CMO Mars September 2003

^th Report:

The CMO/OAA Observations made during a fortnight period from

1 September 2003 (252°Ls) to 15 September 2003 (261°Ls)

An OAA Mars Section article to be published in CMO #279 (25 September 2003 issue)

Masatsugu MINAMI, Director of the OAA Mars Section

HE planet Mars being just after opposition, the biggest angular diameter δ has begun to decrease. However even on 15 September, δ read 23.6", and not so different from the maximal diameter = 23.8" in 1988. On 13 September, TSUNEMACHI (Ts) was still able to detect the tiny Juventæ Fons and the light Aurea Cherso clearly by the use of a 12.5cm refractor (based upon her experiences in August at Naha). And so it was rather strange enough to see that several observers tended to withdraw their eyes from the still attractive planet. Visual observers like MURAKAMI (Mk) and IWASAKI (Iw) augmented their observation rates in September. The season proceeded from λ=252°Ls to 260°Ls during the period: the former corresponded to the season when the 1956 encircling dust storm was onset, and the latter pointed to the very season of the entraining of the 1971b great dust storm. The central latitude φ remained 19°S, and the phase angle ι increased from 6° to 15°. The apparent declination of Mars went down to - 16.5° on 15 September, but this was the extreme, and was to rise gradually up henceforward.

HE observers have begun decreased in number as suggested and a total is less than sixty. As September came in, the weather in Japan quite recovered and the observation rate increased. However in Europe, the situation looked different: If it was because of the weather condition, the zigzagged westerly zone at the middle latitudes must have brought constantly an opposite configuration to Japan from Europe during the 2003 summer.

AKUTSU, Tomio (Ak) Tochigi, Japan

33 Sets of CCD Images (2, 4, 5, 9, 11, ~15 September 2003)

f/33×32cm spec with a Bitran BJ-41L

ASADA, Tadashi (As) Munakata, Fukuoka, Japan

50 CCD Images (18, ~23, 27 September 2003)

30cm SCT with a Panasonic NV-MX5000

BATES, Donald R (DBt) Houston, TX, USA

3 CCD Images (1, 6, 7 September 2003)

f/24,32×25cm spec with a ToUcam Pro

BEISH, Jeffrey D (JBs) Lake Placid, FL, USA

1 Drawing (8 September 2003)

390, 590×41cm F/6.9 speculum

BENAVIDES, Rafael (RBn) Córdova, España

16 CCD Images (1, 2, 3, 10, 14, 15 September 2003)

24cm SCT with a ToUcam

BERRY, Peter (PBr) Panama City, FL, USA

2 CCD Images (3 September 2003) f/30×23cm SCT with a TRV-900

BUDA, Stefan (SBd) Melbourne, Australia

4 CCD Images (1, 6, 12 September 2003)

f/48×25cm Dall-Kirkhams with an evolved TC211

BUNGE, Robert (RBg) Bowie, MD, USA

2 Drawings (6, 7 September 2003) 480×43cm F/7.8 spec

CHAVEZ, Rolando (RCv) Powder Springs, GA, USA

3 CCD Images (1, 9, 13 September 2003)

20cm F/7 spec with a ToUcam

CRUSSAIRE, Daniel (DCr) Champigny-sur-Marne, France

2 Sets of CCD Images (3*, 8 September 2003)

10cm Fluorite L with a Vesta Pro

*25cm Cass (named Caroline) with a Vesta Pro at Meudon

DENNERL, Konrad (KDn) 　München, Deutchland

1 CCD Image (4 September 2003) 11cm spec with a ToUcam Pro

DIJON, Jean (JDj) 　Sillans, Isêre, France

1 CCD Images (3 September 2003)

57cm spec (down to 20cm) with a KAF400 chip camera

DOBBINS, Thomas A (TDb) Howard, OH, USA

1 CCD Image (7 September 2003) f/28×35cm SCT with a ToUcam

FRASSATI, Mario (MFr) Crescentino (VC), Italia

1 Drawing (14 September 2003) 400×20cm SCT

FUMEGA UCHA, Camilo (CFm) Ourense, España

1 CCD Images (11 September 2003)

f/20×31cm spec with a ToUcam

GRAFTON, Edward A (EGf) Houston, TX, USA

3 Sets of CCD Images (9, 11, 14 September 2003)

f/39, 34×35cm SCT with an ST-5C

HALL, George (GHl) 　Dallas, TX, USA

1 CCD Images (7 September 2003) 30cm SCT with a ToUcam

HANON, David (DHn) Ringgold, GA, USA

5 CCD Images (2, 9, 10, 11, 12 September 2003)

41cm spec with Sony VX-2000

HEATH, Alan W (AHt) Nottingham, UK

6 Drawings (1, 3, 4, 6, 10, 13 September 2003)

　180, 280×25cm speculum

IWASAKI, Tohru (Iw) KitaKyushu, Fukuoka, Japan

　　　　 19 Drawings (1, 3, 4, 6, 7, 8 September 2003) 400×21cm speculum

KARRER, Michael (MKr)　 St Radegund, Österreich

1 CCD Image (7 September 2003)

f/35×18cm Meade Refraktor with a ToUcam

KOWOLLIK, Silvia (SKw) Stuttgart, Deutchland

15 CCD Images (4, 3, 4/5, 8, 15 September 2003)

18cm Starfire Refraktor with a ToUcam Pro

KUMAMORI, Teruaki (Km) Sakai, Osaka, Japan　

25 CCD Images (1, ~4, 8, 9^#, 11, ~13, 14^#, 15 September 2003)

f/84×20cm Dall-Kirkham/f/30×60cm Cass^# with a ToUcam

^#Sakai City Observatory

LAU, Canon (CLa) Hong-Kong

6 CCD Images (9, 12 September 2003)

f/59×35cm SCT with a ToUcam

LAU, Patrick (PLa) Hong-Kong

3 Drawings (9, 12 September 2003) 300, 340, 400×25cm Dobsonian

LAZZAROTTI, Paolo R (PLz)　 Massa,Toscana, Italia

1 Set of CCD Images (6 September 2003)

　　　　　　　　　　18cm F/15 Mak-Cass with Astromeccanica KC381

MASSÓ MILLEIRO, Félix (FMr)　 La Corña, Galicia, España

1 CCD Image (12 September 2003) 25cm spec with a ToUcam

MELILLO, Frank J (FMl) Holtsville, NY, USA

　11 Red CCD Images (1, 6, 7, 8, 10, 11 September 2003)

20cm SCT with a Starlight Xpress MX5

MELKA, James T (JMl) St Louis, Mo, USA

1 CCD Image (7 September 2003)

f/130×31cm speculum with Canon D60

MINAMI, Masatsugu (Mn) Fukui, Fukui, Japan

65 Drawings (1, 2, 4, ~7, 9, 11, 13, 14, 15 September 2003)

480, 400×20cm F/12 ED Goto refractor*

*Fukui City Observatory, Fukui

MIYAZAKI, Isao (My) Gushikawa, Okinawa, Japan

3 CCD Images (2, 3 September 2003)

f/50×40cm speculum with ToUcam Pro

MORITA, Yukio (Mo) Hatsuka-ichi, Hiroshima, Japan

23 Sets of CCD Images (1, 6, 7, 8, 13, 14, 15 September 2003)

f/50×25cm speculum equipped with an ST-5C

MURAKAMI, Masami (Mk) Yokohama, Kanagawa, Japan

　　　　　27 Drawings (5, 9*, 10, 11, 12*, 13 September 2003)

320, 400×20cm spec, 450, 320×15cm spec*, 350×15cm refr*

*Kudan HS Observatory, Tokyo　

NAKAJIMA, Takashi (Nj) Fukui, Fukui, Japan

12 Drawings (6, 7, 8, 15 September 2003)

400×20cm F/12 ED Goto refractor*

*Fukui City Observatory, Fukui

NARITA, Hiroshi (Nr) Kawasaki, Kanagawa, Japan

12 Drawings (4, 5, 6, 11, 12 September 2003)

290, 400×20cm refractor

NG, Eric (ENg) Hong Kong

5 Sets of CCD Images (9, 11, 12 September 2003)

　　　　　　　　　　　　　 f/34×32cm Royce spec with ToUcam

OKANO, Kunihiko (Ok) Setagaya, Tokyo, Japan　

1 Set of CCD Images (5 September 2003)

31cm F/5 spec with an ST-7XME

PACE, Ben (BPc) Darwin, Australia

3 CCD Images (8, 13, 15 September 2003)

f/34×15cm Maksutov with a ToUcam

PARKER, Donald C (DPk) Miami, FL, USA

17 Sets of CCD Images (3, 7, 8, 10, 15 September 2003)

f/55, 59×41cm F/6 spec equipped with an ST-9XE

PARKER, Timothy J (TPk) LA, CA, USA

6 CCD Images (1, 14 September 2003)

15cm Jägers Achromat with a ToUcam

PAU, K C (KPa) Hong Kong

1 CCD Image (12 September 2003) 20cm spec with a ToUcam Pro

PELLIER, Christophe (CPl) Bruz, Ille-et-Vilaine, France

11 Sets of CCD Images (1, 2, 13, 15 September 2003)

18cm spec with a modified B&W ToUcam Pro

RODRÍGUEZ RAMÍREZ, Francisco A (FRd) Gran Canaria, Canary Islands, España

3 CCD Images (9, 15/16 September 2003)

20cm SCT with a ToUcam

SÁNCHEZ, Jesús R (JSc) Córdova, España

1 CCD Image (10/11 September 2003)

f/40×28cm SCT with a ToUcam

SHEEHAN, William P (WSh) Mt Hamilton, CA, USA

14 Drawings (2, ~7, 11, 12 September 2003)

487, 655×91cm refractor at the Lick Observatory

SHERROD, P Clay (CSr) Aso Sky Observatory, AR, USA

12 CCD images (4, ~11 September 2003)

f/35×41cm SCT with a ToUcam Pro

SIEGEL, Elisabeth (ESg) Malling, Danmark

8 Drawings (1, 4, 5, 7, 11, 12, 13, 14 September 2003)

270×20cm F/10 SCT

TAN, Wei-Leong (WTn) Singapore

2 Sets of CCD Images (3, 4 September 2003)

f/42×25cm Meulon with a ToUcam Pro

TATUM, Randy (RTm) Richmond, VA, USA

1 CCD Image (10 September 2003) 25cm spec with a ToUcam

TEICHERT, Gérard (GTc) Hattstatt, France

4 Drawings (1, 2, 4, 13 September 2003) 330×28cm SCT

TSUNEMACHI, Hitomi (Ts) Yokohama, Kanagawa, Japan

7 Drawings (13 September 2003)

260, 360×12.5cm Takahashi Fluorite refractor

VALIMBERTI, Maurice P (MVl) Melbourne, Australia

5 CCD Images (1, 3, 6 September 2003)

f/34×35cm SCT with a ToUcam Pro

Van Der VELDEN, Erwin (EVl) Brisbane, Australia

3 CCD Images (4, 5 September 2003)

f/31×20cm SCT with a Vesta Pro modified

WALLER, Skip (SWl) Dallas, TX, USA

1 CCD Image (13 September 2003)

f/50×25cm SCT (LX200) with a ToUcam Pro

WARELL, Johan (JWr) Tcuson, AZ, USA

　　　　　 2 Drawings (9, 11 September 2003) 260, 400×25cm SCT (LX200)

12 CCD Images (2, 3, 6, 9, ~13, 15 September 2003)

f/23×25cm SCT with a ToUcam

WILLIAMS, Bill (BWl) Ft Lauderdale, FL, USA

2 CCD Images (9 September 2003) 38cm Dob with ToUcam

WILLIAMSON, Thomas E (TWs) Alburquerque, NM, USA

1 CCD Image (2 September 2003) f/45×20cm spec with a ToUcam

WILSON, Barbara (BWs) Houston, TX, USA

2 CCD Images (7 September 2003)

20cm spec with a Nikon Coolpix 995

ZANOTTI, Ferruccio (FZt) Ostellato (FE), Italia

2 Sets of CCD Images (4 September 2003) 45cm spec with a ToUcam 　　　　　　　　　　　　　　　

reliminaries: Sorry to begin from personal affairs, but the present writer (Mn) re-started to observe at home at the Observatory of the Fukui City Museum of Natural History (at about 36.1°N while Naha at about 26.1°N) by the use of a 20 cm refractor; On 1 Sept, the angular diameter being still 25.0", the Martian surface looked fresh from Fukui, and starting from 12:10 GMT (ω=112°W), we were able to check the familiar details of such linear markings as Phasis and Agathodæmon; the south polar cap (spc) appeared to locate totally inside the disk. Another refreshed impression was that the surface was still dirty with the yellowish global haze. In addition to that we got the renewed impression that the white mists had quite prevailed equally at the morning terminator and the evening limb. The season λ=252°Ls implied the sub-solar latitude DS was high up nearly to 25°S, and hence the temperature in the daytime must have been quite different from the night-time temperature at the southern middle latitudes because the airborne particles absorb excessively the solar insolation (and emit in the night-time). It was so quite possible that further disturbances might be caused, and at least the settling of dust would have been further delayed.

From our side, the range from Solis L to Syrtis Mj was observed, while in Europe the surfaces were watched where Syrtis Mj prevailed to that angle M Sirenum stood. In America, the angles around from the prime Meridian to the region of M Cimmerium were observable. These three regions were not directly connected even at the opposition time. There lays vastly the Pacific Ocean between the American continents and Oceania/Asia region. On 1 September, the last observation we heard was CHAVEZ (RCv)’s at GA at 6:33 GMT, and the earliest observation in Oceania was made by VALIMBERTI (MVl) at Melbourne at 12:00 GMT, and so there is a gap of about 5 hrs. There is also a vast blank space between Oceania/Asia and Europe. On the day the present writer (Mn) quitted observing at 17:40 GMT (because the SW low direction from the observatory does not provide good seeing), and the time implies 5:40 pm at Greenwich and so it is apparent there could not be made any observation at that time in Europe. Really the earliest observation time in France was recorded 22:16 GMT by TEICHERT (GTc).

　Disk’s Limb, Morning/Evening Mists and the Southern High Latitudes: Since the phase angle ι is small as time is not far from the opposition, the both sides of the disk appeared unbiased. The water vapour being much toward northward as the summer solstice was near, the condensed fogs or mists were seen equally at dawn and evening limb quite rich. However the morning terminator as well as the evening limb side at the southern high latitude looked still quite dusty yellowish. For example, the image made by DENNERL (KDn) on 4 Sept (λ=254°Ls) at ω=244°W well shows the white hood at the npr as well as the white fog or frost at the northern limb and terminator sides, and at the same time the yellowish limb at the southern high latitudes. OKANO (Ok)’s detailed images on 5 Sept (λ=255°Ls) at ω=118°W also prove this phenomenon. The morning mist or frost will vanish visually as the place rotates into more inside, while the airborne yellowish haze will survive even at noon.

The morning mist or fog just after the daybreak appeared slightly different from area to area: In this sense the thick fog at the area of Solis L was quite interesting. For instance, on 2 Sept (λ=253°Ls) HANON (DHn)’s image at ω=356°W shows the mist over Solis L beautifully (see also the yellowish haze at the southern high latitudes). Then WILLIAMSON (TWs)’s images at ω=030°W shows it quite deep inside the disk. Otherwise, PELLIER (CPl)’s images at ω=258°W ~ 263°W depict the thick morning fog at Æria (as well SIEGEL (ESg)’s drawing on 1 Sept (λ=252°Ls) at ω=260°W shows this), and AKUTSU (Ak)’s images at ω=105°W ~ 144°W show also morning mists at different region. WARREL (JWr)’s images on 3 Sept (λ=253°Ls) at ω=006°W show the thick nph as well as the morning mist. VALIMBERTI (MVl)’s images at ω=107°W/109°W show specifically an interesting configuration of the morning mist. This case as well as the morning mist over Solis L will be mentioned again later. The Solis L case in the latter half of the period is compiled as follows: KUMAMORI (Km)’s on 12 Sept (λ=259°Ls) at ω=028°W; Ak’s on 13 Sept (λ=260°Ls) at ω=017°W, 027°W; MORITA (Mo)’s on 14 Sept (λ=261°Ls) at ω=011°W, 021°W, 031°W; Ak’s on 15 Sept (λ=261°Ls) at ω=019°W and so on.

As to the evening mist, the descriptions by Ak on 2 Sept (λ=253°Ls) at ω=105°W~144°W and by Km on 3 Sept (λ=254°Ls) at ω=097°W, 124°W are good (equally with the morning mist). At the latter part of the period, ι increased and the balance became broken in general. We finally note that the Arsia white cloud still prevailed this period.

Southern High Latitudes and Wine-Coloured Areas: The present writer (Mn) observed around 5 Sept (λ=255°Ls) and 6 Sept (λ=256°Ls) that the southern circumpolar region had slightly decoloured and quite showed a sandy tint. On 5 Sept ω=079°W ~ 108°W, he even noted that it was impossible to detect the ruddy tint. On 11 Sept (λ=259°Ls) however he observed at ω=036°W, 055°W et al the area showed a ruddy colour, while at ω=084°W the area was rather brownish. It was thought so that the water supply from the spc had been rather weakened and/or the yellow haze was rather strong. On 9 Sept (λ=257°Ls), another interesting observation was made at ω=061°W, though the seeing condition was not so preferable after the thundershower, that the area at the morning higher latitudes around the area from Aonius S to Depressio Pontica and further was quite dark, darker than the preceding Solis L, and then at ω=080°W, 092°W, the area including Solis L looked quite brownish or wine coloured. In contrast to this, the area of Auroræ S was rather dark bluish. On the day, KUMAMORI (Km) took a good image at ω=044°W by the 60cm Cassegrain, and Ak also made a set of images at ω=050°W, 058°W: They all prove that a tongue-like region from the area from Aonius S to Coracis Portus to Solis L crossing Thaumasia Fœlix was popped out of the large morning mist showing vividly a dark wine colour. This configuration is evident in B images, and so the exceptional colour difference was caused by a de-concentration of the water condensates mingled with the airborne dusts. The images by PAU (KPa) at ω=042°W and by NG (ENg) at ω=046°W~067°W on 12 Sept (λ=259°Ls) also show the de-concentration similar to that seen on 9 Sept, but this case, Solis L looked to be partially covered by a white mist. Anyway the de-concentrations or uneven irregular configurations of the floating matters seem to make some areas to be wine–coloured.

This phenomenon seems not particularly rare, and in fact is seen for example on an HST image taken on 14 December 1990 (λ=349°Ls, this year Mars was at opposition on 27 November while closest on 20 November) here cited (from the Site of Chris PELLIER (CPl) quoted in CMO #276 Report #11). Since this was taken much later in season, similar uneven configuration should be observable hereafter also. Note that the de-concentration of misty expansion in the HST image also occurred from Argyre to Solis L thru Thaumasia.

Canon LAU Phenomenon: The first observation of the de-concentration on 9 September was slightly early to Hong-Kong, while the second on 12 September was too late in Japan to watch. On 9 Sept (λ=257°Ls), however, Canon LAU (CLa) at Hong-Kong chased the surface after Ak’s cases further, and found at ω=088°W, 096°W another interesting phenomenon: At the very end of the de-concentrated tongue there was seen a darker wine-coloured patch. This was weakened however at ω=127°W (though images at ω=106°W and 116°W are lacking). Fortunately ENg shot at ω=117°W to supplement, and showed that this comes down from the M Sirenum (CLa’s image at ω=066°W suggests it started from around Araxes). The darker wine-coloured patch is positioned around at Ω=160°W, Φ=10°N~10°S: The place is not particularly dark area, but according to the MOLA image, it corresponds to a suddenly lowered land. MGS’s map also suggests the spot.

This spot was also detected by several other observations: Early on 3 Sept (λ=253°Ls) MVl’s image at ω=107°W already shows it, and Mo’s as well as ASADA (As)’s images on 7 Sept (λ=256°Ls) at ω=095°W, 105°W, and Km’s on 8 Sept (λ=257°Ls) at ω=097°W, 113°W all suggest the same temporary spot.

　Trinacria to Hellas: There can be witnessed a blurred light column from Trinacria to the eastern part of Hellas straightforwardly on the images of CPl made on 1 Sept (λ=252°Ls) at ω=307°W, and this is also seen on the images made on 3 Sept (λ=254°Ls) by KOWOLLIK (SKw) at ω=246°W ~ 256°W, and by DIJON (JDj) at ω=247°W. We may also say that the images by DOBBINS (TDb) on 7 Sept (λ=256°Ls) at ω=308°W and by DHn on 11 Sept (λ=258°Ls) at ω=261°W also suggest the vague different coloured column. It is not known what it is made of, but it may be a deposit made from a fallout since it seems to stand still (maybe from an earlier period) days and nights. More detailed image was given by GRAFTON (EGf) on 11 Sept (λ=258°Ls) at ω=288°W in which the blurred part is not remarkable. Surely markings including others look not so different in density and configuration from those observed in August. Don PARKER (DPk) also gave detailed images on 10 Sept (λ=257°Ls) at ω=271°W, 284°W, while the G and B images show a bit a trace of the vague column implying the place was covered by a contaminated matter. Here we show EGf’s image (part) on 14 Sept (λ=260°Ls) at ω=249°W to compare it with the one on 3 Sept by JDj at ω=247°W. We add a corresponding partial image made by the MGS in 2002 after the 2001 dust storm. This may prove that a part of M Hadriacum has slightly recovered darker to the north of Hellas after the devastation by the 2001 dust fallout.

Osidis Promontrium?: A light spot is seen at the east coast of Syrtis Mj on the image made by DHn on 11 Sept (λ=258°Ls) at ω=261°W. This is also checked on the images by SWl on 13 Sept (λ=260°Ls) at ω=264°W, by CHAVEZ (RCv) at ω=272°W, and by EGf on 14 Sept (λ=260°Ls) at ω=249°W etc. This time it has a whitish tinge, while it is positioned at the same place as that found on 24 June (λ=209°Ls), and on 28, 29 July (λ=231°Ls). The one on 24 June was the dust germ that might have been connected with the June/July dust. Classically this may correspond to Osidis Promontrium, though the present one is not always constantly visible. Remark however that the dust spotted by the MGS on 29 June 2003 occurred in a slightly different place at the western part of Libya.

Decay of Thyles Mons: The circumpolar area around Thyles Mons has been the most interesting place to watch at this period. From Oceania/Asia the place was seen near at the CM on 1 September when the planet was high up at meridian and so the area was chased rather in details. The ccd images by MVl made on 1 Sept (λ=252°Ls) at ω=110°W, 146°W are most suggestive. Thyles Mons exists as a weakened but still explicit projection and beyond it there is seen an expansion of a yellowish dusty marking. The latter seems to come down faintly to the east end of M Sirenum. BUDA (SBd)’s images at ω=130°W (134°W) also fulfilled the gap to show this phenomenon but less colourfully. In Japan the following angles were caught for example at ω=157°W by Mo, at ω=161°W et al by As, and at ω=168°W by Km where every shows the dusty expansion. On 2 Sept (λ=253°Ls), MIYAZAKI (My) gave a good image at ω=136°W (corresponding to the angle he drew in 1988 as cited previously and also will be cited below again). Otherwise, Ak took at ω=116°W, 127°W, 139°W, and Km at ω=164°W. On 3 Sept (λ=154°Ls), MVl again obtained a good image at ω=109°W which can be compared with the one on 1 Sept at ω=110°W: The dust expansion looks to have done no definite change. On 3 Sept, Km also gave a good image at ω=124°W, and As took at ω=136°W and 146°W. TAN (WTn) shot then at ω=157°W, and this can be compared with the image by him on the following 4 Sept (λ=254°Ls) at ω=154°W: As well no explicit change on the expansion. On 4 Sept Van der VELDEN (EVl) already gave images at ω=123°W(126°W). Ok’s images on 5 Sept (λ=155°Ls) at ω=118°W still definitely show Thyles Mons and As’s at ω=130°W shows the outskirt expansion of the dusty matter. We could manage to watch the area until the day, and on 6 Sept (λ=256°Ls), the present writer (Mn) was scarcely able to catch a glimpse of Thyles Mons at ω=109°W (15:00 GMT) under poor seeing. On 9 Sept (λ=257°Ls), ENg’s image at ω=117°W looks to show a bit of a remnant, but CLa’s one at ω=127°W does barely not. We should however remark that these images still show explicitly the expansion of the decayed dusty marking. In Europe, on 13 Sept (λ=260°Ls), CPl took the angle at ω=144°W where we should say it is difficult to spot an explicit Thyles Mons. CPl took similarly the angles ω=123°W, 145°W on 15 Sept (λ=261°Ls). On the same day, DPk produced the image at ω=207°W, the very angle which we featured previously, and here a bit of Thyles Mons is still pinned down at the lhs end. This depends on the resolution power. The dusty expansion must have remained as a deposit.

As to Thyles Mons at λ=254°Ls, we once dealt with its 1988 case in comparison with the case in 1971 in CMO #087 (25 May 1990 issue) at p0731 as “1988 CMO Note (12).” Figures here presented are those originally cited there; the first one (Fig.1) is the same drawing by MIYAZAKI (My) on 17 August 1988 that we quoted in the preceding report. Figure 2 is also My’s drawing on the following day (λ=255°Ls) at ω=149°W, φ=20°S. My observed that the dust expansion outside gradually faded on the following days. The third one (Fig.3) is cited from the S&T January 1972 issue at p20 and a drawing of Gérard de VAUCOULEURS made on 14 September 1971 (λ=254°Ls) at ω=150°W, φ=15°S. The season corresponded to ours on 6 September 2003. De VAUCOULEURS commented “A small stationary cloud was observed between 14^th and 17^th September over the western part of Thyle I. … Nearly as bright as the martian continents, this cloud … was elongated from north-northeast to south-southwest. It was visible not only in white light but through red, orange and green filters, and it hardly changed in shape or position during three days of observations.” He seemed to have failed to detect Thyles Mons any longer on 17 September (λ=256°Ls) though the “cloud” was still evident, and so the recession process must have been slightly rapid compared with the cases in 1988 and 2003. De VAUCOULEURS used a 150cm telescope (down to 125cm) at the LPL, Arizona, with a magnification of 525. (The 1971b great dust cloud was given rise to a bit later on 22 September 1971.) The comments made by the present writer (Mn) on the occasion (in 1990) were that the “cloud” could have never been a white cloud, and must have been a trace of a dust projected from Thyles Mons caused by its fast thawing: it was already known the Viking had detected otherwise a dust cloud near the edge of the spc at around λ=251°Ls, and the “three days” should have been longer; just it was because it was traced only from Arizona. At the period of the rapid sublimation of CO2, the spr becomes governed by a high pressure atmosphere so that outward bursts of air cause several projections from the polar edge.

Since the MGS has been much interested in the outburst of dust from the north polar region, and so we suppose they could have never missed the chance to trace the decay of Thyles Mons as a phenomenon in question ever since De VAUCOULEURS’ observation at the LPL, but unfortunately we have not big ears.

　Argenteus Mons and Rima Angusta: Argenteus Mons, once very conspicuous, looked down to be normal. No decay was observed. Furthermore we have few images showing the contour of the spc in a good balance though any image at around ω=040°W suggest Argenteus Mons. Especially only a few that shot the rift following Argenteus Mons. Rima Angusta was visually caught around 6 and 7 Sept (λ=256°Ls), as observed by IWASAKI (Iw) as well as by Mn, but no ccd image was successful in Japan. However the images on 6 Sept (λ=256°Ls) by SBd at ω=074°W, and by MVl at ω=089°W suggest the rift. ENg’s images on 9 Sept (λ=257°Ls) at ω=117°W looks to show a projection from the rift end, while the image by CLa does not, and ENg’s another set on 11 Sept (λ=259°Ls) at ω=065°W shows that the projection seems to come from the following edge of the snow lump. Rima Angusta was rather evident previously, for example it was shot on the image by SKw on 19/20 Aug (λ=245°Ls) at ω=065°W.

　Novus Mons and Its Preceding Area: Novus Mons was still present explicitly even at the end of this period (λ=260°Ls). It was lucky for TDb to be able to catch it by his first shot on 7 Sept (λ=256°Ls) at ω=308°W. Any image that took Novus Mons near the CM might be all successful, and as well our MURAKAMI (Mk) was visually able to catch it clearly on 11 Sept (λ=259°Ls) at the angle ω=031°W after these 15 years (his last shot of Novus Mons on TP2415 by a Nikon 10cm refractor was made on 29 August 1988 at λ=262°Ls when δ=21.8" --- cf CMO #116 p1017). Among many, the faint description of WALLER (SWl) from an oblique angle at ω=264°W on 13 Sept (λ=260°Ls) is fantastic. From the similar angles WILLIAMS (BWl) gave further interesting images on 9 Sept (λ=257°Ls) at ω=269°W, 285°W in which at the already vanishing preceding area of Novus Mons there still remains a small isolated piece of island. Standard series of images made by DPk on 8 Sept (λ=256°Ls) at ω=265°W(268°W), 278°W, 278°W(282°W), 287°W(289°W) show Novus Mons quite well as well as the isolated BWl point (DPk’s at ω=287°W corresponds to BWl’s). EGf’s images on 9 Sept (λ=257°Ls) at ω=269°W, and on 11 Sept (λ=258°Ls) at ω=283°W also show well Novus Mons.

ill SHEEHAN (WSh) Observed at the Lick: SHEEHAN (WSh) stayed at Mt Hamilton, California, from 28 August to 12 September together with Tony MISCH, Laurie HATCH, & Rem STONE and observed Mars securing a lot of drawings made by the use of the famous 91cm refractor at the Lick Observatory: This refractor is the one used by E E BARNARD for example in 1894 when P LOWELL was first chasing the planet at the same time at Flagstaff, and their intension of Bill’s team must have been to decode BARNARD’s documents referring to the real images inside the eyefield of the big refractor. A file of work was compiled as the Two Weeks on Mars in the URL:

http://mtham.ucolick.org/public/TwoWeeksOnMars/

During the fortnight, WSh watched the surfaces from ω=084°W eastwardly to ω=265°W. The angular diameter was still perfect, and the period corresponded to the good seeing season at Mt Hamilton. We don’t exactly know how much Bill had already practised in observing Mars (we know he gave several good drawings at the Pic du Midi), but we can readily judge the 91cm refractor (maybe sometimes reduced to 50cm) gave him quite details from the outset. He detected several minor dark spots following Solis L, and the complex structure around Eos including the set of Electra and Orestes as well as Juventæ Fons. Furthermore he depicted Aurea Cherso clearly (2 Sept (λ=253°Ls) at ω=040°W). We suppose WSh must have minutely investigated the area of Edom, and saw as byproducts such a minor marking as Brangæna and the new big marking of the expanded M Serpentis after the July 2003 dust (7 Sept (λ=256°Ls) at ω=326°W). Huygens Crater was spotted (11 Sept (λ=259°Ls), and there seem to be visible several spot-like shadows inside M Tyrrhenum to the 91cm eye. N Alcyonius was always easy to Bill, and we suppose the fading of Thoth-Nepenthes must have looked the same as the time of BARNARD. Brangæna, Electra and Orestes are those of the new nomenclature given by Shiro EBISAWA, and the latter two were believed to have found first on SLIPHER’s images in 1939, while according to the documents decouverts at the Lick cited in the above URL, BARNARD already looked to have detected the twin markings of Orestes and Electra in 1894.

In contrast to the limb-lacking images of ccd, WSh’s drawings quite clearly show that the spc was totally inside the disk. WSh saw a vanishing Thyles Mons on 29 August (λ=250°Ls) at ω=084°W.

Under a permission we here cite a Laurie Hatch photo of William SHEEHAN at the eyepiece of the 91cm wearing a T-shirt of another William S (© 2003-2004 Laurie Hatch, all rights reserved. Nobody should use or reproduce without her permission). Laurie HATCH is a professional photographer at the Lick and, as remarked above, joined the Two Weeks observation team. Her excellent colour drawings of the red planet are also found on a page of the above URL.

mpressives: Without hesitation, Canon LAU (CLa)’s set of images on 9 Sept (λ=257°Ls) at ω=061°W ~ 127°W should be praiseworthy. The file is good in the sense it is composed of a long series of images showing the de-concentration of the morning mist. Another image that is very impressive is the one made by VALIMBERTI (MVl) on 3 Sept (λ=154°Ls) at ω=107°W (109°W). The descriptions of the inside of the spc, the last stage of Thyles Mons with its ochre colour surroundings as well as the localised morning mist are excellent. VALIMBERTI (MVl)’s image of Aurea Chersonesus on 6 Sept (λ=256°Ls) at ω=089°W should be one of the best images secured during this apparition (here shown the part).

he next issue shall treat the observations made in the second half of September 2003 from 16 September (λ=262°Ls, δ=23.4") to 30 September 2003 (λ=270°Ls, δ=20.9").

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