SkyEye

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

May 2009

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	Fri	First Quarter Moon
2	Sat
3	Sun
4	Mon
5	Tue
6	Wed	The waxing gibbous Moon should set in time to allow some observations of the Eta Aquariids in the early hours of the morning.
7	Thu
8	Fri
9	Sat	Full Moon
10	Sun	Moon occults Antares: visible from about 1900 UT in the southeastern Europe, northeastern Africa, the Middle East and southern Asia.
11	Mon
12	Tue
13	Wed
14	Thu	Moon at apogee
15	Fri
16	Sat	Jupiter at west quadrature
17	Sun	Neptune at west quadrature
17	Sun	Last Quarter Moon
18	Mon	Mercury at inferior conjunction
19	Tue
20	Wed
21	Thu
22	Fri
23	Sat
24	Sun	New Moon occults the Pleiades: too close to the Sun to observe.
25	Mon
26	Tue	Moon at perigee
27	Wed
28	Thu
29	Fri
30	Sat
31	Sun	First Quarter Moon

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
The "evening star" is best seen from the northern hemisphere early this month but is too close to the Sun to see by mid-month. Southern hemisphere viewers lose it even earlier in the month. The innermost planet of the solar system undergoes inferior conjunction on 18 May and reappears in the morning sky just before sunrise to early risers in the southern hemisphere. However, observers in northern latitudes will have to wait until the end of the month or even early June to catch a glimpse of this elusive planet in the dawn sky.
Venus: Pisces
The "morning star" climbs high above the eastern horizon for southern hemisphere observers and becomes easier to see for those in the north as well.
Mars: Pisces -> Cetus -> Pisces
The red planet is rising farther ahead of the Sun and is starting to escape the morning twilight.
Jupiter: Capricornus
West quadrature occurs on 16 May, making this an excellent time to observe the interplay of shadows between the planet and its brightest satellites. Get up early (or stay up late) to see it: Jupiter (along with Neptune) rises after midnight.
Saturn: Leo
The rings are at their most open before the ring-plane crossing event in September. It is well-placed for observing during the evening this month.
Uranus: Pisces
This distant gas giant rises about an hour after its fellow gas giants Jupiter and Neptune.
Neptune: Capricornus
A small telescope is necessary to view the most distant planet in the solar system. It is at west quadrature on 17 May, the day after Jupiter reaches the same configuration.

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 SkyEye banner features a view of Saturn from its satellite Iapetus and is courtesy of NASA/JPL/Space Science Institute. Of all the major satellites of Saturn, Iapetus is the only one with a significant orbital inclination. Thus, whilst the rings appear nearly edge-on from all of the other major satellites, from Iapetus they are usually seen at a tilt. This image was taken during the Cassini-Huygens mission on 10 September 2007 and consists of 15 red, green and blue spectral filter images.