In September 2007, the moon hides part of the sun early in the month and rises as the fall Harvest Moon later in the month. During New moon on September 11 a partial solar eclipse occurs for observers in South America. The moon begins covering part of the sun at 10:25 UT and ends at 14:36 UT. For observers outside of the eclipse zone, see which of the nights following September 11 that you can first spy the thin crescent moon as it sets in the west around sunset. This month, Muslims mark the beginning of Ramadan with the first sighting of the young crescent moon. A couple weeks later, on September 26, the Harvest Moon rises in the east at sunset. Full Moon occurs at 3:45 pm EDT.
The dominant planet in September 2007 is Jupiter, which currently looks like a bright star low in the south. At magnitude -2.2, Jupiter is the brightest object in the evening sky this month besides the moon. The bright star below Jupiter is Antares at magnitude 1. Jupiter is in the constellation Ophiuchus and Antares is in the constellation Scorpius. On September 17 a waxing moon joins the duo.
Late in the evening this month, Mars will rise above the eastern horizon as a reddish dot. On September 4, a quarter moon joins Mars in the early morning hours. Mars lies about 35 million miles from Earth, so despite what you may have heard, it is impossible for the Red Planet to ever appear as large as a full moon in the sky for inhabitants on Earth.
The brilliant Venus, which had shone brilliantly in the evening sky all year, is now dazzling observers in the morning sky. It reaches its maximum magnitude of -4.5 for the year on September 23. Venus is joined by Saturn, which lies just below and shines at magnitude 0.5. The bright star in this grouping of planets that currently lies close to Saturn is Regulus, the heart of Leo the Lion.
Mercury is at its best for the year in the middle of September, but even then it is a very poor apparition of the planet. If you want to find it, you will have to look low in the west-southwest after sunset with a pair of binoculars. Another planet at its best for the month is Uranus, which reaches opposition on September 9. At magnitude 5.7, it will be visible all night to give you lots of opportunities to track it down. Uranus is currently in the constellation Aquarius.
The first day of fall is at 5:51 am EDT on September 23. This marks the autumnal equinox. On the equinox, you can find the cardinal directions without a compass because the sun rises directly in the east and sets directly in the west. All month you will notice that the sun sets a little farther south each day, ushering in shorter days and cooler weather. Read more about the equinox and whether or not you can balance an egg on this day.
The return of the Pleiades star cluster to the evening sky is another sign of fall for stargazers. Binoculars give the best view of this cluster, resolving its six naked-eye stars into hundreds. On September 2 the moon occults some of the stars in the Pleiades. The Pleiades is in the constellation Taurus.
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