MOON
WWW.ASTRONOMY.COM 57
If you’re just starting
out, our natural
satellite makes a
tempting target in
the evening sky.
BY MICHAEL E. BAKICH
Explore the
AT FIR ST
QUARTER
THE MOON OFFERS LOTS OF VISUAL
TREATS when viewed through a telescope —
even a small one. With that in mind, let’s focus
on First Quarter. This phase is easy to observe
because it rises around noon and sets at midnight
(one hour later if daylight saving time is in effect),
so it’s visible throughout the evening. If you head
outdoors at sunset, just look due south.
1
Vallis Alpes is a cleft that bisects the Montes Alpes range. The valley
is narrow at both ends and wider along its middle. Look carefully
for small details here. Can you see that the southern face is straighter
than the northern side, which is slightly bowed and uneven? The more
rugged edges of the valley lie at the narrow west-southwest end that
cuts through the mountain range. ALL PHOTOS BY DAMIAN PEACH, UNLESS NOTED2
Cassini Crater lies at the eastern end of Mare Imbrium. The flooded
floor of the crater shows many impacts. The largest crater that sits
entirely within the rim is Cassini A, just northeast of center. A hilly ridge
runs from it to the southeast. Near the southwest rim is the smaller
crater Cassini B.