SkyEye

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

October 2008

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	Wed
2	Thu
3	Fri
4	Sat	Moon occults first-magnitude star Antares: visible from southern Africa and most of Australia from about 8:00 UT.
5	Sun	Moon at apogee
6	Mon	Jupiter at east quadrature
6	Mon	Mercury at inferior conjunction
7	Tue	First Quarter Moon
8	Wed	Despite the waxing gibbous Moon, this is a good year to check the unpredictable Draconid meteor shower.
9	Thu
10	Fri	Moon occults Neptune: visible from the Far East from about 9:00 UT.
11	Sat
12	Sun
13	Mon
14	Tue	Full Moon
15	Wed
16	Thu
17	Fri	Moon at perigee
18	Sat
19	Sun
20	Mon
21	Tue	Last Quarter Moon
21	Tue	The Orionid meteor shower is washed out by the Last Quarter Moon.
22	Wed	Mercury at greatest elongation east
23	Thu
24	Fri
25	Sat
26	Sun
27	Mon
28	Tue	New Moon
29	Wed	4 Vesta at opposition
30	Thu
31	Fri	A cross-quarter day occurs midway between equinoxes and solstices.

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
This elusive planet is not visible to northern hemisphere observers until mid-month when it appears in the morning sky. It then climbs quite high, reaching greatest elongation east on 22 October, before descending towards the horizon again. Viewers in the southern hemisphere have a much poorer view. Although Mercury is still visible at sunset for the first few days, it disappears as it reaches conjunction on 6 October and stays quite low in the morning sky when it finally reappears.
Venus: Libra -> Scorpius -> Ophiuchus
The "evening star" is high in the sky for those seeing it from the southern hemisphere but Venus remains quite low in the west when viewed from the north.
Mars: Virgo -> Libra
The red planet is getting too close to the Sun to be observered.
4 Vesta: Cetus
At opposition on 29 October, 4 Vesta is the only small solar system body in the asteroid belt to reach naked-eye visibility.
Jupiter: Sagittarius
Jupiter is at east quadrature on 6 October. Quadrature is always an excellent time to view this planet through a telescope, as the interplay of shadows (planet on satellites and vice versa) is at its most pronounced. The largest planet in the solar system is found in the west at dusk, setting by late evening.
Saturn: Leo
The ringed planet rises early in the morning, sharing "morning star" duties with Mercury.
Uranus: Aquarius
At opposition last month, this green-coloured gas giant sets before dawn.
Neptune: Capricornus
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 at Furman University.

The image of the variable star V838 Monocerotis in the SkyEye banner is courtesy of NASA, ESA and the Hubble Heritage Team (STScI/AURA). Located 20,000 light years away in the constellation of Monoceros, V838 Mon temporarily brightened in early 2002. The reason for this outburst is not understood. The resulting light echo, the light from the stellar explosion illuminating the dust surrounding the the star, was captured by the Hubble Space Telescope in October of that year.