to avoid
something that might be done in one shuttle launch.  Here's hoping
Cepi's gang gets the job done right the first time.

David W. @ GSFC
(I used to work for Frank Cepollina)

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

Date: Wed, 28 Apr 1993 22:50:28 GMT
From: "Gary Morris @ignite" <[e-mail]>
Subject: HST Servicing Mission Scheduled for 11 Days
Newsgroups: sci.space,sci.space.shuttle,sci.astro

In <[e-mail]> [e-mail] (Brian Day) writes:
>[e-mail] (Rob Douglas) writes:
>>[...]  But try to land a shuttle with that big huge telescope in the
>>back and you could have problems.  The shuttle just isn't designed to land
>>with that much weight in the payload.

>Is HST really _that_ much heavier than a Spacelab ???

HST is about 25,500 lbs (11,600 kg).  That doesn't include the cradle that
would have been in the cargo bay when it was deployed.  Spacelab-J on STS-47
was 21,861 lbs (according to the press-kit).

As someone else pointed out if they had been unable to deploy it for some
reason that would have had to land with it still in the cargo bay and this
was a planned for contingency.  This is not a problem for the shuttle,
though it would eliminate KSC as a landing site, they still have to go to
Edwards when landing with something like Spacelab in the cargo bay.

--GaryM
--
Gary Morris                      Internet: [e-mail]
TeleUSE Development              UUCP:     uunet!alsys.com!garym
Alsys Group (TeleSoft)           Phone:    [phone] x128
San Diego, CA, USA               Fax:      [phone]

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

Date: Wed, 28 Apr 1993 14:57:08 GMT
From: Stupendous Man <[e-mail]>
Subject: Interstellar T _is_ 3-4K; notes on Pluto/Charon talk and Pluto Mission
Newsgroups: sci.astro,sci.space

   (sci.space readers can skip the first paragraph)

  Yesterday, in response to Henry Spencer's question about the
temperature of a blackbody in interstellar space, I said "Dust grains
acts as blackbodies, and they're at 40-150 K."  Well, I was dead
wrong.  Our local interstellar dust expert, Bruce Draine, has
informed me that dust grains _aren't_ good radiators in the far IR,
which is why they are so warm; actually, the ambient radiation field
from distant stars can bring a true blackbody to only 3 or 4 Kelvin.
Sorry, Henry, and anyone else I misled.  Obviously, time for me to
take another ISM class :-(

  In other news, Alan Stern of the Southwest Research Institute gave
a talk on the Pluto-Charon binary system yesterday.  He gave a brief
overview of the currently-accepted system parameters (volume ratio of
about 8:1, mass ratio about 15:1 or so, plus lots more...) and then
gave his thoughts on the formation of Pluto-Charon.  His idea is
that there were lots and lots of small planetesimals in the outer
solar system, with masses distributed as a power law of some kind;
over time, the planetesimals accreted into larger bodies.  Most got
scattered out of the solar system by close encounters with Jupiter
and Saturn, but many accreted into the gas giants, especially
Uranus and Neptune.  A large planetesimal was captured by Neptune -
we call it Triton [captured how?  Perhaps by a collision with a smaller,
already-existing Neptunian moon, perhaps by a very close passage through
Neptune's atmosphere - mondo aerobraking!].

  He notes that the two recently discovered "Kuiper Belt" objects,
1992 QB1 and 1993 FW, plus Chiron and Pholus, are all about the same
mass, and he identifies this group as one-accretion-down from the
larger bodies of Triton and Pluto/Charon.  Pluto/Charon, he thinks,
formed when an impacting body hit proto-Pluto, knocking some material
into a ring around Pluto which later accreted in Charon; similar to
ideas about the formation of Earth's moon.  There is good evidence
from spectra that the surfaces of Pluto and Charon are very different
(Pluto has methane frost, Charon doesn't), which can be used as evidence
for the impact theory.

  He believes that there may be around 1000 Pluto-to-Chiron-sized objects
remaining in a relatively stable dynamical zone just outside Neptune's
orbit, beyond 35 AU or so.  1992 QB1 and 1993 FW are the first members
of this population to be found, in his model.  Note that such bodies
will be very dark, since if their surfaces are covered with methane
frost, it will have photolyzed into very dark, long-chain hydrocarbons
by now.  The reason that Pluto has such a high albedo (around 0.5, I think)
is that its surface warms up JUST enough around perihelion to sublimate,
and when the atmosphere freezes out again, thirty years later, it forms
bright, new frost.  So any bodies much farther away than 30 AU are going
to be very hard to see.

  I hope I haven't made any errors in the transcription; if you see
a howling mistake, it's undoubtedly mine, not his.

  By the way, he's one of the top guns behind the Pluto Fast Flyby
mission (I think), and said that the current plans are to use a
Titan 4 to send the probe on "just about a rectilinear trajectory"
to Pluto (we were speaking loosely at the time...).  He'd like
to use a Proton, which gives a slightly smaller velocity but costs
MUCH less.  His figures: $500 Million for 2 Titan 4 launches (there
will be two separate probes, launched separately), or $120 Million
for 2 Proton launches.  He told a story about how the Soviets originally
offered to sell Proton launches for $30 Million each, but were forced
to increase their prices in the US in order to be allowed in the
marketplace.

  I'm just telling you what he said.

                          Michael

--
-----                                                    Michael Richmond
"This is the heart that broke my finger."    [e-mail]

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

Date: Thu, 29 Apr 1993 00:46:46 GMT
From: Alejo Hausner <[e-mail]>
Subject: Long term Human Missions
Newsgroups: sci.space,sci.space.shuttle,sci.astro

In article <[e-mail]> rek@siss81 (Robert Kaye) writes:
>
>Just a few contributions from the space program to "regular" society:
>
>1.    Calculators
>2.    Teflon (So your eggs don't stick in the pan)

Sorry to split hairs, but I just read in "The making of the atomic
bomb"(*) that teflon was developed during world war 2.  A sealant was
needed for the tubing in which uranium hexafluoride passed as it was
gradually enriched by difussion.  UF6 is very corrosive, and some very
inert yet flexible material was needed for the seals.

>3.    Pacemakers (Kept my grandfather alive from 1976 until 1988)

Alejo Hausner ([e-mail])

(*) Richard Rhodes, "The making of the atomic bomb", Simon and

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

Date: Thu, 29 Apr 1993 01:49:36 GMT
From: "Rob Shearman Jr." <[e-mail]>
Subject: Long term Human Missions
Newsgroups: sci.space,sci.space.shuttle,sci.astro

Excerpt From: rek@siss81 (Robert Kaye)

:Just a few contributions from the space program to "regular" society:
:
:1.    Calculators
:2.    Teflon (So your eggs don't stick in the pan)
:3.    Pacemakers (Kept my grandfather alive from 1976 until 1988)

                    Don't forget Tang!  ::smile::

 -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-
    Robert M. Shearman, Jr.  University of Maryland, College Park, Maryland
            E-Mail: [e-mail]   "WILL WORK FOR CHOCOLATE"
 -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-

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

Date: 28 Apr 1993 22:49 UT
From: Ron Baalke <[e-mail]>
Subject: Mars Observer Update - 04/28/93
Newsgroups: sci.space,sci.astro,alt.sci.planetary

Forwarded from the Mars Observer Project

                     MARS OBSERVER STATUS REPORT
                           April 28, 1993
                            12:40 PM PDT

Flight Sequence C9 is active as of 00:11 AM, Tuesday, April 27.  With
activities beginning at shortly before 5:00 AM yesterday, C9 commanded
the spacecraft to execute a series of slews and rolls to provide the MAG
(Magnetometer) Team data points in varying spacecraft attitudes and
orientations for the purpose of better characterizing the
spacecraft-generated magnetic field and its effect on their instrument.

The spacecraft was commanded back to Sun Star Init state at 9:07 AM to
re-establish Inertial Reference.  Transition back to Array Normal Spin
began at 11:17 AM, after which the sequence powered on the on-board
transmitter at 11:18 AM.  Telemetry reacquisition occurred at
approximately 11:30 AM at the 4 KBS Science and Engineering downlink
data rate on the High Gain Antenna.  Subsystem engineers report that all
systems appear to be nominal.  The command to terminate using the Low
Gain Antenna for uplink was sent at 12:31 PM.  Uplink and Downlink are
currently via the HGA.

MAG Calibration data has been recorded on Digital Tape Recorders 2 and 3.
Playback of DTR 2 is scheduled to take place tomorrow morning between
8:11 AM and 12:42 PM.  Playback of DTR 3 is scheduled to take place
tomorrow evening beginning at 11:57 PM and ending at 4:28 AM on Friday.
DTR playback will be performed via the High Gain Antenna at 42,667 bits
per second.  Upon verification of successful DTR playbacks, downlink will
be maintained at the 4K S & E rate.

The MAG Cal activity timeline ends at shortly before 5:00 AM on Friday
morning.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | The aweto from New Zealand
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | is part caterpillar and
|_____|/  |_|/       |_____|/                     | part vegetable.

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

Date: Wed, 28 Apr 1993 18:52:06 GMT
From: julie moses <[e-mail]>
Subject: temperature of the dark sky
Newsgroups: sci.astro,sci.space

>> Does anyone have a reference (something I can look up, not just your own
>> recollections -- I have a few of those myself) on the temperature of the
>> (night) sky as seen from space?
>>
>> Note, I am *not* talking about the temperature of the Microwave Background
>> Radiation.  There are more things in the sky than just the MBR; what I'm
>> after is total blackbody temperature -- what a thermal radiator would see,
>> disregarding (or shielding against) the Sun and nearby large warm objects.
>
>
I'm not sure if this will help you, but the (local) interstellar
radiation field has been measured and modeled by various groups.  If I
remember things correctly, the models involved contributions from three
different BB sources, so there's no obvious "temperature" of background
radiation in our local area.  However, the following references give the
interstellar radiation density as a function of wavelength, and you can
integrate and average in an appropriate manner to get an "effective"
temperature if you like:

Witt and Johnson (1973) Astrophys. J. 181, 363 - 368
Henry et al. (1980) Astrophys. J. 239, 859 - 866
Mathis et al. (1983) Astron. Astrophys. 128, 212 - 229

As you can see, the references are out of date, but they might get you
started.

Hope this helps,

                    Julie

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

Date: Thu, 29 Apr 1993 02:03:22 GMT
From: Henry Spencer <[e-mail]>
Subject: temperature of the dark sky
Newsgroups: sci.astro,sci.space

In article <[e-mail]> [e-mail] (julie moses) writes:
>...radiation field has been measured and modeled by various groups.  If I
>remember things correctly, the models involved contributions from three
>different BB sources, so there's no obvious "temperature" of background
>radiation in our local area...

Indeed, the sky doesn't look much like a black body if you look carefully
enough; in particular, its temperature at radio frequencies is quite a
bit higher than you would see from a black body.  Morgan&Gordon's fat
"Communications Satellite Handbook" has a graph of sky temperature vs.
wavelength, in fact, for communications design.

However, in terms of energy content, the RF frequencies are negligible.
For thermal purposes, at very large distances from the Sun the sky
looks like a black body at 3.5K (Allen, "Astrophysical Quantities").
I haven't found a number for non-large distances, since solar radiation
tends to be something you can't just ignore :-), but M&G says "about 4K"
in a brief discussion of why solar radiation dominates the problem.
--
SVR4 resembles a high-speed collision   | Henry Spencer @ U of Toronto Zoology
between SVR3 and SunOS.    - Dick Dunn  |  [e-mail]  utzoo!henry

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

Date: Fri, 30 Apr 93 13:46:10 EDT
From: Tom <[e-mail]>
Subject: Transistor/tube

>|Also, ask any electric-guitar enthusiast which type of amp they prefer, and
>|they'll tell you tube-type, since tubes have lower distortion and noise
>|than transistors.  'Course, most of your electric guitar types just say
>>"Tubes sound better, dude." :-)

>Of course,  they then  turn up the REverb, the Gain,  add in the analog
>delay line  and the Fuzz box.  I'd think they wouldn't notice the
>distortion.   Oh I forgot the phase shifters.

It is kind of absurd, isn't it?  Some players even want more distortion,
especially the Hendrix fans :-)  But there are a lot of them out there
that can only afford the amp, or who like playing music without distortion.
Then there are your hard-core Hendirx fans that want particular *types*
of distortion, i.e., they make it, not their amps.

>>Also, transistors have the advantage in both waste-heat and energy-use,
>>mainly because of the heaters on the cathodes of the tubes.

>Ah,  but how do they compare to Mechanical systems :-)

I didn't see a thing about waste-heat from Babbage, and haven't seen one
of those mechanical TV's in a while, so it's anybodie's guess :-)

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams 517-355-2178 wk   \ They communicated with the communists,
[e-mail] 336-9591 hm \ and pacified the pacifists. -TimBuk3
-------------------------------------------------------------------------

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

Date: Wed, 28 Apr 1993 23:01:38 GMT
From: Dennis Newkirk <[e-mail]>
Subject: Tsniimach Enterprise
Newsgroups: sci.space

In article <[e-mail]> [e-mail] ("F.Baube[tm]") writes:
>From: [e-mail]
>>
>> Tsniimach Enterprise is described as a ex-military
>> establishment, focusing on aerodynamics and thermal protection
>> of spacecraft and which has participated in the development of
>> the Buran shuttle system,  They are located near the NPO Energia
>> facility in Kaliningrad, outside of Moscow.
>
>If this facility is in Kaliningrad, this is not near Moscow,

Correction, and some more info: The Kaliningrad that Mr. Larrison
writes about is indeed near Moscow. I've read that it may also be known by
the name Podlipk, and is a short distance from Zvezdny Gorodok (Star
City) and the Cosmonaut Training Center there. I read that the Tsniimach
(Central Scientific Research Institute of Machine Building, est. 1961)
Enterprise was also responsible for creating the NKIK (Ground Command and
Measurement Complex) including the Kaliningrad Flight Control Center
which has controlled all Soviet/Russian manned spaceflights since its
completion in 1973. However, it appears to have been a part of the
Ministry of General Machine Building which was not part of the military
(Ministry of Defense) but would have been a part of the military-industrial
complex.

Dennis Newkirk ([e-mail])
Motorola, Land Mobile Products Sector
Schaumburg, IL

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

Date: Thu, 29 Apr 1993 01:47:15 GMT
From: [e-mail]
Subject: U.K.: see Mir in evening skies!
Newsgroups: sci.space,sci.astro

Astronomy & Space magazine's UK telephone newsline carries the times to
see the Russian Space Station Mir which will be visible every EVENING (some
time between 9 o'clock and midnight) from April 27 to May 7. It's about as
bright as Jupiter at its best. There are two cosmonuats on board.

For the time to watch, tel. [phone] (48p/min peak 36p/min all other
times, but prediction is at start of the weekly message so it only costs a
few pence).

E-mail reports of sightings would be appreciated: give lat/long and UT (a
few seconds accuracy if possible) when it passes ABOVE or BELOW any bright
star (say brighter than mag. 3), planet or Moon.

With Moon in evening sky also, note that from somewhere in U.K. Mir will
pass in front of the Moon each night! Please alert local clubs to the
telephone newsline, and general public as Mir can cause quite a stir!

-Tony Ryan, "Astronomy & Space", new International magazine, available from:
              Astronomy Ireland, P.O.Box 2888, Dublin 1, Ireland.
6 issues (one year sub.): UK 10.00 pounds, US$20 surface (add US$8 airmail).
ACCESS/VISA/MASTERCARD accepted (give number, expiration date, name&address).

  (WORLD'S LARGEST ASTRO. SOC. per capita - unless you know better? 0.033%)
Tel: [phone] (UK/N.Ireland) 1550-111-442 (Eire). Cost up to 48p per min

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

Date: Thu, 29 Apr 1993 01:54:32 GMT
From: [e-mail]
Subject: U.K.: See Mir in Evening skies - tell friends!
Newsgroups: sci.astro,sci.space

Astronomy & Space magazine's UK telephone newsline carries the times to
see the Russian Space Station Mir which will be visible every EVENING (some
time between 9 o'clock and midnight) from April 27 to May 7. It's about as
bright as Jupiter at its best. There are two cosmonuats on board.

For the time to watch, tel. [phone] (48p/min peak 36p/min all other
times, but prediction is at start of the weekly message so it only costs a
few pence).

E-mail reports of sightings would be appreciated: give lat/long and UT (a
few seconds accuracy if possible) when it passes ABOVE or BELOW any bright
star (say brighter than mag. 3), planet or Moon.

With Moon in evening sky also, note that from somewhere in U.K. Mir will
pass in front of the Moon each night! Please alert local clubs to the
telephone newsline, and general public as Mir can cause quite a stir!

-Tony Ryan, "Astronomy & Space", new International magazine, available from:
              Astronomy Ireland, P.O.Box 2888, Dublin 1, Ireland.
6 issues (one year sub.): UK 10.00 pounds, US$20 surface (add US$8 airmail).
ACCESS/VISA/MASTERCARD accepted (give number, expiration date, name&address).

  (WORLD'S LARGEST ASTRO. SOC. per capita - unless you know better? 0.033%)
Tel: [phone] (UK/N.Ireland) 1550-111-442 (Eire). Cost up to 48p per min

P.S.: Mir seen right on time April 28th, passed just above Jupiter. Brighter
than Arcturus but dimmer than Jupiter (not one of its highest passes!).

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

End of Space Digest Volume 16 : Issue 502
------------------------------