If you like the website and want to contribute to the running costs then please do so below. All contributions are most welcome.

PayPal - The safer, easier way to pay online.


After reaching greatest eastern elongation at the start of last month, fast moving Mercury moves out west of the Sun hitting greatest western elongation on August 16. The elongation is 19 degrees but sadly not a good one regardless of observer's location. Northern hemisphere planet watchers have the best chance of glimpsing the illusive world. On August 16, Mercury (mag. 0.0) will appear only 7 degrees above the ENE horizon about one hour before sunrise. Unfortunately for southern hemisphere observers the angle is not favourable; the planet appears low down before sunrise and unlikely to be seen in the dawn twilight.


Like Mercury, Venus also reaches greatest western elongation this month when on August 16 it will be positioned 46 degrees from the Sun. As a result, the planet is a brilliant morning object, rising four hours before the Sun for northern temperate latitudes. For southern hemisphere observers the visibility is about an hour or so less. During the month, the magnitude of the planet decreases slightly from –4.5 to –4.3 with the phase increasing from 41% to 58%.

Venus is a brilliant morning object in August

Venus starts the month in Taurus. Unusually for planets, it then moves into the non-zodiac constellation of Orion, staying there between August 5 and August 13. At this time it will be located only twelve or so degrees north of first magnitude red supergiant star Betelgeuse. Venus then leaves Orion, spending the rest of the month in Gemini.

The waning crescent Moon will appear close to Venus on the morning sky on August 14.


Mars is visible in the early evening sky as soon as it gets dark but sets less than two hours after the Sun. The planet is located in Virgo with its rapid eastward motion carrying it past Saturn in mid-August. A good time to look is on August 14 when Mars (mag. 1.1) will pass between Saturn (mag. 0.9) and Spica (mag. 1.0). Look out for the contrasting colours; Mars will appear reddish, Saturn yellowish and Spica bluish-white.

Mars during August has an apparent diameter of only about 5.5 arc seconds.

Mars overtakes Saturn in August 2012

Mars overtakes Saturn in August 2012 - pdf format


Jupiter is now a brilliant morning object. The largest of all planets is located in Taurus and is currently moving closer to Earth. It starts the month at mag. –2.1 with an apparent diameter of 36 arc seconds and ends the month at mag. –2.3 with an apparent diameter of 39 arc seconds. The brightness and apparent size of Jupiter will increase until it reaches opposition in December.

The waning crescent Moon will appear close to Jupiter on the morning of August 12.


Saturn shines at mag. 0.9 this month and is located in the constellation of Virgo. The planet is visible as soon as darkness falls and is located just a few degrees north of mag. 1.0 star Spica. The month offers perhaps the last real chance with enough time to have a decent look at Saturn through a telescope. The planet has a good 16 arc seconds of apparent diameter and the rings are wide open, although Saturn now sets less than two hours after the Sun.

Mars is also in Virgo and starts the month to the west of Saturn. The red planets rapid eastward motion soon carries it towards and then past the much slower moving Saturn.


Uranus is located in the constellation of Cetus and is now well placed in the late evening / morning sky. It rises before midnight at the start of the month. The distant planet is only one degree east of star 44 Piscium, which at mag. 5.8 is almost equal in brightness.


Neptune reaches opposition on August 24 and is visible all night. It is located in the constellation of Aquarius and only three degrees south of mag. 4.2 star Ancha (theta Aquarii). At mag. 7.8, Neptune is not visible to the naked eye but quite an easy binocular target.

Solar System Data Table August 2012

 DateRight AscensionDeclinationMag.SizeIllum. (%)Distance (AU)Constellation
Sun5th Aug 201209h 01m 47.8s16d 54m 46.9s-26.731.5'1001.014Cancer
Sun15th Aug 201209h 39m 42.6s13d 59m 05.0s-26.731.6'1001.013Leo
Sun25th Aug 201210h 16m 45.5s10d 41m 10.0s-26.731.6'1001.011Leo
Mercury5th Aug 201208h 13m 10.3s15d 44m 59.3s3.010.2"070.659Cancer
Mercury15th Aug 201208h 24m 06.8s17d 51m 23.7s0.107.8"360.864Cancer
Mercury25th Aug 201209h 18m 27.6s16d 37m 46.1s-1.006.0"751.126Cancer
Venus5th Aug 201205h 50m 26.6s19d 28m 53.0s-4.526.6"440.626Orion
Venus15th Aug 201206h 29m 11.3s19d 58m 00.0s-4.423.7"500.705Gemini
Venus25th Aug 201207h 11m 17.5s19d 50m 56.0s-4.421.3"550.782Gemini
Mars5th Aug 201213h 07m 41.0s-07d 22m 29.0s1.105.7"901.652Virgo
Mars15th Aug 201213h 30m 28.8s-09d 47m 56.2s1.105.5"911.711Virgo
Mars25th Aug 201213h 54m 20.5s-12d 11m 08.9s1.205.3"911.767Virgo
Jupiter5th Aug 201204h 37m 55.5s21d 18m 45.1s-2.236.4"995.415Taurus
Jupiter15th Aug 201204h 44m 29.1s21d 30m 47.0s-2.237.4"995.276Taurus
Jupiter25th Aug 201204h 50m 08.5s21d 40m 12.8s-2.338.4"995.130Taurus
Saturn5th Aug 201213h 32m 47.4s-07d 06m 25.6s0.916.6"10010.034Virgo
Saturn15th Aug 201213h 35m 21.0s-07d 23m 44.0s0.916.3"10010.186Virgo
Saturn25th Aug 201213h 38m 22.7s-07d 43m 24.2s1.016.1"10010.326Virgo
Uranus5th Aug 201200h 31m 48.3s02d 37m 40.9s5.803.6"10019.472Cetus
Uranus15th Aug 201200h 31m 02.3s02d 32m 28.3s5.803.6"10019.343Cetus
Uranus25th Aug 201200h 30m 02.0s02d 25m 46.8s5.803.7"10019.235Cetus
Neptune5th Aug 201222h 17m 53.4s-11d 14m 29.2s7.802.4"10029.036Aquarius
Neptune15th Aug 201222h 16m 53.7s-11d 20m 16.8s7.802.4"10028.996Aquarius
Neptune25th Aug 201222h 15m 51.5s-11d 26m 14.7s7.802.4"10028.984Aquarius