Last Saturday's new moon signaled the start of a new lunar cycle. Our closest neighbor in space started moving east, away from the sun, and a very young wafer-thin crescent moon can be seen tonight and Tuesday evening just above the western horizon 30 minutes after sunset.

This week, the waxing crescent will continue to move through the ecliptic, move higher in the western sky and pass under Saturn and Virgo's brightest star, Spica.

Look for the 4-day-old crescent moon Wednesday evening at 9:30 p.m., 7 degrees below Saturn. By Tuesday evening, the moon will have moved about 15 degrees to the east and sit just below Spica. As the moon continues its eastward trek this week through Virgo, it will wax to first-quarter phase by Saturday night in Libra.

If the sky is clear Monday and next Tuesday evening, it may be possible to see the entire dark disc of the moon faintly illuminated as well. This phenomenon is possible because of earthshine.

First Published: August 1, 2011, 8:00 a.m.