SkyEye

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

June 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	Fri
2	Sat
3	Sun	Moon at perigee
4	Mon	The Full Moon is partially eclipsed by the shadow of the Earth.
5	Tue	Venus begins a rare transit across the face of the Sun; this occurence was last observed in 2004 and won't be seen again until next century.
6	Wed	Venus at inferior conjunction
7	Thu
8	Fri	Mars at east quadrature
9	Sat
10	Sun
11	Mon	Last Quarter Moon
12	Tue
13	Wed
14	Thu
15	Fri
16	Sat	Moon at apogee
17	Sun	Moon occults Jupiter: visible from northern Canada and Alaska from about 08:30 UT.
18	Mon
19	Tue	New Moon
20	Wed	Earth at solstice
21	Thu
22	Fri
23	Sat
24	Sun
25	Mon
26	Tue
27	Wed	First Quarter Moon
28	Thu
29	Fri	Pluto at opposition
29	Fri	Uranus at west quadrature
30	Sat

Coming up next month...

The occultation of Jupiter by the Moon mid-month and the Delta Aquariids meteor shower near the end of July enliven an otherwise quiet month.

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: Taurus » Gemini
A solstice occurs on Earth on 20 June. The word solstice means 'sun stands still' so that on this day, the solar declination reaches an extreme. In this case, the Sun appears directly over the Tropic of Cancer in the northern hemisphere. From now until the solstice in December, days will be getting shorter in the northern hemisphere and longer in the southern hemisphere. Earlier in the month, the Sun participates in two eclipses, a partial solar eclipse on 4 June and a transit of Venus the following day.
Mercury: Taurus » Gemini » Cancer
This tiny planet reappears in the evening sky this month, rising ever higher above the western horizon throughout the month.
Venus: Taurus
The inferior conjunction of Venus is very special this month; instead of passing above or below the disc of the Sun, the planet moves directly across the face of our star. This transit is a very rare event and is only the eighth one to occur since the invention of the telescope! It can be observed with binoculars or a small telescope but the same precautions must be taken as when viewing a solar eclipse so take care.
Mars: Leo » Virgo
The red planet is at east quadrature on 8 June and sets around midnight.
Jupiter: Taurus
A morning sky object, Jupiter is slowly climbing away from the Sun. It is occulted by the Moon on 17 June.
Saturn: Virgo
Saturn is well-placed for viewing, high above the horizon as the Sun sets and staying aloft until well after midnight.
Uranus: Cetus
Rising just after midnight, this gas giant reaches west quadrature on 29 June.
Neptune: Aquarius
A small telescope is necessary to view the most distant planet in the solar system. At west quadrature last month, look for Neptune rising in the east shortly before midnight.
Pluto: Sagittarius
Now classified as a 'dwarf planet', tiny Pluto reaches opposition on 29 June and is up all night. At its brightest it's only fourteenth magnitude so a moderate-sized telescope (about 30 centimetres or 12 inches) and an excellent finder chart is necessary to locate this distant object.

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?).