Welcome to SkyEye, your guide to this month's celestial events. All times and dates are given in Universal Time (UT). Nightly darkness estimates are calculated for Greenwich, London (51.5° N, 0° W).

Calendar of Events - July 2005

Date Event
1 Fri Jupiter at east quadrature
2 Sat
3 Sun
4 Mon Deep Impact encounters 9P/Tempel 1, one day before the comet's perihelion.
5 Tue Earth at aphelion: aphelion occurs always occurs between 2 July and 6 July
6 Wed New Moon
7 Thu
8 Fri Moon at apogee
9 Sat Mercury at greatest elongation east
10 Sun
11 Mon
12 Tue Mars at west quadrature
13 Wed Moon occults Jupiter
14 Thu First Quarter Moon
15 Fri
16 Sat
17 Sun
18 Mon Moon occults first-magniture star Antares: visible from Mexico, Central America and northern parts of South America beginning at approximately 0300 UT.
19 Tue
20 Wed
21 Thu Full Moon
Moon at perigee: high tides can be expected whenever Full Moon and perigee occur close together.
22 Fri
23 Sat Saturn at conjunction
24 Sun
25 Mon
26 Tue
27 Wed
28 Thu The waning Moon does not assist viewing of the Delta Aquariids meteor shower but southern hemisphere observers should give it a try.
Last Quarter Moon
29 Fri
30 Sat
31 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.

Sun
Location: Gemini -> Cancer
Mercury
Location: Cancer -> Leo -> Cancer
Mercury and Venus begin the month very close together in the west after sunset but soon diverge. Southern hemisphere observers watch it slide towards the horizon throughout the month before disappearing by the last week but those in the north see it continue to rise higher until greatest elongation east on 9 July. After this, Mercury slowly descends towards the western horizon but it remains on view from the northern hemisphere throughout the month.
Venus
Location: Cancer -> Leo
The "evening star" makes for poor viewing in the northern hemisphere, never rising very high above the western horizon after sunset. However, it seems to leap upwards this month for southern hemisphere observers.
Mars
Location: Pisces
Rising around midnight, this reddish object is getting brighter despite not being fully illuminated for terrestrial observers (it reaches west quadrature on 12 July). It is highest in the sky just before dawn.
Jupiter
Location: Virgo
The king of the planets is setting just as Mars is rising. At east quadrature at the beginning of the month, this is an excellent time to observe Jupiter and its satellites through a small telescope.
Saturn
Location: Cancer
The ringed planet disappears from view early in the month and undergoes conjunction on 23 July.
Uranus
Location: Aquarius
This gas giant rises during the evening hours, approximately an hour after its solar system neighbour Neptune.
Neptune
Location: Capricornus
A small telescope will be necessary to see this distant planet after it rises mid-evening.
Pluto
Location: Serpens (Cauda)
With a brightness of around fourteenth magnitude, the smallest planet in the solar system can be seen only through a good-sized telescope. It can be seen for most of the night, setting just ahead of the Sun.

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...

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 image of the Sun in the SkyEye banner is courtesy of the SOHO/EIT consortium. The composite image from May 1998 combines EIT images from three wavelengths (171Å, 195Å and 284Å) into one that reveals solar features unique to each wavelength. SOHO is a project of international cooperation between ESA and NASA.

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