SkyEye

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

October 2011

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	Sat
2	Sun
3	Mon
4	Tue	First Quarter Moon
5	Wed
6	Thu
7	Fri
8	Sat	The waxing gibbous Moon rather spoils viewing of the Draconids (theoretical peak activity: possibly from 16:00 UT until 21:00 UT).
9	Sun
10	Mon
11	Tue
12	Wed	Full Moon
12	Wed	Moon at apogee
13	Thu	Saturn at conjunction
14	Fri
15	Sat
16	Sun
17	Mon
18	Tue
19	Wed
20	Thu	Last Quarter Moon
21	Fri	The waning crescent Moon seriously interferes with the Orionids this year.
22	Sat
23	Sun
24	Mon
25	Tue
26	Wed	Moon at perigee: with only 7 hours separating perigee and New Moon, expect unusually high tides.
26	Wed	New Moon
27	Thu
28	Fri
29	Sat	Jupiter at opposition
30	Sun
31	Mon

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
This tiny planet is mostly lost to view until the latter part of the month when it appears in the west after sunset. It remains low and difficult to see from the northern hemisphere but gains considerable altitude as viewed from southern latitudes.
Venus: Virgo » Libra
Southern hemisphere observers get the best views of the "evening star" this month although it is still quite low in the western sky after sunset.
Mars: Cancer » Leo
Observers will have to stay up well past midnight to see Mars pass near M44 (the Beehive Cluster) at the beginning of the month.
Jupiter: Aries
The largest planet blazes at a brilliant -3 magnitude as it reaches opposition on 29 October. It can be seen virtually all night.
Saturn: Virgo
This most majestic of planets is lost to view this month as it undergoes conjunction on 13 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 beautiful planetary nebula NGC 2818. A planetary nebula is a glowing shell of gas surrounding a dying star. When a star begins to run out of fuel and expands into a red giant, the outer layers of the star are expelled into space, enriching the surrounding area with the heavy elements manufactured by the parent star. The remaining hot stellar core ionises the ejecta, causing it to glow for a few tens of thousands of years. Eventually the star fades away and nebula is no longer visible. This image was taken by the Hubble Space Telescope in November 2008 and is courtesy NASA, ESA, and the Hubble Heritage Team (STScI/AURA). The red colour represents nitrogen, green represents hydrogen and blue represents oxygen.