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From: TerryMoselat signaol.com
Date: 5 June 2007 20:52:5 Jun 2007
Subject: 4 ISS passes 2nite, Greencastle Trip, IAS Art exhib, NLCs.

Hi all,


You have a very rare chance to see FOUR passes of the ISS tonight!
Thanks to the shallow angle with which the Sun dips below the N horizon
at this time of year, the ISS will be illuminated during 4 successive
passes tonight - something I've never seen before! The following details
are for Belfast, but should apply to most of the NE corner of the island
(you can get details for your own location at www.heavens-above.com

5 June: starts 22h 55m 34s in the SSW, greatest alt = 18 deg at 22h 57m
37s in the SSE

6 June: starts 00h 29m 24s in the WSW, greatest alt = 41 deg at 00h 32m
12s in the SSE

6 June: starts 02h 04m 07s in the W, greatest alt = 38 deg at 02h 06m
51s in the S

6 June: starts 03h 39m 26s in the WSW, greatest alt = 16 deg at 03h 41m
19s in the SSW

You can also see 3 successive passes on the nights of 6/7 June and 7/8


Don't forget the social, astronomical, pyrotechnic, ballistic and
culinary event of the year: the IAA + friends trip to Greencastle
Planetarium for a starshow, rocket-launching, and BBQ.    Our midsummer
event this year is an extra special treat! Those of you who have met or
heard Ash McFadden, the Greencastle Planetarium Director and chief
rocket launcher, will know that a visit there during the summer for a
show and watching or taking part in the rocket launching is a real
treat. (BTW, these are REAL rockets, not compressed air or water. The
big one can go up to over 20,000 feet, although most launches are 'only'
to about 2-3,000 feet.) The fun part is the egg-lofting competition,
whereby you make your own rocket, from a kit which you buy from the
Planetarium, and design it so that it will launch, and land with a
parachute, a standard raw egg (supplied). The rocket that goes highest,
and lands the egg intact afterwards, wins. If by any chance the weather
is too bad for rocket launching, which is VERY unlikely, Ash has
promised us a free laser light show (in which he specialises) in the
planetarium.     Well, we're doing even better than that: we'll have a
special show in the Planetarium, plus it will be exclusively open for us
that day, and after the rocket launching that afternoon, Ash has invited
us all to have our midsummer BBQ either at the Planetarium or at his
house afterwards! Ash lives in a lovely location overlooking Kinnagoe
Bay in Inishowen, a few miles from Greencastle, and has great outdoor
BBQ facilities.    The Planetarium show will be at 13.00; that will be
followed by the rocket launching etc. To allow time to look around the
Planetarium and the Maritime Museum, of which it is part, we will aim to
meet there no later than noon. More details on that later.     Our
normal BBQ rules apply - no charge, you just bring ALL your own stuff
for eating, drinking etc: we + Ash will supply the heat for the cooking.
    There is of course a charge for the Planetarium show, and places are
limited by the size of the Planetarium, so you MUST book a place by
sending a cheque for  7.00 payable to the IAA to our Treasurer, John
Hall, 3 Vaddegan Avenue, Newtownabbey, Co Antrim, BT36 7SP, ASAP!

TRANSPORT: There was not a big demand for the minibus, and in any case
there were complications with getting insurance for the school's minibus
in ROI, so we have decided not to bother with that. Instead we will try
to facilitate car sharing.     PLEASE LET ME KNOW BY RETURN AS FOLLOWS:
1. If you are going and need a lift: state your location, and number of
seats required. 2. If you are going and can offer a lift: state your
location, and number of seats offered. 3. IN BOTH CASES, state whether
you are staying over on the Sunday night, or whether you wish to return
home, and if so what is roughly your preferred return departure time
(allow roughly 1.5 - 2 hours to get back to Belfast.    You may of
course make your own way there if you wish.

NB, It's not a big planetarium, and places are limited, so book now -
first come, first served!

3. Space in Art Exhibition 2007

FROM DEIRDRE KELLEGHER: Announcing 50 years of Space Celebration early
October 2007.  As part of the IAS celebration of its 70 years
involvement in Irish Astronomy, I am organising a Space Art
Competition/Exhibition to be held in Gonzaga College Dublin. If you are
a teacher, or are involved with a youth group here are the details.    I
would like drawings, paintings, sketches, of spacecraft/planets/moons/
whatever you can do best, or models of spacecraft for the exhibition,
all works to be with me by September 30th or earlier if possible.    You
can spark the interest before school finishes for the summer and really
go for it when school returns in September. Planets, Sputnik, Apollo,
Mars Rovers, Cassini indeed any and all spacecraft  or heavenly bodies
are welcome in any art medium. All ages, all abilities    Send to our PO
Box 2547 Dublin 14 or contact me at ias1937@hotmail.com for further
information. I would like young people to explore the exploration of
space through art and celebrate these wonderful robot explorers and the
fabulous work they have done and are doing in space . Human space
exploration celebration art would also be wonderful, ideally you would
bring your work to Gonzaga and collect it afterwards if you wish it
returned    We will have several talks on Space and Space exploration at
this event, details to follow later as it all gels together .    Send me
an e mail if you intend to take part or if you have any contribution to
make in organising or helping us out with this: skysketcher@gmail.com

4. Noctilucent Clouds. The short summer nights bring few benefits for
the amateur astronomer, apart from the warmer temperatures of course.  
 But one is that this is the best time of year to see Noctilucent
Clouds, or NLCs for short. 'Noctilucent' means 'night-shining', and
these beautiful high-altitude clouds do indeed 'shine at night', often
being at their best around local midnight, which in Ireland, allowing
for Summer Time, is usually around 01.20 - 01.40 on your watch. But they
can be seen any time from about 00.30 to 02.30, if the sky is dark
enough, although very near local midnight the Sun may be just too far
below the horizon to illuminate them all fully, especially for those
living further South.      They are thought to be caused by ice crystals
condensing on meteoric dust, i.e. the very fine dust left behind as
meteors burn up on entry high up in the atmosphere, or possibly even
just extremely fine particles 'wafting in' from space.     The reason
that they can be seen is that they are so high up (about 80-85 km) that
the Sun still illuminates them even when it is too far below the local
horizon to illuminate ordinary tropospheric clouds. And this is the best
time of year to see them because the Sun never dips very far below the N
horizon, even at local midnight, giving the best conditions for seeing
them. They can only be seen when the Sun is between 6 and 16 degrees
below the horizon.   They appear low down near the N horizon, often in
the vicinity of Capella, and appear as wispy silvery or sometimes bluish
streaks, often parallel to the horizon. Some 'curls' and 'billows' are
also occasionally visible. They can be seen anywhere in Ireland or
Britain if you have a fairly clear N horizon, but because they occur
mainly at latitudes of 60 degrees to 80 degrees, those in the far South
don't see them as well or as often.    This year may have greater NLC
activity than usual, because they are seen more often around sunspot
minimum, so do have a look on clear evenings. They are quite easy to
photograph, with exposures of 1" - 4" on 400 ISO film (or 2" to 8" on
ISO 200 film, etc); or just experiment with your digital camera and see
what you get with each trial. Successive photos over a period of half an
hour or so may show changes in structure and motion.    Do not be fooled
by ordinary wispy cirrus-type clouds visible late on a summer evening:
the sky needs to be dark enough for you to see the first few
brightest stars in order for NLCs to be properly visible.

  Clear Skies,

Terry Moseley



Last Revised: 2007 June 6th
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