SkyEye

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

June 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	Tue
2	Wed
3	Thu	Apogee
4	Fri	Last Quarter Moon
5	Sat
6	Sun
7	Mon
8	Tue	First encounter in the triple conjunction of Jupiter and Uranus
9	Wed
10	Thu	Moon occults the Pleiades: visible from around 19:30 UT in southeastern Australia and New Zealand.
11	Fri
12	Sat	New Moon
13	Sun
14	Mon
15	Tue	Perigee
16	Wed
17	Thu
18	Fri	1 Ceres at opposition
19	Sat	First Quarter Moon
19	Sat	Saturn at east quadrature
20	Sun
21	Mon	Solstice
22	Tue	Uranus at west quadrature
23	Wed	Jupiter at west quadrature
24	Thu
25	Fri	Pluto at opposition
26	Sat	Full Moon
26	Sat	A partial lunar eclipse is visible from the Pacific Ocean, Australasia, India and the Americas.
27	Sun
28	Mon	Mercury at superior conjunction
29	Tue
30	Wed

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 21 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.
Mercury: Aries » Taurus » Gemini
This tiny planet is best seen from southern latitudes this month but it sinks rapidly toward the eastern horizon before sunrise and disappears late in the month, with superior conjunction occurring on 28 June.
Venus: Gemini » Cancer » Leo
Southern hemisphere observers finally get the best views of the "evening star" as it continues to rise higher and higher above the western horizon after sunset. However, to those watching from the north, this bright planet actually gets lower in the sky as the month wears on.
C/2009 R1 (McNaught): Andromeda » Perseus » Auriga
Robert H. McNaught, famous for his discovery of C/2006 P1 McNaught, found this icy visitor in September 2009 from images taken at Siding Spring Observatory in Australia. Already brightening more than expected, this comet is predicted be a naked eye object by mid-month. Northern hemisphere observers should look for it from midnight onwards. It passes close todelta Persei on 14 June and beta Aurigae (Menkalinan) ten days later. Because of its trajectory, it is unlikely that viewers from the southern hemisphere will be able to see this comet as a naked eye object.
Mars: Leo
The red planet sets around midnight.
1 Ceres: Sagittarius
The largest dwarf planet in the main asteroid belt glides past M8, the Lagoon Nebula, the first day of the month. Later, on 18 June, it reaches a maximum brightness of seventh magnitude at opposition.
Jupiter: Pisces
Jupiter and Uranus begin their triple conjunction on 8 June. Jupiter reaches west quadrature on 23 June, making this an excellent time to observe the interplay of the shadow of the planetary disk and the Galilean satellites.
Saturn: Virgo
The ringed planet is at east quadrature on 19 June and sets just before midnight.
Uranus: Pisces
Rising just after midnight, this gas giant has its first encounter of three with Jupiter on 8 June. It reaches west quadrature on 22 June, the day before Jupiter reaches the same phase.
Neptune: Aquarius
A small telescope is necessary to view the most distant planet in the solar system. Look for Neptune rising in the east just before midnight.
Pluto: Sagittarius
Now classified as a "dwarf planet", tiny Pluto reaches opposition on 25 June and is up all night. At its brightest it's only fourteenth magnitude so a moderate-sized telescope (about 12 inches or 30 centimetres) 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 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).