For about six weeks from the middle of July until the beginning of September, observers at southern and tropical latitudes will be able to spot planets Mercury, Venus and Jupiter towards the west just after sunset. During the visibility period the planets constantly change position with respect to each other. The diagram below shows the view looking west 45 minutes after sunset from July 22nd to September 10th from latitude 35S, approx. equal to Sydney, Cape Town and Santiago. From mid August, Jupiter at mag. -1.7 is a useful guide to locating much fainter Mercury. Brilliant Venus (mag. -3.9) also assists in locating Mercury during the last few days of August and into September. For comparison, Mercury fades from mag. -0.6 to +1.0 from July 22nd to August 31st.
On August 5th, the crescent Moon will be located in the same part of sky forming a spectacular evening sight for those lucky enough to be able to see it. Later in the month on August 27th a close conjunction occurs when Venus passes only 4 arc minutes north of Jupiter.
From mid-latitude Northern Hemisphere locations, Venus is visible from about mid-August and Jupiter until mid-August. Although Mercury reaches greatest elongation east on August 16th observers at these latitudes will struggle to glimpse the elusive World.
See also