The Sky Tonight

THE PLANETS

August and September 2008 - by Chris Marr

Mercury
Those who enjoyed the grouping of Saturn, Mars and Regulus during June and July will be pleased to know that Mercury and Venus will be joining the ringed-planet in Leo in the early evenings during August for a series of close encounters. Mercury and Venus will then move on to Virgo to interact with Mars during September, with the bright star Spica completing a beautiful naked eye grouping. The thin sliver of a Moon will be joining in the grouping on 2 September.

Venus
As mentioned above, Venus is now in the evening sky and will be close to Mercury, Saturn and Regulus during most of August, and then close to Mercury, Mars and Spica during most of September. With all of these interactions, Venus will be the brightest of the objects. On 18 September the four objects will be doing their own representation of the Southern Cross.


Earth
The Earth is at its vernal equinox on 23 September. Starting in the wee small hours of 17 August, there will be a partial lunar eclipse, so if that’s your interest, set the alarm and get ready by about 2.23am to watch the Moon slowly drift into the Earth’s shadow. While you’re watching the event, keep a close eye out for Neptune, which will be right at the edge of the Moon at that time. An occultation by the Moon of the Beehive cluster (M44) takes place on 25 September. Unfortunately, the Moon will be just halfway across the cluster when dawn ruins the view

Mars
Mercury and Venus catch up with Mars as it closes on Spica during September in Virgo, making for an interesting grouping. On 4 August, Mars will be joined by a thin sliver of Moon.

Jupiter
Jupiter can be spotted in Sagittarius during this period, drifting slowly backwards until 8 September when it stops dead. From then on it reverts to normal motion through the heavens. The Moon will be seen close to the gas giant on 13 August and again on 9-10 September.

Saturn
August will be your last chance to view Saturn in the evening sky for a while. It is slowly slipping down to pass behind the Sun on 4 September and will reappear as a pre-dawn object later in September. As mentioned earlier, before it departs it will create some beautiful gatherings with Mercury and Venus in Leo. On 3 August, a 2-day Moon passes close by.Uranus.

Uranus
Uranus remains in Aquarius for this period and will be at opposition on 13 September. As is often the case, planets at opposition are at their brightest, but in the case of Uranus this is still only magnitude 5.7, so still hard to spot. Nevertheless, it won’t be getting any brighter, so catch it while you can.

Neptune
Neptune is at opposition on 15 August, and spends this period roaming through Capricornus. As mentioned above, it will be brushing past the edge of the Moon in the early hours of 17 August while the Moon is partially eclipsed, so see if you can spot it. It will be very close to the Moon again on 13 September.

By Chris Marr
[Information Source : "Astronomy 2008" by Glenn Dawes, Peter Northfield and Ken Wallace]

Constellations

Have you ever wondered when a particular constellation will be visible? Check the culmination dates for the constellations, which are given for 2100 local time. Also included in this list are their common and genitive names, and their officially recognized abbreviations. These dates are valid world-wide, but not all constellations will be visible from all latitudes.