1. MOON TO PASS IN FRONT OF
VENUS!
As announced in our June magazine, for the first
time in 3 years the Moon will pass in front of ("occult") the planet Venus on
Monday June 18 as seen from Ireland. Back on May 21st, 2004 it was cloudy from
Dublin at Astronomy Ireland's office and Shop so it's been a long time since
such an amazing sight has been seen.
It will be daytime when the event happens
but with binoculars and telescopes everyone should be able to see
it.
First a warning, DO NOT LOOK AT THE SUN WITH YOUR
EYES, BINOCULARS OR TELESCOPES! YOU WILL BE BLINDED. Try to stand in the shadow
of a building so the Sun is just covered by the building.
The exact time that the Moon passes in front of
Venus will vary by up to 6 minutes depending on where you are located around
Ireland. The Moon will pass in front of Venus from between 2:47pm and 2:53pm
with those on the West coast seeing it earlier, and those in the East see it
those few minutes later.
Starting around 2pm to 2:30pm, with the naked eye,
look 45 degrees to the left of the Sun and about 10 degrees lower than the Sun
and you should be able to see the thin crescent Moon (14% of its diameter will
be sunlit). Now aim your binoculars at the Moon (being very careful never to
look near the Sun!) and you should easily see Venus just to the lower left of
the Moon in broad daylight with even the smallest binoculars. 10x50s are
ideal. If it's a good clear day you should be able to see Venus with the naked
eye next to the Moon! This will be a remarkable sight with the naked eye or
binoculars and we want you to email us to tell us if you could see this or
not:
Now for the occultation itself: If you have even a
small telescope you'll get an amazing view of the occultation at the times above
(2:47pm-2:53pm)! The disk of Venus is about 26 arc seconds wide and 44% sunlit
so it will appear almost 'half full'. The dark (invisible) edge of the Moon will
begin to cover Venus' brilliant disk and it may take a few seconds for you to
realise the occultation has begun. It will take 72 seconds for the Moon's edge
to cross Venus' full diameter, but because only 44% of Venus is sunlit you'll
only see the sunlit side of Venus passing behind the Moon for roughly half that
time i.e. about 36 seconds. Try to time this if you can. It should be one of the
most remarkable 36 seconds of your life. This "disappearance" happens slightly
left of the bottom edge of the Moon's (dark and therefore invisible) edge. See
link to diagram below.
Then you have to wait an hour and a quarter until
Venus reappears from behind the Moon. Again, the times vary depending on where
you are around Ireland but it will be between 4:03pm and 4:12pm, again, with
those in the West seeing it first.
As Venus will "reappear" from behind the bright
(sunlit) edge of the Moon a telescope will be better than binoculars to get the
first glimpse of this occurring. Again try to time how long it takes and email
us your report. Venus will reappear from behind the right hand edge of Moon so
have your telescope or binoculars trained there. For naked eye observers we want
to know how soon after Venus begins to reappear from behind the Moon can you see
it? Send us your location and the exact time (dial 1191 to get the speaking
clock which is very accurate).
WEATHER: Both the disappearance and the
reappearance happen high in Irish skies so let's hope for clear weather or at
least some breaks in any clouds. Don't give up just because it's looking dismal.
We saw the Saturn occultation on May 22nd when the clouds miraculously parted
just minutes before the event!
And remember, for several hours after the event you
will still get a chance to locate Venus in the daytime sky with the naked eye by
using the Moon as signpost, an observation well worth performing. After dark,
the Moon will be spectacularly close to Venus all evening also. Don't miss
this!
See the diagram at www.astronomy.ie/press/Venus_Occ.jpg.
There are more details of all this in the Sky
Diary pages of the June issue of our magazine on page 27 and diagrams too (but
note the times on the diagram "15:10" and "16:00" should read "16:10" and
"17:00").
Click on www.astronomy.ie/sub if you don't
already get our magazine, there are lots of other things to see, all for only
5euro incl postage.
We await your reports (and photos?) so please email
observe@astronomy.ie and we'll report
your sighting for posterity in our magazine.
2. Lots More To See
I.S.S.+Shuttle: record numbers
called our Newslines to get the time to see these last week and hear the latest
news. They are no longer visible from Ireland but you can still follow the story
until Atlantis lands around 7pm June 21 at www.nasa.gov/shuttle. I.S.S. is next
visible in Irish skies August 4th-16th. Hundreds more beginners joined this
emailing list as a result - welcome! If you want to get our magazine or if you
know anyone else interested in space please get them to sign up at www.astronomy.ie/sub
Venus: blazing in the West until
after midnight until mid July. View it with a telescope in strong twilight when
it's highest and glare against a dark sky is less of a problem. Telescope owners
will now see its disk swell up to over 40 arc second wide crescent by mid July -
a rare sight.
Saturn: easy to find every evening
as Venus is a getting close (closest on June 30 just 0.7 degree apart!).
Glorious sight in a telescope with its rings and its main moons on view (see
Titan diagram in our magazine's Sky Diary). Only a few more weeks to see it well
so get your telescope out.
Jupiter: the 'star' of the summer.
Now closest to Earth and visible all night in the South sky as the brightest
'star' (after Venus). Brilliant sight in a telescope with some or all of its 4
main moons visible every night even in binoculars. Times to see its Great Read
Spot amongst its impressive cloud belts are in our magazine's Sky Diary pages.
Moon: This is always a fantastic
sight in a telescope and over the next 2 weeks it will be a specially glorious
sight in evening skies giving lots to see. Try 'snapping' it at your telescope's
eyepiece with even your camera phone and email us any good results.
Sun: Remember, new sunspots can
break out any time. As they did last month. NEVER LOOK DIRECTLY AT THE SUN - use
AstroSolar Filter sheets available from our Shop. Call the number
below.
Great Summer Planet Viewing: Don't
let the late evenings put you off observing when there is so much planetary
viewing to do, you can even observe Venus in daylight remember! So get your
telescopes out and keep sending in those reports and photos to observe@astronomy.ie this summer.
Telescopes: If you don't have a
telescope yet you can get advice 6 days a week from our Shop staff on (01) 847
0777 and remember they are there for the rest of your life to help you use the
telescope to its best so please do call for advice - you can get an impressive
telescope for just a few euros per week e.g. the new NexStar SE range which were featured on the insert in the
latest magazine (www.astronomy.ie/NexStarSE.doc)
and which are a real price breakthrough, and our Shop will match or beat
any price in the world.
Astronomy
Ireland
Society ·
Magazine ·
Telescopes
