Gilbert Rotary Centennial Observatory
- In the Sky for August 2017 -

Source: EVAC August Newsletter

The Moon & Planets: 

  • On Tuesday, August 1, it is a good time to look at the lunar crater, Clavius, as libration has tipped that part of the Moon toward us. It is a big crater, located in the southern part of the Moon, near the terminator and has an arc for decreasing sized craters in it.

  • On Monday, August 7, at 7:33 PM the full Moon rises spoiling any chance of hunting for faint fuzzies for the night.

  • On Tuesday, August 15, the Moon is at third quarter phase and rises at 12:41 AM (Wednesday).

  • On Sunday, August 20, before midnight, three of Saturn's brightest moons are all on the celestial west of the planet. They are (starting with the furtherest) Titan (magnitude 9.2), Rhea (magnitude 10.4), and Dione (magnitude 11.2).

  • On Monday, August 21, it is new Moon and you have all night to hunt for faint fuzzies. At 9:12 AM a partial eclipse of the Sun begins in Prescott. It is maximum about 10:30 AM (about magnitude .75). The show is over at 11:59 AM. For a total eclipse, you need to travel. The path of totality starts in Oregon and exits in South Carolina. Sky and Telescope, and Astronomy have articles about the eclipse this month. Your favorite search engine will produce more sites than you need. Many companies will sell you eye protection which you will need for the partial phases. It is already too late to get reservations in the eclipse path, but you might get some in driving distance of the path. Remember: you will need eye protection when any part of the photosphere (the bright part of the Sun) is showing unless you use a pin hole camera to project an image of the Sun. You must not use a filter during totality if you want to see anything (and you will want to see something).

  • On Monday, August 28, at 11:31 PM, the rst quarter Moon sets.

Evening Planets (after sunset): 

  • Mercury, W
  • Jupiter, W
  • Saturn, S
  • Neptune, E

Morning Planets (before sunrise): 

  • Neptune, SW
  • Uranus, S
  • Venus, E

Phases of the Moon: 

Phase Date Time Current Moon Info
Full Moon August 7 2:30 pm MT

Description: Description: Description: Description: Click for Gilbert, Arizona Forecast

Last Quarter Moon August 14 9:15 pm MT
New Moon August 21 2:30 pm MT
First Quarter Moon August 29 4:13 am MT


There are no comets brighter than magnitude 8 visible this month.


The Perseid meteors peak on August 12. For viewers in North America, they will be best after midnight on the nights of the 11th - 12th and 12th -13th. Unfortunately, the Moon, five days past full, will interfere and wash out the fainter meteors. This shower can produce rates of over 100 meteors per hour under ideal conditions; this year you may have to settle for 20 - 30 per hour.