SkyEye

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

May 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	Thu
2	Fri
3	Sat
4	Sun
5	Mon	New Moon
5	Mon	The dark skies which accompany New Moon favour this year's Eta Aquariid meteor shower.
6	Tue	Moon at perigee: expect high tides.
7	Wed
8	Thu
9	Fri
10	Sat	Moon occults Mars: visible from Europe, the Middle East, southern Asia (including India) and western Indonesia from about 10:00 UT.
11	Sun
12	Mon	First Quarter Moon
13	Tue
14	Wed	Mercury at greatest elongation east
14	Wed	Neptune at west quadrature
15	Thu
16	Fri
17	Sat
18	Sun
19	Mon
20	Tue	Full Moon
		Moon at apogee
		Moon occults first-magnitude star Antares: visible from eastern Brazil, southern Atlantic, South Africa and southern Madagascar from about 21:00 UT.
21	Wed
22	Thu	Saturn at east quadrature
23	Fri
24	Sat
25	Sun
26	Mon
27	Tue	Moon occults Neptune: visible from the western half of Africa from about 1:00 UT.
28	Wed	Last Quarter Moon
29	Thu
30	Fri
31	Sat

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: Aries -> Taurus
Mercury: Taurus
Observers in the northern hemisphere finally get their chance to view this elusive planet as it vaults high into the northwestern sky at sunset. It begins its descent back towards the horizon after reaching greatest elongation east on 14 May and disappears into the twilight by the end of the month.
Venus: Aries -> Taurus
Too low to see from the northern hemisphere and descending fast as seen from the southern hemisphere, the "morning star" vanishes from view by mid-month but will reappear next month in the west after sunset.
Mars: Gemini -> Cancer
The red planet passes through M44, the Beehive Cluster on 22-24 May but look for it soon after dark as it sets around midnight.
Jupiter: Sagittarius
The largest planet in the solar system finally begins to rise before midnight.
Saturn: Leo
Quadrature is the best time to observe the planet through a telescope because the shadow cast by the planetary disc onto the rings is most pronounced. The rings stop widening this month so don't delay in viewing this interesting event. Saturn makes its closest approach to the first-magnitude star Regulus early in the month and both objects set just after midnight.
Uranus: Aquarius
This distant gas giant rises about an hour after its neighbour Neptune.
Neptune: Capricornus
A small telescope is necessary to view the most distant planet in the solar system. Because it is at west quadrature on 14 May, it is almost exactly opposite from Saturn in the sky. (Saturn is at east quadrature just over a week later.) Thus, Neptune rises as Saturn sets.

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.