⃝2012 05 lsc

The British Astronomical Association

LunarLunar SectionSectionCirCircularcular

Vol. 49 No. 5 May 2012

Director: Bill Leatherbarrow Editor: Peter Grego

From the Director

At this time of year the young crescent Moon rides high in the evening sky, but as the lunation progresses our

satellite falls ever lower as seen from the UK. This is a reminder of the summer months to come, when lunar

observation is marred not only by the limited hours of darkness, but also by the poor seeing that inevitably

accompanies the Moon’s low altitude. This makes high-resolution observation very difficult, and many

observers put away their telescopes until the autumn. However, there is one project that will repay continued

observation even when the Moon between first and last quarter is firmly ensconced south of the celestial

equator.

Tycho’s ray system, from an image by Maurice Collins on 2008 October 13 using a C8 and LPI.

Image rectified in LTVT, autostitched and processed in Photoshop.

BAA Lunar Section Circular Vol. 49 No. 5 May 20122

Bright rays and ray craters have been familiar features of the Moon near full since the invention of the

telescope, yet surprisingly little systematic attention has been paid to them. Of course we know that the ray

systems consist of ejecta from relatively fresh impact craters, such as Tycho, Kepler and Copernicus. But we

know little else. We know that unequal distribution of ray material around the source crater is a likely indicator

of an oblique impact, but there have been few systematic attempts to chart such examples. We know the location

of the major ray systems, but little effort has been made to study in detail the distribution, lengths and patterns

of the rays. Some of the rays from Tycho appear to be tangential to the crater rim, rather than radiating from the

centre—is this the case elsewhere and, if so, what might it tell us about how rays originated? Are the lengths of

rays proportional to the size of the crater from which they originate? Are rays interrupted along their lengths by

other topographical features and, if so, how? Such questions are yet to be fully addressed.

In a recent LPOD Chuck Wood called upon amateurs to make ray maps for all the major ray craters (LPOD,

March 26, 2012). Previous attempts to do this have been patchy. In the 1960s Robert J. Hackman of the US

Geological Survey team produced an outline map of the major ray systems; the full map is featured online at

http://www.lpi.usra.edu/resources/mapcatalog/ESS/I351B/72dpi.jpg And in the age before space probes

observers such as H.P. Wilkins and E.F Emley traced the patterns of rays in the limb areas in order to try to infer

the existence of ray craters on the Moon’s hidden hemisphere. A portion of Emley’s chart is reproduced above.

These are examples of the sort of systematic approach to rays that we now need to follow up in more detail,

and it is the kind of observational work that can be done at lower resolution even when the Moon is low. It offers

possibilities to both the visual observer and the imager, and I hope that you will consider attempting it in the

months ahead.

Bill Leatherbarrow

Director, BAA Lunar Section

Detail from Emley’s chart showing ray systems near the Moon’s northern limb.

Detail from Hackman’s chart showing ray systems near the Moon’s northern limb.

BAA Lunar Section Circular Vol. 49 No. 5 May 2012 3

Topographical notes compiled by Peter Grego

Visual studies and observations

Since April’s LSC, visual topographic lunar observations have been received (or linked to) from Peter Grego

(St Dennis, UK), Chuck Hastorf (Arizona, USA), Philip Jennings (York, UK), Chris Lee (Bristol), Phil

Morgan (Tenbury Wells, UK) and Michael Roe (UK). Some of these observations are reproduced below.

A note on submitting visual observations

All visual observations should, in the first instance, be sent to the Director, Bill Leatherbarrow, by regular

mail or, as is far more frequently the case these days, as email image attachments (Bill’s address is on the last

page). If possible, please copy me in on the email with the attachments at [email protected], as

it saves Bill the need to send them on to me for consideration for inclusion in the LSC.

Please note that while observations are encouraged to be posted to the Lunar Section Visual Studies

Yahoo! Groups website http://uk.groups.yahoo.com/group/baalunarsection-topography/ it’s important not to

regard this as the official Lunar Section archive or the primary repository for observations. The site is meant

to be an adjunct to the main work of the Lunar Section, and serves as a forum, so please ensure that if you do

post observations there, also to send them to the Director (and me if possible). That way, nobody’s work will

be missed and it will be officially archived, available for comment and analysis.

Clarity in labelling image and observation files is important, both to avoid ambiguity and confusion and

to make filing, archiving and accessing material easier and more efficient. Ideally, all image files should

contain unambiguous date and time data, feature observed, instrument used and observer name. Other

information pertaining to the observation, such as colongitude and libration, should be included in the

covering notes, along with a written description (if any) of the observation.

Eratosthenes

Observation by

John Meacham

2012 February 1

20:30-21:00 UT

Sun’s col. 29.3°

Seeing: AII

125mm MCT, 160x

Notes: Several bright spots

at central mountain suggest

high peaks.

Menelaus

Observation by Peter Grego

(St Dennis, Cornwall, UK)

2012 March 28

1: 19:45-20:00 UT

2: 20:25-20:38 UT

3: 21:10-21:22 UT

4: 21:40-21:51 UT

Col. 1: 342.6-342.7°

Col. 2: 342.9-343.1°

Col. 3: 343.3-343.4°

Col. 4: 343.6-343.7°

Seeing: AII, clear, no wind.

100mm refractor, 132x

Integrated light

Original observational PDA sketch

made freehand (no template used)

Notes: Sunrise over Menelaus.

The sequence was sketched on

PDA, the first sketch being made

freehand without a template. The

observations presented here are

the original PDA sketches; the

only post-observation

enhancement has been to increase

the dpi, remove moiré and include

the relevant text information. At

the beginning of the observation it

was decided to take in the

shadowed area (most of the area

covered by the observational

drawing) west of Menelaus in


Eratosthenes

Observation by

John Meacham

2012 February 14

04:45-05:15 UT

Sun’s col. 170.5°

Seeing: AIII. Poor, some haze

125mm MCT, 160x

Notes: The observation was

made near last quarter. The west

ends of the Apennine mountains

were in dark shadow, with a few

high peaks in sunlight. The

south rim of the crater appeared

as a gap from the floor out into

the Sinus Aestuum and beyond.

The central mountain peaks

were prominent.

1 2

3 4


order to observe and record any high topographical points which might later become illuminated by the rising

Sun. A watch was kept in order to determine when any features on Menelaus’ floor might first become visible.

When the observation was commenced, Menelaus was firmly in shadow; only a sliver of its inner western

wall and a broader crescent of its outer eastern flanks were illuminated by the rising Sun. Initially, the

brightest feature visible was the southern part of Menelaus’ eastern glacis; the inner western wall appeared

far dimmer. However, by the time that the second sketch was made the northern part of the inner western wall

had increased to what appeared a similar brightness to Menelaus’ eastern flanks, and part of the southern rim

had begun to make an appearance. It was obvious, by the time the last observation was made, that the once

bright part of the crater’s eastern flanks had grown dimmer in comparison with the bright portion of the inner

western wall. The last observation also saw the appearance of a small detached point of illumination within

the shadow of Menelaus’ interior, not very bright, in the west quite close to the illuminated inner wall. The

feature was quite obvious and unambiguous, and it was assumed that this must have been one of the crater’s

interior hills. However, on consulting Rükl’s map 23 while writing up these notes is there is no really obvious

elevated point in the vicinity of this feature, but it may possibly have been part of the lower inner wall

catching sunlight. The northwestern rim failed to appear. A number of other features around Menelaus, both

within Mare Serenitatis and along the Montes Haemus, became visible during the session. Notable among

them was unnamed dome north of Menelaus (connected to northern Menelaus by a low ridge), extensions to

the hills and ridges of Montes Haemus near Sulpicius Gallus B (the crater itself was not clearly seen) and

ridges around Lacus Hiemalis.

Arago with domes

Observation by

Philip Jennings

2012 March 28

19:14-20:30 UT

Sun’s col. 342.9°

Seeing: AIII

200mm SCT, 226-339x


Notes: A particularly fine view of the Spitzbergen range at sunrise was enjoyed. Situated some 65 kilometres

to the north of the outer northern glacis of Archimedes, the entire range is some 60 kilometres in length, and

is probably the remains of a once fine inner Imbrium mountain ring. Despite the fact that none of the

individual peaks attain a height of over 1,500 metres, at both sunrise and sunset some of these cast very fine

spires of shade, and on this occasion they were seen spreading some 65 kilometres (about 40 miles) to the

west of the range. Just immediately to the west of the Montes Spitzbergen is a fine broad flat-topped wrinkle

ridge which gently meanders down to the 12 kilometre crater Kirch, and then continues on its northern

journey almost as far as the Mons Pico.


A new lunar resource: The Photographic Lunar Album by K.C. Pau Rafaello Lena

I am very impressed with new available photographic lunar album by K.C. Pau, a valuable resource for lunar

observations. K.C. Pau produced 109 plates reporting his telescopic images of high quality. This remarkable

album provides a compilation of relevant images accessible for the amateur interested in observing the Moon

in order to have a solid base for lunar studies. In fact, some of the lunar regions are shown under different

solar angles allowing the study of many elusive structures, such as elusive rilles and domes.

The best thing about this album is the demonstration how amateurs can go about pursuing this type of

observing activity, exactly what that Pau does on a regular basis since decades. Digital imaging enhanced

amateur capabilities demonstrating the utility of CCD-image analysis in the elucidation of lunar domes and

their properties, providing important geologic information and measurements for their classification. Many

of these excellent images made by Pau have been analyzed allowing the publication of several GLR articles

in professional journals.

I was lucky to meet, some years ago, K.C. Pau in Rome talking with him about the projects concerning

lunar researches, and the valuable resource represented by a new lunar atlas. Our past activities, made in the

GLR group, are really memorable and very meaningful, stimulating further studies and observations of many

elusive features, most of them proposed by Pau. As examples I can mention the rille traversing the large

Valentine dome, the smaller northern dome, the elusive rilles near Manilius and Lassel, features identified

before of the high resolution imagery recently taken by probes such as Selene and the LRO!

I am glad that K.C. Pau, active amateur astronomer in GLR group, has produced this remarkable resource

with enough variety of lunar regions to interest any lunar enthusiast. Surely it is the first important result of

a series of upcoming books born, likely, during the productive activities developed in the GLR group with

combined efforts in order to understand the geologic processes occurred in our Moon. I am sure that this

unique principle will allow the publication of further books.

Moreover, as the new photographic lunar album by Pau shows, elusive objects must be imaged under very

oblique solar angle, demonstrating how exploring the terminator can still be productive for lunar

investigations based on telescopic CCD images. The results of the work done by Pau, as the work done by

the GLR group, demonstrate that our moon is a resource to be still explored.

The price of the album is as follows: UK: 10

GBP + 6 GBP airmail. EU: 12.00 Euro + 7.5 Euro

airmail/ US: $16 + $9.5 airmail. Anyone interested

in this valuable lunar resource can email to K.C. Pau

[email protected]

Let me conclude, referring to my compatriot

Gaetano Filangieri (1784), that “saying that

everything has already been done is the language of

those who either lack ability or courage.”. This

principle, illustrated in the images presented in this

recommended valuable album should be the

inspiring base and the key for the youngest

generation of amateur astronomers.

Raffaello Lena

GLR group founder, editor in chief of

Selenology Today

http://digilander.libero.it/glrgroup/

Bill Leatherbarrow writes: K.C. Pau has kindly

donated a complimentary copy of his album to the

BAA Lunar Section, and I have written back to him

expressing our thanks. It is, as Raffaello says, a fine

piece of work (especially taking into account the

conditions under which KC works in central Hong

Kong).

7


Join us at our Yahoo! Group: Lunar Topographic Studies

http://uk.groups.yahoo.com/group/baalunarsection-topography/

More lunar observational drawings, including

observations featured in previous Circulars, can be

found on our Yahoo! Group. Membership of the

group is open to both BAA members and non-

members, and group members can also post their

own notes and lunar observations on the site.


A note on Ptolemaeus Nigel Longshaw

Firstly I would like to thank the Director for his kind words in the last circular relating to my examination of

the ‘ashen light’ in Plato which was published in the March Lunar Section Circular. As the director rightly

points out its important not to look too narrowly at the selenographic record, and in particular anomalous

observations from the past, as certain appearances can often be repeated under the most unexpected

circumstances. Despite our knowledge of the lunar surface, the Moon’s movements and lighting conditions,

apparently pinned down by computer programs and mathematical calculations, the Moon can still surprise

even the most seasoned observer.

It is clear from communication I had with Gerald North, incorporated in my additional note on Plato in

the last Circular, that even though after consulting the relevant data we might think we know what to expect

when we go to the eyepiece, however the lunar surface often throws up anomalies which were not expected.

In this regard it was with interest that I read Tony Cook’s description of an observation of Ptolemaeus in

the last Circular (page 19 note 4). Initially the language used to describe the observation intrigued me. On

1970 April 14 the Brazilian astronomer described ‘a kind of glimmering mist lifted and wafted inside the

shady hollow of the crater’ under sunset conditions. The ‘repeat lighting’ image by Brendan Shaw shows

Ptolemaeus completely shadow filled yet the computer modelling carried out by Tony indicates grazing

illumination on the crater floor. As Tony rightly says this effect is very reminiscent of those seen in Plato

under sunrise and sunset conditions. It is at such times that Phil Morgan and I noted the appearance of an

‘ashen light’ on the floor of Plato.

Is it possible that a similar lighting

effect manifests itself in

Ptolemaeus at sunset and was seen

by the Brazilian astronomer?

The language of description is

similar ‘glimmering mist’, milky

light’ and so forth. The Brazilian

astronomer’s description of

apparent movement of this

ephemeral light could be

explained by seeing conditions as

Tony suggests, whatever the

explanation it’s clear that

something at the very edge of the

astronomer’s vision and

interpretation was seen in 1970.

Is it possible that under

extreme conditions of sunrise or

sunset over certain lunar features,

maybe those larger craters with a

large relatively smooth inner

surface, surrounded by a relatively

regular rim, we see the last

vestiges of a dim sunlight glow on

the crater’s interior at sunset?

Alternatively under sunrise conditions might we also be able to detect the first effects of sunlight bathing the

crater surface before the early shafts of sunlight stream through valleys in the crater wall and focus our

attention with their brilliance. In both cases perhaps under those extreme angles of illumination, without the

intensity of ‘direct’ sunlight the boundaries between light and shadow become too diffuse to be resolved by

eye and telescope?

As Bill indicated, it would certainly be worthwhile keeping a close eye on Plato, and perhaps we now

might include Ptolemaeus, under extreme conditions of sunrise and sunset in order to see if the phenomenon

is repeated without relying too heavily on what we might expect to see from consultation of the ephemeris.

LRO image of Ptolemaeus. NASA.


Observations of the lunar south polar area Michael Roe

These four sketches were made of the southern cusp in March and April 2011 using a 200mm SCT, 220x, and

they are presented in order of advancing colongitude. The area varies a great deal as libration and lighting

angle change. Only a few fragments remain above the blanket of shadow at these colongitudes, making

identification of features very difficult in this mountainous region.

2011 March 6 18:20 UT Col. 292.2° Libration lat. -6.5° Libration long. -1.4°

Amundsen Leibnitz B

and M6? M5

2011 March 7 19:00 UT Col. 304.7° Libration lat. -6.2 Libration long. -2.7

R6 Amundsen Liebnitz B South pole Mountains

south of

Cabaeus M5

2011 March 8 18:25 UT Col. 316.5° Libration lat. -5.6° Libration long. -3.9°

M6? South pole Mountains

Liebnitz B below south of Cabaeus M5

2011 April 7 20:05 UT Col. 322.9° Libration lat. -2.5° Libration long. -5.9°

Boguslawsky Demonax Scott Leibnitz B South pole M5

north wall


On the related seeing deformation affecting the gamma peak shadow:

a simultaneous and independent survey Rafaello Lena

Two papers appeared in the

Journal of Lunar & Planetary

Observers proposed that the hook-

like shadow on the floor of the

lunar crater Plato drawn by

Wilkins and Moore on 1952 April

3 (Figure 1, shown at right) is

projected by a complex and

elongated hill lying on Plato’s

floor (Favero, Lena, et al, 2000;

Favero, Lena, et al, 2001). To

explain these differences some of

us have suggested that the English

observers each executed at the

telescope only a partial drawing

intended only to record a few

features on Plato’s floor, including

the hook-like shadow. In another

paper published in JALPO (Lena

et al, 2002) we have carried out a

survey with simultaneous and

independent observations on dates

proposed by other observers where

the hook should be detectable (cf. Lena et al, 2002 and references therein). During the mentioned survey we

have demonstrated that any curvature detectable in our images lasts only small intervals of time and is related

to seeing-induced deformations. Because of these fluctuations, and no simultaneous and independent

confirmation, curvature in any of the images (displaying a hook) must be considered to be spurious.

A new observing session was recently proposed in order to have a confirmation of the Plato hook, which

was attributable to the Gamma peak shadow. See http://luna.uai.it/index.php/Ombra_nel_cratere_Plato

To study the possible causes of the aspect of the Gamma Peak’s shadow, several observations were carried

out. In this work I present the result of two images taken exactly at the same time, on 2012 March 1 at 20:33

UT, with two independent observations and from two observatories located about 200 km apart. Instrument,

data and the two images (by the author of this article and Andrea Tomacelli) are reported in Figure 2 (shown

overleaf). Results confirm that any curvature detectable is related to seeing-induced defocusing and

deformations, confirming the previously conclusion published in JALPO (cf. Lena et al, 2002). Moreover

images with crisper detail show a straighter shadow. This has broad implications for amateur astronomers in

an age when imaging is considered to yield definitive data.

Raffaello Lena

GLR group founder, editor in chief of Selenology Today

http://digilander.libero.it/glrgroup/

References:

Lena R., Di Iorio G., Bares A., Fattinnanzi C., Favero G. (2002) Plato's Hook, Part III: On the Curvature of

the Gamma Peak’s Shadow on Plato's Floor, JALPO, vol 44 (4), pp.37-43.

Favero G., Lena R., Lottero F., Fiaschi M. (2001) The nature of the hook-like shadow on Plato's floor

observed by Wilkins and Moore in 1952—Part II. Simulations with a computer and a plasticine model.

JALPO, 43(3), pp. 24-29.

Favero G., Lena R., Mengoli G., Cipolat A., Gualdoni P. (2000) The nature of the hook-like shadow observed

by Wilkins and Moore on Plato's floor in 1952. JALPO, 42(3), pp. 126-132.

Figure 1.


Figure 2.


Reinhold and Lansberg by Chris Lee.


Images

Since April’s LSC, lunar imges (or links to images) have been received from Maurice Collins (New Zealand),

Ed Crandall (USA), David Finnigan (UK), Kevin Kilburn (UK), Richard Hill (USA) and David Scanlan

(UK). A selection of these images is featured below. My apologies to those contributors whose hard-won work

is not featured in this issue; as usual space considerations mean that only a representative sample of material

is included. Images intended as part of the Section’s ongoing investigations into lunar colours should be

sent to [email protected] who will pass them on to Kevin Kilburn. Occasional updates on

lunar colour observations will appear in future issues of the LSC.



Ed Crandall’s images of the Moon, taken on 2011 December 1 using a 110 mm f6.5 apo, 3x Barlow

and Toucam. The image above shows Aristoteles and Eudoxus (23:14 UT), the image below shows

Atlas and Hercules (23:16 UT).


Transient lunar phenomena, May 2012 Tony Cook

Routine observations for March 2012 were received from the following observers: Jay Albert (Lake Worth,

FL, USA) observed: Alpetragius, Alphonsus, Aristarchus, Biot, Briggs, Censorinus, Cleostratus,

Eratosthenes, Plato, Posidonius, Pythagoras, the South Pole, Schickard, Torricelli B and Tycho. Rolf Carstons

(New Zealand) took a whole disk image of the Moon. Maurice Collins (New Zealand) took an image of

Copernicus and whole disk images of the Moon. Marie Cook (Mundesley, UK) observed: Alphonsus,

Aristarchus, Bullialdus, Censorinus, Copernicus, Eratosthenes, Hercules, Kunowsky, Messier, Mons Pico,

Pico B, Plato, Posidonius, Proclus, Tycho, and Yerkes. I took time lapse video of the Moon and also videod

Earthshine, looking for impact flashes from Aberystwyth University (to gain additional footage for my

undergraduates). Peter Grego (St Dennis, UK) observed Menelaus. Rolf Hempel (Germany) took a whole

disk image of the Moon. Norman Izett (New Zealand) took whole disk images of the Moon. Jim McAloon

(New Zealand) observed Aristarchus, and Mare Humorum. Pietre Malinski (Poland) imaged several areas of

the Moon. Bob O’Connell (Keystone Heights, FL, USA) observed Alphonsus, Aristarchus, Briggs, Manilius,

Menelaus, South Pole, and Schickard. Peter Odin (Germany) took a whole disk image of the Moon. Brendan

Shaw (UK) imaged Aristarchus, Eratosthenes, Plato, Mare Crisium, Torricelli B, Tycho, and several other

features.

News: It was interesting to read Nigel Longshaw’s article in the March BAA Lunar Section Circular on a

sunrise and sunset appearances of the floor of Plato, and how these may explain some TLP reports about this

crater from the past. I will certainly be updating the weights of many of the past Plato TLP reports in due

course, and probably even taking some out of the TLP category. But for now, please keep on observing at the

times given in the predictions web site, because even if some of the original reports are not TLP, by all

accounts they are still spectacular to observe and anyway make useful additions to the routine observations

database that I am using to calibrate the TLP database with.

Routine Reports: As usual, space is rather limited to describe all of the routine reports sent in, but here are

just a few highlights from March 2012:

Figure 1 (Left) Maurice Collins’ image from 2008 Jul 7 showing a tiny but very bright dot on the northern

shore of Mare Crisium – north is towards the top right. (Right) Brendan Shaw’s image from 2012 Mar 27

UT 18:51 with a similar very bright white spot near the top of the image.

1) Mare Crisium: On 2008 Jul 07 UT 05:28-08:36 Maurice Collins imaged a very bright spot on the northern

shore line of Mare Crisium. As you can see from Figure 1 (above, left) this was appreciably brighter than

other features in the area. We gave this observational report a TLP weighting of 1 originally, because although

a ray crater can be found near the top end of a (45º according to LRO) slope at this location in the

Consolidated Lunar Atlas, the Kaguya Lunar atlas, and also in Apollo and LRO images, it did seem somewhat

brighter than what one might expect from this ray crater alone. I was therefore very interested to see an image

by Brendan Shaw, from about a day later in colongitude that showed a similarly very bright spot here. Now

that we have this, and it matches the brilliance, I am happy to eliminate this from the TLP list, even though

it is not exactly similar illumination. I am also removing Don Spain’s report on a bright spot from 2005 Jan

15 (a daylight observation) from the TLP list, and a couple of reports by Peter Andersen from 1980 Mar 20

and Apr 21. Malcolm Ellis wrote in a letter to the BAA Lunar Section Circular (1980, p65) that this spot is at

its brightest between colongitudes of 310º-350º, with it peaking in brightness at 320º. He also commented that


it is the brightest spot on the Moon

up until nearly first quarter. So

although not regarded as a TLP

site any longer, observers might

want to keep an eye open for this

feature to test out the claims that it

can appear to be one of the

brightest points on the Moon, for a

certain set of phases. I guess that

doing a brightness threshold on

digital images would be a good

test to see how it ranks with

Proclus and Censorinus in terms

of brilliance.

Figure 2. Prinz by Piotr Malinksi

taken on 2012 Mar 04 at UT

19:30 with north at the top.

2) Prinz: On 1975 Feb 22 UT

19:00-22:50 Peter Foley, using a

30cm reflector (seeing good)

observed Prinz to have a diffuse

white obscuration with pulsations

of 30-50 sec intervals. The effect

faded and had ceased by 22:50. Photographs were taken but showed nothing unusual, and no colour was seen.

On 2012 Mar 04 UT Piotr Malinksi took some high resolution images of the Moon; one of them covered Prinz

crater and can be seen in Figure 2 (above). This clearly shows no sign of anything that might have resembled

an obscuration. Therefore the weight for the Foley TLP observation will remain at 2; not quite making it to a

3 because the photographs taken at the time did not reveal anything, but of course old fashioned photographic

resolution was always worse than visual resolution.

3) Kunowsky: On 1964 Sep 22 UT 03:25-04:30 Gilheany, Hall and Johnson (Port Tobacco, MD, USA,),

using a 40 cm reflector, under good seeing conditions, detected a red area in this 18 km diameter crater (SW

of Copernicus), using a Trident electronic Moon Blink device. Marie Cook checked out the crater under the

same illumination conditions on 2012 Mar 8 UT 22:05-22:15, and found that the crater looked brighter in a

red filter too, although she was using a smaller 90mm Questar telescope (seeing Antoniadi III, transparency

moderate to poor). I have checked the Clementine UVVIS Multispectral Mosaic on Map-a-Planet Explorer

(http://www.mapaplanet.org ) but cannot find a natural reddish colour to this crater, so maybe it is an effect

specific to this phase angle? Kunowsky would certainly be in interesting challenge for colour imaging

enthusiasts within the Lunar Section!

4) Briggs. On 2010 Apr 27 UT 00:10-00:30 and 01:45-02:00 Peter Grego (20 and 30 cm reflectors) sketched

Briggs and found a craterlet to the east that did not appear on the NASA LAC chart of this area, and there

was also an E-W curvilinear marking coming off this crater to the east (see Figure 3 overleaf). Brendan Shaw

in March 2011 re-imaged the area and confirmed the craterlet did exist, but that there was no sign of the E-

W marking. Jay Albert and Bob O’Connell re-observed visually under similar illumination conditions on

2012 Mar 06. Jay used a 28 cm SCT with transparency at 4th magnitude and seeing varying from (4-6)/10.

Jay observed from 03:50-04:20 UT at 311x and reported: “The tiny craterlet close to and E of Briggs was

easy to see, even when the seeing deteriorated to 4/10. This tiny craterlet is E of the N-S wrinkle ridge

bordering Briggs to the E and N of the two larger craterlets SE of Briggs. The latter two craterlets are shown

on chart 17 of Rukl, but the tiny craterlet is not. I could not detect an “E-W trending lineament or wrinkle


ridge”. I could plainly see the ejecta ray running NE from Seleucus, but no wrinkle ridge. There were a

couple of low hills lined up to the E of the tiny craterlet, but they weren’t connected and didn’t form a ridge.

Briggs itself was just beyond the terminator with only its exterior E wall rising out of the shadow. Bob

observed at 04:20-04:26 UT in white light using a 23 cm SCT, with a 160x binoviewer (seeing 3/10). He saw

the eastern rim of Briggs on the terminator and detected the craterlet just to the east of Briggs, but like Jay,

did not see the E-W trending lineament. Bob captured an image earlier at 03:29UT and this can be seen in

Figure 4, again no sign of the E-W lineament. So the issue concerning Peter Grego’s original observation is

not the craterlet failing to be present on maps (it does appear on Lunar Orbiter imagery from the 1960s), but

why does the E-W lineament not show again? I am raising the weight of this TLP report from a 1 to a 2. Let’s

keep on looking, trying to get higher resolution imagery at sunrise over this area to see if we can fathom out

what was seen?

Figure 3. Peter Grego’s PDA sketch of Briggs (rectified to match the LAC chart at right) from 2010 Apr 27

with north at the top.

Figure 4. (Left) Bob O’Connell’s image of Briggs from 2012 Mar 06. (Right) Same image but after

undergoing high pass filtering (radius 9 pixels) to remove large scale brightness trends. The dark shading

either side of Briggs is an artefact of image enhancement. North is towards the top.

TLP Reports: One TLP report was received during March. On 2012 Mar 28 Peter Grego was making some

PDA sketches of Menelaus at sunrise using a 10 cm refractor at x132 (Seeing Antoniadi II). All seemed to be

a normal sequence in the four sketches made at: 19:45-20:00, 20:25-20:38, 21:10-21:22, and 21:40-21:51 UT,

except that upon checking up later on the last sketch (Figure 5e), Peter noticed an illuminated patch just inside


the western rim, that does not show up in the previous sketch (Figure 5d) or on other images taken earlier that

night of sunrise over the crater (Figure 5a-c). Bill Leatherbarrow found an image from a higher sun angle that

shows something closer to the floor (Figure 5h), however computer simulations with ALVIS do not replicate

the illuminated patch at the time of Peter’s sketch (Figure 5f), or even allowing illumination from over the

entire half a degree angular diameter of the solar disk (Figure 5g). A check on NASA’s LRO LOLA

topographic dataset sSee Figure 6) shows no obvious terrace on the inner crater wall. So therefore I am

therefore assigning a weight of 3 to this report for now, until we obtain some imagery closer to the same

illumination and can determine if perhaps the illuminated spot is due to something like scattered light from

the lit part of the crater lighting up some bright albedo marking in the shadow?

Figure 5. The above images, sketches and simulations all have north towards the top and are from 2012

Mar 28 unless specified otherwise. (a) Image by Brendan Shaw from 17:55 UT (Col.=341.8º). (b) Image by

Rolf Hempel from 18:59 UT (Col=342.3º). (c) Image by Peter Odin from 19:37 UT (Col.=342.6º) (d) PDA

sketch by Peter Grego from 21:10-21:22 UT (Col.=343.5º). (e) PDA sketch by Peter Grego from 21:40-

21:51 UT (Col.=343.7º). (f) ALVIS simulation for 21:46 UT (Col.=343.7º). (g) ALVIS simulation for 22:46

UT (Col.=344.2º) or 0.5º later to take into account the angular diameter of the solar disk. (h) Image by Bill

Leatherbarrow from 2009 Apr 01 UT 18:58 (Col.=350.0).

Figure 6. Topographic cross-sectional profile through Menelaus from East to West using ACT-REACT

QuickMap available on the LROC web site: http://target.lroc.asu.edu/da/qmap.html


Suggested Features to observe in May: For those of you without access to the internet (in the UK), below

is a list of repeat conditions for when a feature will exhibit the same illumination and libration as was seen

for a historical TLP observation from the past. By re-observing and submitting your observations, we will get

a clear understanding of what the feature ought to have looked like at the time. Only this way can we really

fully analyze past TLP reports.

2012-May-01 UT 19:29-19:50 Ill=75% Hevelius observed by Emmett on 1826-04-17: Please image or

sketch.

2012-May-02 UT 19:31-20:39 Ill=85% Torricelli B observed by North on 1995-04-11: Can you see or

image any colour on the crater and how bright or dull is the crater?

2012-May-02/03 UT 21:05-00:51 Ill=85% Promontorium Laplace observed by Beraud on 1970-08-13:

Almost certainly jest a shadow off the very steep peak, but please verify.

2012-May-03 UT 19:32-20:40 Ill=93% Aristarchus observed by Foley on 1975-02-23: Any colour seen and

does this change over time?

2012-May-14 UT 02:08-04:19 Ill=38% Aristarchus observed by Sekiyuchi 1970-07-26: Please image or

sketch.

2012-May-16 UT 02:44-03:08 Ill=20% Elger observed by Merosi on 1970-08-27: Can you see this in

Earthshine and does the crater change in brightness as the seeing or transparency varies?

2012-May-26 UT 21:00-21:30 Ill=30% Please check Earthshine for sporadic meteor impact flashes.

2012-May-27 UT 21:02-21:54 Ill=40% Please check Earthshine for sporadic meteor impact flashes.

2012-May-30 UT 20:12-23:24 Ill=72% Archimedes observed by Miranda on 1971-08-01: Can you see two

grooves or rays going from east to west, broadening towards the west?

For repeat illumination (only) TLP predictions for the coming month, these can be found on the following

web site: http://users.aber.ac.uk/atc/tlp/tlp.htm .For members who do not have access to the internet, please

drop me a line and I will post predictions to you. If you would like to join the TLP telephone alert team, please

let me know your phone No. and how late you wish to be contacted. If in the unlikely event you see a TLP,

please give me a call on my cell phone: +44 (0)798 505 5681 and I will alert other observers. Note when

telephoning from outside the UK you must not use the (0). When phoning from within the UK please do not

use the +44! Twitter TLP alerts can be accessed on http://twitter.com/lunarnaut.

Dr Anthony Cook, Institute of Mathematical and Physical Sciences, University of Wales Aberystwyth,

Penglais, Aberystwyth, Ceredigion, SY23 3BZ, Wales, United Kingdom.

Email: atc @ aber.ac.uk.


Occultation news, May 2012 Tim Haymes

Graze occultations. R. Emery (Leeds) requested track information for the Zeta Tauri graze on April 25

(BAAH 2012, entry 6).This was expected to be best graze event of 2012. Jupiter will graze the Moon on July

15, 02h. Jean Meeus provided data on the track and satellite phenomena in February’s BAA Journal, page 31.

There is a pdf in the public domain here: http://www.shindles.co.uk/ouastro/jup-occult-meeus.pdf

Double star video. This project aims to detect new doubles, or confirm existing doubles using video

techniques. Observations are needed to increase the success rate. The details of the analysis are bit tricky, but

the important aspect is to record lunar occultations by video and report them to the co-ordinator who can do

some preliminary analysis. The data is then sent to IOTA for comparison with other observers results of the

same star at a diffent lunar position angle. If you have access to one of the many video cameras now available

(Mintron, Watec etc) then you can contribute. I have details of the observation techniques involved. Contact

me for a copy.

Occultations are listed here for Birmingham. Observers elsewhere will need to adjust the prediction by several

minutes. I can produce predictions for any location. Contact me if you would like a set.

Occultations Co-ordinator: Tim Haymes, Hill Rise, Knowl Hill Common, Reading, RG10 9YD.

[email protected]

Cloud Watch observations for March 2012 Andrew Bytnar

Observer and location Excellent Cloudy Overcast Hazy No watch

days days days days days

P.Burt (Chatham) 16 (52%) 1 (3%) 11 (35%) 2 (6%) 1 (3%)

A.Bytnar (Mansfield) 13 (42%) 1 (3%) 16 (52%) 1 (3%) -----

M.Cook (Cromer) 1 (3%) 14 (45%) 12 (39%) 4 (13%) -----

K.Hall (Warrington) 9½ (31%) 7 (23%) 12½ (40%) 2 (6%) -----

A.Heath (Nottingham) 14 (45%) 8 (26%) 8 (26%) 1 (3%) -----

J.Wrigley (Reading) 7 (23%) 10 (32%) 11 (35%) 3 (10%) -----

Cloud Watch observations to: Andrew Bytnar, 20 Mansfield Road, Sutton-in-Ashfield, NG17 4EJ.

[email protected]


Lunar librations for May 2012 (from a program by J.M.H. Hill)


To receive B&W printed copies of the Lunar Section

Circular, please send a supply of stamped addressed

envelopes to the Lunar Section Director. Envelopes at

least 11 x 22 cm will ensure no damage in transit.

Members who have Internet access may receive their

Circulars (colour version) in PDF format by email

(please contact the Director) or by downloading them

directly from the BAA Lunar Section website at

http://www.baalunarsection.org.uk/circulars.htm.

BAA Lunar Section Director: Bill Leatherbarrow,

9 Stumperlowe Avenue, Sheffield, S10 3QN, UK.

Email: [email protected]

Observations and items related to a specific area of

lunar study should be sent to the appropriate member

of the BAA Lunar Section Committee, but send any

material of a more general nature to the Editor.

Deadline for items for the June 2012

Lunar Section Circular:

15 May 2012

Circulars Editor: Peter Grego, 7 Parc-An-Bre Drive,

St Dennis, St Austell, Cornwall, PL26 8AS, UK.

Email: [email protected]

BAA Lunar Section Contacts

Director

Bill Leatherbarrow

[email protected]

Assistant Directors

Tony Cook (with responsibility for TLP work)

[email protected]

Peter Grego (Circulars Editor)

[email protected]

Committee Members

Tim Haymes (Occultations)

[email protected]

Robert Garfinkle (Historical Consultant)

[email protected]

Bruce Kingsley (Imaging Consultant)

[email protected]

Nigel Longshaw

Brendan Shaw (Archivist)

[email protected]

Computing Consultant (position vacant)

[email protected]

Lunar data for May 2012, lunations 1105/1106 (from a program by Gareth Williams)

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