SkyEye

Welcome to SkyEye, your guide to this month's celestial events.

October 2012

The Calendar

All times and dates are given in Universal Time (UT).
Nightly darkness estimates are calculated for 45° N and 30° S.
Like total solar eclipses, lunar occultation events can be seen only from limited regions on Earth (and sometimes not at all if the occultation takes place during daylight hours). However, the Moon will appear close in the sky to its 'target' for some hours either side of the actual occultation, regardless of where you are.

Date		Event
1	Mon
2	Tue
3	Wed
4	Thu
5	Fri	Moon at apogee
5	Fri	Moon occults Jupiter: visible from southernmost points of Australia from about 20:45 UT.
6	Sat
7	Sun
8	Mon	The Last Quarter Moon should not spoil viewing of the Draconids (theoretical peak activity: possibly from 11:15 UT until 20:00 UT).
9	Tue
10	Wed
11	Thu
12	Fri
13	Sat
14	Sun
15	Mon	New Moon
16	Tue
17	Wed	Moon at perigee
17	Wed	Moon occults Mercury: visible from western Alaska from about 02:00 UT.
18	Thu
19	Fri
20	Sat
21	Sun	The waxing crescent Moon favours the Orionids this year (theoretical peak activity: variable but a submaximum is also possible on 17/18 October).
22	Mon	First Quarter Moon
23	Tue
24	Wed
25	Thu	Saturn at conjunction
26	Fri	Mercury at greatest elongation east
27	Sat
28	Sun
29	Mon	Full Moon
30	Tue
31	Wed

Coming up next month...

November brings two eclipses, a total solar eclipse on the 13th and a dim penumbral lunar eclipse 15 days later.

The fascinatingly variable Leonids meteor shower will not be washed out by moonlight this year.

The Solar System

The word planet is derived from the Greek word for 'wanderer'. Unlike the background stars, planets seem to move around the sky, keeping mostly to a narrow track called the ecliptic, the path of the Sun across the stars. Dwarf planets and small solar-system bodies including comets, are not so constrained, often moving far above or below the ecliptic.

Sun: Virgo » Libra
Mercury: Virgo » Libra » Scorpius
An evening sky object, the closest planet to the Sun never appears far from the western horizon as seen from northern latitudes but it rises high into the sky for southern observers and reaches greatest elongation east on 26 October, after which it begins its descent back towards the Sun. A barely visible lunar occultation of Mercury takes place on 17 October.
Venus: Leo » Virgo
The 'morning star' is quite high in the east from the vantage point of the northern hemisphere but is getting lower every day. This nearby planet does not appear nearly so high for southern hemisphere observers and looks to be sinking slightly as the month goes on.
Mars: Libra » Scorpius » Ophiuchus
Look for the red planet in the west after sunset. It sets soon afterwards.
Jupiter: Taurus
This huge gas giant is occulted by the Moon on 5 October. Jupiter rises mid-evening and is easily the brightest 'star-like' object in the sky until the appearance of the 'morning star'.
Saturn: Virgo
This most majestic of planets is lost to view this month as it undergoes conjunction on 25 October.
Uranus: Pisces
At opposition last month, this green-coloured gas giant is up for most of the night, setting before dawn.
Neptune: Aquarius
A small telescope is necessary to view the most distant planet in the solar system which sets just after midnight.

The Celestial Sphere

Constellations are patterns of stars in the sky. The International Astronomical Union (IAU) recognises 88 different constellations. The brightest stars as seen from the Earth are easy to spot but do you know their proper names? With a set of binoculars you can look for fainter objects such as nebulae and galaxies or some of the closest stars to the Sun.

Descriptions of the sky for observers in both the northern and southern hemispheres are available for the following times this month. Subtract one hour from your local time if summer (daylight savings) time is in effect.

Local Time	Northern Hemisphere	Southern Hemisphere
1730 hours (1830 hours summer time)	45° N	30° S
1930 hours (2030 hours summer time)	45° N	30° S
2130 hours (2230 hours summer time)	45° N	30° S
2330 hours (0030 hours summer time)	45° N	30° S
0130 hours (0230 hours summer time)	45° N	30° S
0330 hours (0430 hours summer time)	45° N	30° S
0530 hours (0630 hours summer time)	45° N	30° S

For More Information...

Consult our online glossary for non-technical explanations of many of the astronomical terms used in these pages.
Blue moons, eclipses, the dates of Easter and much more can be found at the Interactive Astronomy Pages.
For more information about the objects and events described in SkyEye, visit these astronomy-related sites.

Credits

Much of this information can be found in this month's issue of your favourite amateur astronomy magazine available in your local bookshop. Another excellent source is the current edition of the Astronomical Calendar by Guy Ottewell and published by the Universal Workshop.

The SkyEye banner features the supernova remnant known as the Crab Nebula. Six light years wide and 6500 light years distant, this expanding nebula is the shattered remains of a star that blew up nearly a thousand years ago. At its heart beats a pulsar, a neutron star which spins at the incredible rate of 30 times per second. The supernova explosion which produced this object was observed in 1054 in China, Japan and Arabia. It was also seen in North America by the Anasazi people who lived in what is now New Mexico and who depicted it in a petroglpyh. This image is a composite assembled from 24 individual exposures taken by the Hubble Space Telescope in October 1999, January 2000 and December 2000, and is courtesy of NASA, ESA, Jeff Hester and Allison Loll (Arizona State University). The colours represent different elements which were expelled during the explosion: neutral oxygen (blue), doubly-ionised oxygen (red) and singly-ionised sulphur (green). These elements will find their way into the next generation of stars and planets (and extra-terrestrial life?).