Early risers Saturday morning had a delight with Jupiter, Venus and the Moon forming a triangle in the eastern sky. However, for those who missed it, and the even more spectacular conjunction last week when Jupiter and Venus appeared so close they could be seen in the same field of view of a small telescope, there is still another event to look out for, at a much more civilized time.
Just as Jupiter and Venus have been having a close approach in the morning sky, Mars and Saturn have been lining up in the early evening. Although not nearly as bright as their morning counterparts, the Mars-Saturn conjunction has a few other things in its favor, besides the fact that you don't have to get out of bed at 5am to see it.
For a start the two planets have a third neighbor from our perspective. Antares, the brightest star in Scorpio looks as though it is quite close to the planetary pair (of course it's actually hundreds of thousands of times further away). Antares isn't just a very bright star. Its name comes from the Greek anti Ares, or “The Rival of Mars”, for its deep red hue. Now is a great opportunity to compare the colors, with Saturn's golden shades for contrast.
On Saturday a triangle was formed in the early morning sky as Jupiter and Venus, moving apart from their exceptionally close approach on Monday, were joined by the crescent Moon. On Sunday 31st and Monday 1st of September the Moon will have swung across the sky to join the evening show.
The exact alignment will depend on where you are in the world, but from the right spot there will be an almost straight line from Antares to Mars, Saturn and finally the Moon. The following day a trapezoid will be formed between the four. On its way through the Moon will pass less than half a degree from Saturn and, six hours later, it will drift just over 4 degrees past from Mars. Although not as bright as Jupiter and Venus, Mars and Saturn will still be among the most visible objects in the sky and, along with Antares, should be easy to spot in the west even with polluted skies. Under slightly darker surrounds the other stars of Scorpio should reveal the scorpion's distinctive shape around Antares.
Museum of Victoria/Stellarium. Even before the Moon joins Mars and Saturn in the sky the pair will be putting on a show.