• August's trio of Spica, Saturn and Mars is joined by the waxing crescent moon this evening. Look in the west after sunset for the crescent moon and the three bright celestial objects forming a triangle next to it.
• This grouping of three objects - Spica, Saturn and Mars - places them at about about five degrees apart of each other. You can estimate how close they are with your hand. Your fist held at arm's length is ten degrees, three fingers is six degrees, your pinky finger about one degree. In Anarctica and New Zealand Spica will be occulted -- or covered -- by the moon.

• In ancient Greek "planet" means "wanderer" and throughout August Saturn and Mars have indeed wandered the sky around Spica. As they move in their orbits around the sun, these planets have shifted in their position in the sky. Saturn takes 29.4 Earth years to orbit the sun and we observe it move only 12.22 degrees across the ecliptic in one year (information from the Royal Astronomical Society of Canada Observer's Handbook). Saturn has remained near Spica throughout the year. Mars on the other hand takes only 1.88 Earth years to orbit the sun. We can easily notice how it moves against the faraway background stars.
• So step outside this evening and enjoy the grouping of four bright celestial objects: the moon, the planets Saturn and Mars and the star Spica.
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