Not quite the Harvest Moon

Plus, all five visible planets in one day!


With a clear view of the eastern horizon, early morning viewers might catch three planets in the sky at once, near each other, with Venus dominating them all.

It’s easy to spot Venus, now the brilliant Morning Star in the east before sunrise. (Those bright stars to its right are the winter stars Procyon and Sirius). At around 5:30 am, look straight down from Venus. In the faint glow of the rising sun, and maybe you’ll need binoculars, you’ll see huddled together Mars, Mercury and the star Regulus in Leo.

Keep watching the morning sky for Mercury, as this planet nearest the sun will reach its highest point above the horizon in the morning sky on Sept. 12.

All five visible planets appear in the sky for the next two weeks, but catch them soon. In the evening, Jupiter is rapidly slipping from view as it sets shortly after sunset. Look for Jupiter just over the western horizon around 8:30 pm, close to the star Spica to its lower left. In the south, Saturn glows gold after sunset, to the upper left of the bright red star Antares, the heart of Scorpius the Scorpion.

Full moon Tuesday While the moon will appear full as it rises Tuesday, Sept. 5 at sunset, it’s not truly full—that is, directly behind Earth from the sun— until 2:04 am the next morning.

This is the third and final full moon of the summer for the Northern Hemisphere and is known as the Full Corn or Barley Moon. Some might mistake it for the Harvest Moon, which is defined as the full moon nearest to the autumn equinox and often occurs in September. But this year, the full moon on Oct. 5 is nearest to the Sept. 22 autumnal equinox.

Yet, the full moons of September and October 2017 are similar and can be thought of as co-Harvest Moons. The Harvest Moon is special in large part because it seems to be full three nights in a row, appearing shortly after sunset as full moons do. Normally at our latitude, the moon rises about 50 minutes later every day, but near the fall equinox it rises only 35 minutes later each night. Therefore to the casual observer the moon appears “full” over two or three nights.

There’s often a fair amount of humidity this time of year causing turbulence in the air so check out the color of the full or near-full moon. It likely will appear a beautiful gold or orange color as it rises in the east at sunset. Happy viewing.