September 2012 guide to the five visible planets

You can easily find four planets in September 2012. You’ll still find two in the evening sky –Mars and Saturn – if you look soon enough after sunset. The two much brighter planets –Venus and Jupiter – are very bright and prominent in the sky before dawn.

The evening planets, Mars and Saturn, are slowly sinking into the glare of evening twilight, so it’ll take a deliberate effort to spot them after sunset this month, especially from northerly latitudes. You’ll need eagle eyes and possibly binoculars to catch the moon with Saturn onSeptember 18 and with Mars on September 19.

As for the morning planets in September 2012, you’ll have no trouble seeing Venus andJupiter – the sky’s brightest and second-brightest planets, respectively. Venus continues to dazzle us in the eastern predawn darkness and morning twilight. From mid-northern latitudes, Venus will rise around 2 a.m. (3 a.m. local daylight saving time) in early September and only about one-half hour later by the month’s end. Jupiter will rise around 11 p.m. local time (12 midnight local daylight saving time) in early September and by about 9 p.m. local time (10 p.m. local daylight saving time) by the end of the month. Jupiter and Venus rise later at more southerly latitudes, so check out the links on our almanac page for the precise rising times in your part of the world.

Jupiter (left) with several of its moons near Earth’s moon (right) on the morning of September 8, 2012. Photo by EarthSky Facebook friend VegaStar Carpentier in Paris. Click here to expand this image.

More on the morning planets: Jupiter and Venus

Venus and Jupiter rise well before the sun in the morning sky all through September. People around the world have been watching these worlds and marveling at their brightness in the morning sky ever since late June and early July 2012. If you haven’t seen them yet, you are really missing out on a fine morning attraction. Venus reached greatest brilliancy around mid-July 2012, but it is still very bright – always the brightest object in Earth’s sky besides the sun and moon. And Jupiter will be brightening – and rising earlier each night – throughout September. Before long, Jupiter will have shifted over into the evening sky. By early December, when Earth will pass between Jupiter and the sun, this bold planet will shine in our sky all night long.

Whereas Jupiter shines in front of the constellation Taurus all through September 2012, Venus starts out in the constellation Gemini the Twins. These two planets quickly part company in the September morning sky. Jupiter stays rather close to the bright starAldebaran throughout the month, but Venus starts out September near the Gemini starsCastor and Pollux and ends the month near Regulus, the brightest star of the constellation Leo.

Here is Venus (upper right) and the very old moon on the morning of September 14, 2012, as seen by EarthSky Facebook friend VegaStar Carpentier in Paris. The moon put on a fine show from about September 7 to September 14, passing the bright stars and planets Venus and Jupiter in the predawn sky. After mid-September, the moon will return to the evening sky. Click here to expand this image.

Jupiter and its moons as seen on August 15, 2009

In other words, Venus passes all the way through the constellation Cancer the Crabin September 2012. You may want to set your alarm clock to see the waning crescent moon pairing up with Venus and Cancer’s Beehive star cluster before dawn on Wednesday, September 12. Look for another fine showing of the moon and Venus (and the star Regulus) before dawnSeptember 13.

September 2012 should be great for telescopic observations of Jupiter. With only a modest backyard telescope, you can easily see Jupiter’s four major moons – Io, Europa, Ganymede and Callisto.