The moon waxes in the evening sky this week, with first-quarter occurring on the 22nd. That day has been dubbed International Observe the Moon Night. Astronomers, educators and sky enthusiasts from around the world have set the date to encourage people to appreciate our only natural satellite. For teachers, students or the curious, log onto www.observethemoonnight.org for events, activities and moon-related topics. Or simply take a moment to gaze at this wonder, and give a wink in honor of Neil Armstrong.

The moon wanes to new phase Saturday the 15th. While you may be able to see a razor-thin cresecent low in the east before sunrise Friday, the moon won’t reappear until Tuesday, low in the west for less than an hour after sunset. But given the chance, you’ll want to catch it, forming a wide obtuse triangle with Saturn slightly higher to the right and Mars higher still to the left. The next night, the scene repeats itself, except the growing moon is now the highest point of the three.

Before dawn Friday morning, the moon appears just a few degrees ahead of the orange star Aldebaran, the fiery eye of Taurus the bull. To either side of the moon, you’ll find the two brightest star clusters. To the east is the Y-shaped Hyades cluster, or the face of the bull. To the moon’s west is the Pleiades cluster, or the seven sisters, which marks the bull’s shoulder.

Friday morning marks August’s second full moon, a blue moon. While the term blue moon dates back hundreds of years, its meaning of the second full moon in a single month was crafted in the 20th century. Its early usage you might hear in the phrase I’ll believe that when the moon is blue.

Thursday and Friday offer the best chance to track down the only planet never visible to the unaided eye: Neptune, the most distant planet in the solar system since Pluto’s demotion to planetoid status several years ago.

Of the 88 official constellations over our heads, nearly half are animals, serpents, birds and fishes. Admired for their beauty or feared for their strength, these are wild creatures, beasts you wouldn’t want to encounter, let alone have in the house. In fact, of them all, only a few are domesticated animals. One of the oldest recognized constellations is Taurus the bull.

The moon reaches last-quarter Thursday, rising around midnight. Look for the faint lights of the Pleiades star cluster, marking the back of Taurus the bull, 10 degrees above the moon.     The next night, or rather morning, the moon rises near 1am, now just scant degrees from Aldebaran, the red heart of the bull, and Jupiter, forming a tight triangle. Brilliant Venus trails this pack by about 20 degrees.

Thursday’s full moon brightens the sky from dusk till dawn. American Indians called this the sturgeon moon, as it marks the time when these great fish once began their migration and were most easily caught. Sturgeon have been plying our waters for more than 150 million years, yet today most species are endangered.     More common names for August’s full are the grain moon, the lightning moon, the green corn moon and the red moon.

A gibbous moon waxes through afternoon and evening skies this week. Friday the moon, just past first quarter, is low in the southwest after sunset, with fiery Antares, the heart of Scorpius, trailing less than 10 degrees behind.

Thursday’s new moon leaves weekend skies bereft of excess light, highlighting the backdrop of stellar lights.