Space - Tullamore Astronomical Society
Space - Tullamore Astronomical Society
Space - Tullamore Astronomical Society
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UPCOMING ASTRONOMICAL EVENTS<br />
Compiled by John Flannery, South Dublin AS<br />
Summary<br />
Winter Solstice occurs on December 21 st at 18:35hrs:<br />
Winter officially begins in the Northern Hemisphere.<br />
Eclipses<br />
No eclipses occur during this time.<br />
The Planets<br />
Heads<br />
Binocular users may just about spot Mercury in the<br />
evening sky around time of greatest eastern elongation on<br />
November 3 rd (24°) given a clear south-western horizon.<br />
Your best chance of seeing the planet falls during<br />
December in the morning sky. Mercury begins December<br />
about 5° above the south-eastern skyline at the beginning of<br />
civil twilight and climbs higher each day until greatest<br />
western elongation (21°) on the 12 th when it can be found at<br />
an altitude of 9.5° around the same time of morning.<br />
Thereafter, it slowly retreats sunward (but remains quite<br />
bright at magnitude -0.4) and will probably be lost to view<br />
by New Year’s Day. A word of caution; if you are looking<br />
for Mercury in any sort of optical instrument make sure you<br />
do not accidentally sweep up the Sun in the field. It<br />
therefore makes sense to look for the planet in binoculars or<br />
a telescope after sunset or before sunrise. Advanced<br />
amateurs do observe the planet in daylight close to the Sun<br />
but only by taking careful precautions and having<br />
telescopes with setting circles that allow you to accurately<br />
“home in” on Mercury’s position in the sky.<br />
Venus has remained quite low in the evening sky all year<br />
but is now beginning to pull clear, gaining in altitude<br />
during the two-month period covered by these notes. It lies<br />
highest in our evening skies in mid-December (still only<br />
about 12 in altitude though) and reaches greatest brilliancy<br />
on December 9 th (magnitude -4.6).<br />
Telescopes will show the phase of the planet<br />
change from half to a thin crescent over the next two<br />
months, while the diameter of the disk swells from 24.5" to<br />
55". You should be able to spot Venus as a tiny crescent in<br />
binoculars by the end of the year. The Moon is nearby on<br />
November 5 th and December 4 th , making for an attractive<br />
sight.<br />
Still awaiting launch at time of writing is the<br />
European <strong>Space</strong> Agency’s Venus Express mission,<br />
designed to study the atmosphere and space-environment of<br />
Venus. Following launch, the spacecraft will take 153 days<br />
to reach Venus after which it will settle into orbit and begin<br />
science operations. Although previous missions such as<br />
Magellen have used radar to pierce the veil shrouding this<br />
mysterious world, we are still no closer to understanding<br />
UP<br />
why Earth’s sister planet boasts a greenhouse effect run<br />
riot.<br />
Mars continues to steal the show as it reaches opposition<br />
on November 7 th in the constellation Aries and shines at<br />
magnitude -2.3 throughout the night. The disk measures<br />
20" at this time and the Red Planet is sure to be carefully<br />
scrutinised by backyard observers. Or so we hope! Recent<br />
reports on the International Mars-watch page<br />
(http://elvis.rowan.edu/marswatch/) suggest that a dust<br />
storm first noticed brewing on the planet in mid-October<br />
has now increased in intensity. Should the storm grow in<br />
size it will gradually obscure features for observers and the<br />
disk will look bright orange. Any reports you have should<br />
be forwarded to the Mars-watch web site mentioned above.<br />
A detailed article on observing the planet during this<br />
apparition can be found at<br />
http://www.tnni.net/~dustymars/Article_2005.htm The<br />
Moon is close to Mars on November 14 th and December<br />
11 th .<br />
Jupiter necessitates an early rise as it is strictly a morning<br />
sky object during November and December. You will<br />
probably only first spot the cream-coloured planet from the<br />
second week of November onwards as its time of rising<br />
becomes progressively earlier ahead of the Sun. Jupiter<br />
shines at magnitude -1.7 at the moment and the disk is quite<br />
small (for Jupiter!), measuring 32". The planet moves from<br />
Virgo into Libra at the start of December. Look for the<br />
Moon nearby on the mornings of November 29 th and<br />
December 27 th .<br />
Saturn rises before midnight at the beginning of<br />
November and a little earlier each night until the end of the<br />
period covered by these notes. It brightens slowly from<br />
magnitude 0.3 to magnitude 0.0 during November and<br />
December as it closes in on its January 2006 opposition<br />
date.<br />
The beautiful ring system is easily visible in a<br />
small telescope but if you’ve been keeping a keen eye on<br />
the planet the last few years you will notice that they are<br />
gradually closing up -- their Earthward tilt is now around<br />
17.5°. It’s all to do with the inclination of Saturn’s orbit<br />
and ours; twice during Saturn’s 29 year long circuit of the<br />
Sun the rings appear edge-on to Earth-based observers as<br />
we pass through their plane. The rings will next be edge-on<br />
in September 2009 and will disappear from view in all but<br />
larger amateur telescopes.<br />
The Ringed Planet is still a dramatic sight at the<br />
moment close to the Beehive star cluster in Cancer that was<br />
mentioned in the previous issue’s notes. With the Moon<br />
close to the planet too on the evenings of November 22 nd<br />
and December 18 th it will add to an already dramatic sight<br />
in binoculars.<br />
Details for Uranus, Neptune, and Pluto are beyond<br />
10<br />
Réalta – Volume 7, Issue 2 – November/December 2005 – <strong>Tullamore</strong> <strong>Astronomical</strong> <strong>Society</strong>