What's Up in September

September is the month for planet-gazers. We've got all the details for when and where to see the planets this month.

On September 8, enjoy the nearly full Moon near Saturn in the eastern sky rising around sunset and visible all night long. Just a few days later, the Moon will reach full phase on September 10 - rising at sunset and setting at sunrise. The September full moon is called the Harvest Moon because it occurs in the fall when crops are ready to be harvested in preparation for the long winter season.

By the following night, September 11, the Moon will move close to Jupiter in the sky. Look for them rising in the northeast about 30 minutes after sunset. If you have a pair of binoculars or a small telescope, you can look for the Galilean moons - Jupiter's four largest - orbiting around the king planet. Jupiter will reach opposition, the point in its orbit when it is opposite the Sun in the sky from our viewpoint, on September 26.

A week later, on September 16, the last quarter Moon will be near Mars, rising in the late evening. Over the coming season, Mars will get brighter as it approaches opposition in early December. 

Those with telescopes and dark skies are encouraged to look for Neptune in mid-September because it will be at its closest, and therefore brightest, in the sky. Neptune reaches opposition on September 17. Be aware that even with a mid-size amateur telescope with high magnification, Neptune will only appear as a tiny disc in the eyepiece.

Finally, we mark the changing of the seasons on September 22 when we reach the fall equinox. The Earth's rotation axis is perpendicular to the Earth-Sun line, causing the Sun to rise due East and set due West and the length of day and night are nearly equal. From September 23 on, the days will get shorter as we approach the official start of winter on December 21.

No matter when you head outside to gaze at the stars, we wish you clear skies!