SkyEye

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

June 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	Sat
2	Sun
3	Mon
4	Tue
5	Wed
6	Thu
7	Fri
8	Sat	New Moon
9	Sun	Moon at apogee
10	Mon
11	Tue
12	Wed	Mercury at greatest elongation east
13	Thu
14	Fri
15	Sat
16	Sun	First Quarter Moon
17	Mon
18	Tue	The Moon occults first-magnitude star Spica: visible from the southern half of Africa and Madacascar from about 18:00 UT.
19	Wed	Jupiter at solar conjunction
20	Thu
21	Fri	Earth at solstice
22	Sat
23	Sun	Since the closest perigee of the year is happening only four hours prior to the Full Moon, very high tides can be expected.
24	Mon
25	Tue
26	Wed
27	Thu
28	Fri
29	Sat
30	Sun	Last Quarter Moon

Coming up next month...

The Earth reaches the point in its orbit where it's furthest from the Sun.

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: Gemini
The smallest planet in the solar system reaches greatest elongation east on 12 June. An evening sky object, it puts on a slightly better show seen from northern latitudes rather than southern. For the best views of this elusive object, look for Mercury in the west after sunset around mid-month.
Venus: Taurus » Gemini » Cancer
The evening star is still soaring upward for viewers in the southern hemisphere but its distance above the horizon for those in the north levels off late this month.
Mars: Taurus
Mars is slowly pulling away from the Sun in the morning sky but remains difficult to see this month.
Jupiter: Taurus » Gemini
The largest planet in the solar system vanishes from the night sky, undergoing conjunction with the Sun on 19 July. This time, Jupiter will actually be occulted by the Sun instead of passing either north or south of our star's disc.
Saturn: Virgo
Saturn is well-placed for viewing this month, not setting until after midnight.
Uranus: Pisces
This ice giant is a morning sky object, rising about 90 minutes after Neptune.
Neptune: Aquarius
A small telescope is necessary to view the most distant planet in the solar system. It rises at or just before 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 young star cluster located less than 100 light years from the centre of our galaxy, the Quintuplet Cluster. The massive stars in this cluster are around 4 million years old and some are on the verge of exploding as supernovae. The cluster has not long to live in any case; the extreme gravitational tidal forces in the galactic core will rip it apart in a few million years. This 1997 Hubble Space Telescope image is courtesy D. Figer (STScI) and NASA.