SkyEye

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

May 2013

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	Wed
2	Thu	Last Quarter Moon
3	Fri
4	Sat
5	Sun
6	Mon	The waning crescent Moon should not unduly interfere with observations of the Eta Aquariids (theoretical peak activity: about 01:00 UT).
7	Tue
8	Wed
9	Thu
10	Fri	The New Moon passes in front of the Sun's disc to create an annular eclipse.
11	Sat	Mercury at superior conjunction
12	Sun
13	Mon	Moon at apogee
14	Tue
15	Wed
16	Thu
17	Fri
18	Sat	First Quarter Moon
19	Sun
20	Mon
21	Tue
22	Wed	The Moon occults first-magnitude star Spica: visible from Indonesia, northeastern Australian coast and south Pacific from about 08:45 UT.
23	Thu
24	Fri
25	Sat	The Full Moon undergoes a barely detectable penumbral eclipse.
26	Sun	Moon at perigee
26	Sun	Neptune at west quadrature
27	Mon
28	Tue
29	Wed
30	Thu
31	Fri	Last Quarter Moon: the second Full Moon in a month has a special name but what about the other phases?

Coming up next month...

Solstice ushers in summer north of the equator and winter in the southern hemisphere.

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
An annular solar eclipse is on view on 9-10 May.
Mercury: Pisces » Aries » Taurus » Gemini
A morning sky object at the beginning of the month, Mercury is soon lost to view as it reaches superior conjunction on 11 May. This conjunction is somewhat rare in that the planet actually passes behind the disc of the Sun as seen from the Earth. Mercury reappears in the evening sky late in the month, there to remain until mid-July.
Venus: Aries » Taurus
The evening star is climbing higher in the western sky at sunset but is still very low and difficult to spot. At the moment, it is best seen from the northern hemisphere but Venus will appear quite high in the sky for southern hemisphere viewers later in the year.
Mars: Aries » Taurus
At solar conjunction last month, the red planet is a morning sky object but is very difficult to spot low in the east before sunrise.
Jupiter: Taurus
On its way to solar conjunction next month, the gas giant is setting ever closer to the Sun. Still visible in the evening twilight early in the month, it will be lost to view by the end.
Saturn: Libra » Virgo
At opposition near the end of last month, the ringed wonder is aloft virtually all night.
Uranus: Pisces
The green ice giant is a morning sky object, rising about 90 minutes after its neighbour Neptune.
Neptune: Aquarius
A small telescope is necessary to view the most distant planet in the solar system as it reaches west quadrature on 26 May. Look for it rising in the east 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 a false-colour view of the Sun, taken by the Transition Region and Coronal Explorer spacecraft. The image shows a moderately active solar corona on 2 August 1999. The blue shows gas at 1 million degrees, the green at 1.5 million degrees and the red at 2 million degrees. This image is courtesy of the Stanford-Lockheed Institute for Space Research. TRACE is part of the NASA Small Explorer programme.