SkyEye

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

March 2012

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	Thu	First Quarter Moon
2	Fri
3	Sat	Mars at opposition
4	Sun
5	Mon	Mercury at greatest elongation east
6	Tue
7	Wed
8	Thu	Full Moon
9	Fri
10	Sat	Moon at perigee
11	Sun
12	Mon
13	Tue	Jupiter and Venus dominate the western sky with their closest approach this year
14	Wed	The waning gibbous Moon ruins any chance of usefully observing the Gamma Normids.
15	Thu	Last Quarter Moon
16	Fri
17	Sat
18	Sun
19	Mon
20	Tue	Earth at equinox
21	Wed	Mercury at inferior conjunction
22	Thu	New Moon
23	Fri
24	Sat	Uranus at conjunction
25	Sun
26	Mon	Moon at apogee
27	Tue	Venus at greatest elongation east
28	Wed
29	Thu
30	Fri	First Quarter Moon
31	Sat

Coming up next month...

Venus will pass near the Pleiades star cluster at the beginning of the month and Saturn will reach opposition.

The Lyriads meteor shower is blessed with dark skies on 22 April.

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: Aquarius » Pisces
The solar south pole is most inclined toward the Earth early this month. An equinox occurs on Earth on 20 March. The word equinox means 'equal night' so that on this day, the (centre of the) Sun spends an equal amount of time above and below the horizon everywhere on the planet.
Mercury: Pisces
At greatest elongation east on 5 March, it is barely visible above the western horizon at sunset when viewed from the southern hemisphere but appears much higher for observers in northern latitudes. It soon vanishes from view as it heads towards inferior conjunction on 21 March.
Venus: Pisces » Aries » Taurus
The 'evening star' is well placed for viewing in the northern hemisphere; it is high in the west at sunset and continuing to rise. However, Venus is not so spectacular for southern hemisphere observers as it is lower in the sky and slowly descending. Our neighbouring planet is at greatest elongation east on 27 March.
Mars: Leo
At opposition on the third day of the month, the red planet is at its closest to Earth and at its brightest.
Jupiter: Aries
Bright Jupiter is high in the west at sunset and sets mid-evening.
Saturn: Virgo
The ringed planet rises earlier and earlier in the evening as it approaches opposition next month.
Uranus: Pisces
This gas giant is unobservable this month as it is at conjunction on 24 March.
Neptune: Aquarius
A small telescope is necessary to view the most distant planet in the solar system but observations are difficult because Neptune was at conjunction last month and rises during morning twilight.

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 supernova remnant known as the Crab Nebula. Six light years wide and 6500 light years distant, this expanding nebula is the shattered remains of a star that blew up nearly a thousand years ago. At its heart beats a pulsar, a neutron star which spins at the incredible rate of 30 times per second. The supernova explosion which produced this object was observed in 1054 in China, Japan and Arabia. It was also seen in North America by the Anasazi people who lived in what is now New Mexico and who depicted it in a petroglpyh. This image is a composite assembled from 24 individual exposures taken by the Hubble Space Telescope in October 1999, January 2000 and December 2000, and is courtesy of NASA, ESA, Jeff Hester and Allison Loll (Arizona State University). The colours represent different elements which were expelled during the explosion: neutral oxygen (blue), doubly-ionised oxygen (red) and singly-ionised sulphur (green). These elements will find their way into the next generation of stars and planets (and extra-terrestrial life?).