[4] The floor of Clavius is littered with
smaller craters.
[5] Crater Plato has a smooth floor
pitted with craterlets.
[6] The impressive ray crater
Copernicus with its terraced walls and
central mountain peaks.
[7] The far side of the Moon
photographed by the astronauts
on board Apollo 16.
Small craters are often bowl shaped and they too may have central peaks,
though in no case does a central peak surpass the height of the highest
mountains on the wall. Many craters have been so distorted by impacts that
they are barely recognizable. For instance, Stadius, near Copernicus, once a
noble formation, now almost classifies as a ghost.
Plato is another famous crater, in the north of the Moon, which appears
as an ellipse even though it really is a circular crater 60 miles across. The
walls are of modest height, and there is no central mountain and very little
detail on the floor. It is one of the flattest parts of the entire Moon. It is also
very dark grey so Plato is highly recognizable whenever it is in sunlight. An
even darker-floored crater is Grimaldi on the Moon's west limb as seen from
Earth. It is larger than Plato though less regular, and with a floor so dark it is
impossible to overlook whenever it is in sunlight.
The far side of the Moon, invisible from Earth, is also mountainous and
cratered, though there are differences in detail. There are mountains, seas
and plenty of craters of all kinds. From this part of the Moon the Earth can
never be seen because it always remains below the horizon.
It is amazing how quickly a lunar crater alters appearance according to
the angle at which the Sun strikes it. A large walled plain is magnificent at
sunrise, for example when shadow covers half of the floor, though under full
illumination it may be hard to identify. Full Moon is the worst time to begin
observation, with sunlight coming straight down giving no shadows. The best
views are obtained when the phase is crescent, half or gibbous. The Moon
may be changeless now, and certainly major upheavals belong to the distant
past, but observers have reported indications of temporary localized glows
or obscurations known as TLP (Transient Lunar Phenomena), a term for
which PM was responsible.
The cause of these mild activities is a matter for debate, but disturbance
of dust in the outer layer may be involved. TLP are not volcanic. Active
vulcanism died out a long time ago.
It is fascinating to take a crater and draw it from night to night under
different conditions. The differences are striking. There is tremendous scope
here for the astronomical photographer and one does not necessarily need
an expensive camera.
When seen in the night sky, the Moon appears bright and quite dominant
compared to the fainter stars and planets. During the day, if the Moon
happens to be above the horizon at the same time as the Sun, its appearance
is more subdued, the surrounding blue sky swamping its light, making it
harder to pick out.
The Moon can also occupy the transition zone between these two
periods: dawn and dusk. All of these conditions provide opportunities for
capturing the beauty of the Moon with a camera and as we’ll see below,
each requires a slightly different approach.
We’ll start by discussing general lunar photography with a photographic
digital camera. The brightness of the Moon at night is often sufficient to
allow your camera’s automatic setting functions to work. Under these
circumstances, set the camera to automatic, point it at the Moon and press
the shutter button. The chances are that the photo you get back may not be7Our friendly Moon