SkyEye

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

June 2009

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	Mon
2	Tue
3	Wed
4	Thu
5	Fri	Saturn at east quadrature
5	Fri	Venus at greatest elongation west
6	Sat
7	Sun	Full Moon occults Antares: visible from about 0130 UT in southeastern North America (including Mexico and Central America), northern South America and the westernmost parts of Africa.
8	Mon
9	Tue
10	Wed	Moon at apogee
11	Thu
12	Fri
13	Sat	Mercury at greatest elongation west
14	Sun
15	Mon	Last Quarter Moon
16	Tue
17	Wed	Uranus at west quadrature
18	Thu
19	Fri
20	Sat	Moon occults the Pleiades: visible from about 1400 UT in Hawaii.
21	Sun	Solstice on Earth
22	Mon	New Moon
23	Tue	Pluto at opposition
23	Tue	Moon at perigee: high tides can be expected since New Moon occurs so near to perigee.
24	Wed
25	Thu
26	Fri
27	Sat
28	Sun
29	Mon	First Quarter Moon
30	Tue

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: Taurus
Southern observers get the best views of Mercury early in the month as it rises high in the dawn sky. Greatest elongation west is on 13 June. This tiny planet begins to sink back towards the eastern horizon as the month wears on.
Venus: Pisces -> Aries -> Taurus
The "morning star" is still best seen from the southern hemisphere, even though it is descending slightly towards the horizon. It continues to climb higher in the dawn sky for observers in the north. Greatest elongation west occurs on 5 June.
Mars: Aries
The red planet now rises well ahead of morning twilight and is found in the company of Venus.
Jupiter: Capricornus
The largest planet in the solar system rises before midnight.
Saturn: Leo
The ringed planet reaches east quadrature on 5 June, putting it in the opposite part of the sky from Uranus. The rings are appearing thinner and thinner in telescopes as ring-plane crossing approaches in September.
Uranus: Pisces
This gas giant, always just on the verge of naked eye visibility, reaches west quadrature on 17 June, rising about midnight.
Neptune: Capricornus
A small telescope is necessary to view the most distant planet in the solar system. Currently found in the sky very near to bright Jupiter, Neptune rises before midnight.
Pluto: Sagittarius
Now classified as a "dwarf planet", tiny Pluto reaches opposition on 23 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 view of Saturn from its satellite Iapetus and is courtesy of NASA/JPL/Space Science Institute. Of all the major satellites of Saturn, Iapetus is the only one with a significant orbital inclination. Thus, whilst the rings appear nearly edge-on from all of the other major satellites, from Iapetus they are usually seen at a tilt. This image was taken during the Cassini-Huygens mission on 10 September 2007 and consists of 15 red, green and blue spectral filter images.