SkyEye

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

May 2010

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	Mars at east quadrature
5	Wed
6	Thu	Last Quarter Moon at apogee
		2 Pallas at opposition
		The light from the Moon proves troublesome for observers hoping to glimpse the Eta Aquariids.
7	Fri
8	Sat
9	Sun
10	Mon
11	Tue
12	Wed
13	Thu
14	Fri	New Moon
15	Sat
16	Sun	Moon occults Venus: visible from about 11:20 UT in southeastern Asia and Indonesia.
17	Mon
18	Tue
19	Wed	Neptune at west quadrature
20	Thu	First Quarter Moon at perigee
21	Fri
22	Sat
23	Sun
24	Mon
25	Tue
26	Wed	Mercury at greatest elongation west
27	Thu	Full Moon
28	Fri
29	Sat
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: Aries » Taurus
Mercury: Aries » Pisces » Cetus » Aries
The southern hemisphere finally gets the best views of this elusive planet when it reappears early this month in the morning sky and rises high in the east. It stays stubbornly close to the horizon when viewed from northern latitudes. Mercury reaches greatest elongation west on 26 May.
Venus: Taurus » Gemini
The "evening star" is high above the western horizon at sunset for northern hemisphere observers and rising higher throughout the month.
Mars: Cancer » Leo
At east quadrature on 4 May, Mars sets just after midnight.
2 Pallas: Hercules » Corona Borealis
This small solar system body shines at a feeble ninth magnitude when it reaches opposition on 6 May.
Jupiter: Aquarius » Pisces
The largest planet in the solar system rises two to three hours before sunrise.
Saturn: Virgo
The ringed planet sets during the early morning hours.
Uranus: Pisces
The most distant planet that can be seen with the naked eye rises just after Jupiter early in the morning.
Neptune: Aquarius
A small telescope is necessary to view the most distant planet in the solar system. It reach west quadrature on 19 May and rises 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 SkyEye banner features a collision of galaxy clusters and is courtesy of NASA, ESA, CXC, M. Bradac (University of California, Santa Barbara) and S. Allen (Stanford University). When MACS J0025.4-1222 was formed, gravity caused the ordinary matter in the colliding galaxy clusters to slow down whereas the dark matter, which at best interacts only weakly with itself, continued on its original course. Thus, this object provides both confirmation of the existence of dark matter and a further understanding of its properties. This image is a composite of Hubble Space Telescope and Chandra X-ray Observatory data where dark matter is coloured blue (mapped by Hubble using gravitational lensing techniques) and ordinary matter is coloured pink (mapped by Chandra detecting X-rays from gas heated by the collision).