Plato's Hook: a hook like effect in one of the shadow spires in Plato,
near a rim - this is a Clair-Obscur effect. It was first seen by
H.P.Wilkins in 1952. Clair-Obscur have no scientific importance and
are just tricks of the light that make us think we see something
like a letter of the alphabet or a shape or face. Clair-Obscur
effects are scientifically pointless to observe. However, if you want
to be thrilled, or obtain an image to impress someone then give them
a go. If you do observe, or image this, by all means send your
observation into ALPO or the BAA, but we probably won't publish,
but will nevertheless retain in our archives, just in case
features elsewhere in the image are of interest to future
researchers.
BAA Request: How early can you see the central peak of this
crater illuminated by scattered light off the crater's west
illuminated rim? High resolution and/or long exposures needed
to capture detail inside the floor shadow. All images should
be sent to me on the email adrress below, whether or not you
were successful in capturing the central peak:
a t c @ a b e r . a c. u k
BAA Request: Any sign of colour on this crater? Exmaine it
through red and blue filters e.g. Wratten 28 and 44A. Also
would you say that the crater looks dull? We are especially
interested if you observe the cxrater under poor transparency
conditions. All observations, including visual descriptions,
sketches, or images should be emailed to:
a t c @ a b e r . a c. u k .
ALPO Request: Can you detect any colour, inside the crater, on
the floor and elsewhere? Can you image any colour? Minimum
telescope aperture needed: 6", and if possible try using a
refractor. All images or sketches should be sent
to me on this email adrress: a t c @ a b e r . a c. u k
BAA Request: Aristarchus area - We are trying to explain an
observation from Meudon Observatory in France made in 1881 of
a bright rope-like effect seen in the vicinity of this crater.
Please send any images to: a t c @ a b e r . a c. u k .
ALPO Request: Can you see a darkening on the northen floor of
this crater? All visual reports, sketches or color images should
be emailed to:
t o n y . c o o k @ a l p o - a s t r o n o m y . o r g
BAA Request: In 1991 Dec 23 Bob Mizon (BAA) sketched the
crater Cleomedes and Mare Cisrium. In the floor of the shadow
filled Cleomedes was an dusky oval area - presumably the last
rays of the Sun reaching the floor. We would like yuo to
either sketch, or image, over time, how the shape of this oval
area changes, and eventually vanishes. How late in terms of
colongitude can it still be seen? Is there any hint of colour
present? Telescopes of aperture 6 inche or larger should be
used. Please send any observation
you make to:
a t c @ a b e r . a c . u k
BAA Request: Sketches or images needed of Toricelli B - of
sufficient resolution to reveal shadow. All observations,
including sketches or images shouild be emailed to:
a t c @ a b e r . a c. u k .
BAA Request: Cyrillus. There is a small white craterlet just
north of the three central peaks. We are interested to receive
high resolution images of this in order to find out at what
selenographic colongitude, in the lunar evening, that it loses
it's white spot appearence. Please use scopes largher than 6
inches in diameter.
Please email these to: a t c @ a b e r . a c . u k
These can only be observed using low-light level cameras running at 25 frames per sec,
or faster, and capable of recording 9th or 10th magnitude stars in real time.
Dates/UTs of observing runs, or detections of impacts, should be emailed to:
ALPO - email: c u d n i k @ s b c g l o b a l . n e t
BAA - email: a t c @ a b e r . a c . u k
UAI - email: a m . 5 4 8 5 2 @ g m a i l . c o m
These can only be observed using low-light level cameras running at 25 frames per sec,
or faster, and capable of recording 9th or 10th magnitude stars in real time.
Dates/UTs of observing runs, or detections of impacts, should be emailed to:
ALPO - email: c u d n i k @ s b c g l o b a l . n e t
BAA - email: a t c @ a b e r . a c . u k
UAI - email: a m . 5 4 8 5 2 @ g m a i l . c o m
These can only be observed using low-light level cameras running at 25 frames per sec,
or faster, and capable of recording 9th or 10th magnitude stars in real time.
Dates/UTs of observing runs, or detections of impacts, should be emailed to:
ALPO - email: c u d n i k @ s b c g l o b a l . n e t
BAA - email: a t c @ a b e r . a c . u k
UAI - email: a m . 5 4 8 5 2 @ g m a i l . c o m
These can only be observed using low-light level cameras running at 25 frames per sec,
or faster, and capable of recording 9th or 10th magnitude stars in real time.
Dates/UTs of observing runs, or detections of impacts, should be emailed to:
ALPO - email: c u d n i k @ s b c g l o b a l . n e t
BAA - email: a t c @ a b e r . a c . u k
UAI - email: a m . 5 4 8 5 2 @ g m a i l . c o m
These can only be observed using low-light level cameras running at 25 frames per sec,
or faster, and capable of recording 9th or 10th magnitude stars in real time.
Dates/UTs of observing runs, or detections of impacts, should be emailed to:
ALPO - email: c u d n i k @ s b c g l o b a l . n e t
BAA - email: a t c @ a b e r . a c . u k
UAI - email: a m . 5 4 8 5 2 @ g m a i l . c o m
These can only be observed using low-light level cameras running at 25 frames per sec,
or faster, and capable of recording 9th or 10th magnitude stars in real time.
Dates/UTs of observing runs, or detections of impacts, should be emailed to:
ALPO - email: c u d n i k @ s b c g l o b a l . n e t
BAA - email: a t c @ a b e r . a c . u k
UAI - email: a m . 5 4 8 5 2 @ g m a i l . c o m
BAA Request: We need colour images of Earthshine, including the
approximate area in the vicinity of Santbech crater. You can use
a telescope with an aperture of 3" of larger (if possible use a
refractor). This is to see what effects in our atmosphere, or
telescope optics, can replicate some glows seen visually back in
1994. Any images should be emailed to:
a t c @ a b e r . a c. u k .
These can only be observed using low-light level cameras running at 25 frames per sec,
or faster, and capable of recording 9th or 10th magnitude stars in real time.
Dates/UTs of observing runs, or detections of impacts, should be emailed to:
ALPO - email: c u d n i k @ s b c g l o b a l . n e t
BAA - email: a t c @ a b e r . a c . u k
UAI - email: a m . 5 4 8 5 2 @ g m a i l . c o m
Monte Caucasus: "shadow face" silhouette Clair-Obscur effect.
Clair-Obscur effects have no scientific importance just tricks
of the light that make us think we see something like
a letter of the alphabet or a shape or face. Clair-Obscur
effects are scientifically useless to observe. However, if
you want to be thrilled, or obtain an image to impress someone
then give them a go. This effect on the southern end of Montes
Caucuses looks like the side silhouette of a cartoon human face.
We are still slightly undertain about the precise colongitude
range, so if you do not see the face, try again later. If you
do observe, or image this, by all means send your observation
into ALPO or the BAA, but we probably won't publish, but will
nevertheless retain in our archives, just in case features
elsewhere in the image are of interest to future researchers.
Note that we have some uncertainty in the colongitude range
- so if you don't see it, please tells us the date and UT so
we can make some improvements in the predictions.
These can only be observed using low-light level cameras running at 25 frames per sec,
or faster, and capable of recording 9th or 10th magnitude stars in real time.
Dates/UTs of observing runs, or detections of impacts, should be emailed to:
ALPO - email: c u d n i k @ s b c g l o b a l . n e t
BAA - email: a t c @ a b e r . a c . u k
UAI - email: a m . 5 4 8 5 2 @ g m a i l . c o m
These can only be observed using low-light level cameras running at 25 frames per sec,
or faster, and capable of recording 9th or 10th magnitude stars in real time.
Dates/UTs of observing runs, or detections of impacts, should be emailed to:
ALPO - email: c u d n i k @ s b c g l o b a l . n e t
BAA - email: a t c @ a b e r . a c . u k
UAI - email: a m . 5 4 8 5 2 @ g m a i l . c o m
ALPO Request: Try viewing the central peak through a red and
blue filter e.g. Wratten 25a and 38, and comparing the
brightness to the of the eastern sunlit rim. Does the size
of the central peak change between filters? If you do detect
colour here, obviously check for colour on other central
peaks. If taking colour images, make sure that you do
nderexpose slightly so as to avoid saturating the central
peak. All visual reports, sketches or colour images should be
emailed to:
t o n y . c o o k @ a l p o - a s t r o n o m y . o r g