As darkness falls around the world on August 30, 2014, look for the star Spica to the west (right) of tonight’s waxing crescent moon (outside of the above sky chart). Meanwhile, the planets Mars and Saturn shine to the east (left) of tonight’s moon. Remember, west is in the direction of sunset.
Yesterday, on August 29, the moon paired up with Spica, as shown on the chart below.
The illuminated side of the waxing crescent moon can help you to figure direction. Because the “horns” of the waxing moon point away from the setting sun, the horns point eastward. Moreover, the moon travels eastward through the constellations of the Zodiac, moving its own diameter (1/2 degree) eastward per hour.
One day later, as darkness falls on August 31, notice how much the moon has moved toward the planets Mars and Saturn. (See sky chart at top.)
Because of the Earth’s rotation on its axis, the moon, planets and stars all sink westward throughout the evening hours. Even so, the moon – as always – moves eastward in front of the backdrop stars of the Zodiac.
This evening, on August 30, the moon is east of Spica, the brightest star in the constellation Virgo, yet west of the planets Saturn and Mars.