MOON WATCH NIGHT: Using A TElescope
The larger the lens or mirror on the telescope that you use, the
more detail you will see on the Moon.
This is what
you can view in binoculars.
To see what is
visible typically in a
Telescope, at
much higher resolution,
(2 km/pixel)
just click on the above image.
.
Do not get confused with magnification – this will let you see
things enlarged up in size, but too high a magnification will not help you to
see more detail.
Having a telescope on a tripod will really as the Moon will not
appear to wobble so much each time you touch the telescope, or when the wind
blows.
All the pictures shown on this page are with north towards the
top. In traditional astronomical telescopes, these invert the image so that
north is towards the bottom. In modern SCT type telescopes, the image is the
correct way up, but east and west are reversed. Please therefore be prepared
for differences in orientation or mirror images when you look through a
telescope!
Anyway, through a telescope, you should be able to see an amazing
amount of details, certainly beating what you can see in binoculars.
This part of
the Moon contains Plato crater, a lava flooded crater 109 km in diameter.
If you keep on
watching this crater you will see an amazing display of needle-like shadows
As the floor emerges into sunlight later in the night. There are
three bright mountain peaks
In this image – Mons Pico, Mons Pico Psi (both on the left) and
Mons Piton on the centre right.
To the right
of Mons Piton is the ringed crater Cassini, with two interior craterlets. Many
craters on the Moon are named after famous astronomers, scientists and
explorers.
You can also
see that most of the mountain peaks lie in an approximate arc – this is the
outer rim of the northern part of a huge 1123 km diameter Imbrium
impact basin. On the
right is the Vallis Alpes (Alpine Valley) a 166 km scratch possibly
caused by giant lumps of
rock thrown out by the formation of the Imbrium basin. This image is a
ALVIS simulation, and
you can generate similar views using the LTVT software.
The dark grey areas on the Moon are called mare, or former cooled
down pools of volcanic lava.
The lighter regions of craters are highland areas and are much
older. Many of these older craters contain other craters that have been formed on
top of them.
The south pole area of the Moon consists of highland terrain.
The crater with a central peak near
the top is 114 km in diameter and is called Moretus. Very
occasionally you may see stars off of
the limb of the Moon – depending upon where the stars or the Moon are
in the sky, the Moon
may occasionally occult (hide) these stars – the effect can be very
sudden, but is very impressive
to watch. Ice has been found in permanently shadowed craters near
the south pole and is pretty
ancient – possibly not having seen the light of day for a billion years
of more. This ice may have
come from debris thrown up from cometry collisions from the Moon in
the distant past, or
captured from gas clouds that the solar system passes through during its
journey around the Milky
Way galaxy. This image is a ALVIS simulation, and you
can generate similar views using the LTVT
software.
Notice as you
look towards the terminator you see more and more shadow. The terminator is
where the Sun-rises on the Moon, or where the Sun sets on the Moon. As the Sun
rises the shadows will shorten, and as the Sun sets the shadows will lengthen.
Astronomers used to use shadow lengths to work out how high
mountains are on the Moon. However spacecraft now allow more accurate
measurements using stereo images and Laser altimeters (LIDAR).
Rupes Recta, a
116 km linear fault on the Moon that is upto 300 metres higher on the eastern
side than on the west, though this varies along its length. To the
west of this lies a double
crater called Birt & Birt A - the larger of which is 17 km in
diameter. Further to the west, almost
onto the night side, you can see some wrinkle ridges or ancient lava
flows. This image is a
ALVIS simulation, and you can generate similar views using the LTVT software.
Notice that
some craters have central peaks, where as others do not. Craters
vary in appearance and smoothness. The smoothness increases with age as they
get battered by smaller impacts from meteorites.
The three main
co-joined craters here, from top to bottom are Theophilus, Cyrillus, and
Catherina, all
of which are just under 100 km in diameter. Because
these craters
lie further away from the terminator tonight, you see less shadow and
the
craters are lower in contrast. This image is a ALVIS
simulation, and you can generate
similar views using the LTVT
software.
Some craters have bright rays. These are ejecta debris material
thrown out from relatively young craters. The rays will darken with age over
millions of years.
What is the longest ray that you can see on the Moon and from
which crater does it originate?
Mare Crisium with a bright ray crater, Proclus (diameter 28 km),
on its western shore line.
Proclus has three
rays. When the sunrise/set terminator is near Proclus, the rays are not visible
–
therefore this ray material must not be very thick else it would cast a
shadow. If you look at the
crater closely, you will see that it is not circular, but polygonal in
shape. This image is a
ALVIS simulation, and you can generate similar views using the LTVT software.
Can you see colour on the Moon? For most people the answer will be
no, but for the very keen sighted, they may be able to detect faint hints of
colours in the mare areas, and indeed some people can see blue on Aristarchus
(though this crater will be invisible on Moon Watch Night).
Here is
another part of the Imbrium impact basin ring – the south east part, referred
to as
the Montes Appeninus. Apollo 15 in the foot hills of this area and
explored the Hadley Rille.
The rille is
just slightly west of the Montes Appeninus and there is a tiny bowl shaped
crater next to it. This image is an ALVIS simulation, and you can
generate similar views
using the LTVT software.
Webmaster: Dr Anthony Cook
Web version 2013/10/11
(Email: atc @ aber.ac.uk)