2001 Mars Observation Reports -- #14--

OAA MARS SECTION

CMO Mars Observations


in in the First Half of August 2001
from 1 August 2001 (206Ls) to 15 August 2001 (214Ls)
based on the article published in CMO #250 (25 August 2001)

 


Masatsugu MINAMI, Director of the OAA Mars Section



 

T

HE apparent diameter of the planet decreased from 17.0 arcsecs to 15.2 arcsecs during the period. The central latitude varied from 7N to 5N. The season proceeded from 206Ls to 214Ls. The season does not seem to mean anything because of the dust veiling, while the altitude of the Sun on the southern hemisphere is steadily rising (Ds was from 11S to 14S). The phase angle was deep from 35 to 40: The south circumpolar region is governed by the midnight Sun, while the opposite circumpolar region including the north polar cap has no Sunbeam whole day.

 

We are thankful to the following observers who contributed to the CMO this time:

 

AKUTSU, Tomio (Ak) Tochigi, Japan

2 Sets of CCD Images (3 August 2001)

f/70 32cm spec with a Teleris 2

 

BARNETT, John H (JBn) VA, USA

2 Drawings (22 July; 3 August 2001) 270, 360x 18cm refractor$

 

BIVER, Nicolas (NBv) Versailles, France# / Noordwijk, Netherlands

6 Colour Drawings (1, 5, 9, 11#, 12#, 14 August 2001)

300x 20cm spec / 330x 26cm spec#

 

CAVE, Thomas R (TCv) Long Beach, CA, USA

1 Drawing (5 August 2001) 400x 33cm speculum

 

HEATH, Alan W (AHt) Nottingham, UK

1 Note (1 August 2001) 160, 8020cm SCT

 

HIKI, Toshiaki (Hk) Minowa, Nagano, Japan

5 Drawings (3, 9, 13 August 2001) 430x 22cm speculum

 

ISHADOH, Hiroshi (Id) Naha, Okinawa, Japan

10 Drawings (4 ~ 8, 10, 11, 13, 14, 15 August 2001)

290, 340, 400x 31cm speculum

 

ISHIBASHI, Tsutomu (Is) Sagamihara, Kanagawa, Japan

3 Colour Images (23, 30 July; 3 August 2001)

31cm f/6.4 spec, Fujichrome 400F

 

KUMAMORI, Teruaki (Km) Sakai, Osaka, Japan

2 CCD Colour Images (11, 13 August 2001)

20cm Dall Kirkham / 65cm Zeiss refractor with a Sony PC-5

 

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

3 CCD Images (1, 9 August 2001) 20cm SCT with a Starlight Xpress MX5

 

MINAMI, Masatsugu (Mn) Naha, Okinawa / Fukui*, Japan

83 Drawings (1 ~ 11, 13*, 14*, 15* August 2001)

420, 530x 25cm speculum / 400, 600x 20cm refractor*

 

MOORE, David M (DMr) Phnix, AZ, USA

3 Sets of CCD Images (3, 5, 6 August 2001)

f/40 36cm Cass with an Astrovid 2000 video camera

 

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

22 Sets of CCD Images (1, 3, 4, 8, 9, 12 ~ 15 August 2001)

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

 

MURAKAMI, Masami (Mk) Fujisawa, Kanagawa, Japan

4 Drawings (14 August 2001) 320x 20cm speculum

 

NAKAJIMA, Takashi (Nj) Fukui, Japan

18 Drawings (7, 13, 14, 15 August 2001) 400x 20cm refractor*

 

NARITA, Hiroshi (Nr) Kawasaki, Kanagawa, Japan

5 Drawings (3, 4, 9, 14 August 2001) 320,400x 20cm refractor

 

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

1 Drawing (7 August 2001)

245x 41cm spec with filters: W25, 23A, 58, 15, 38A & IL

9 Sets of CCD Images (8, 9, 12, 13 August 2001)

f/36, 44.2 41cm Newtonian equipped with a Lynxx PC

 

SCHMUDE, Richard W, Jr (RSc) GA, USA

9 Drawings (22, 23, 31 July; 2, 3, 4, 7, 9, 13 August 2001)

230, 209x 10cm refractor

 

TAN, Wei-Leong (WTn) Singapore

14 Sets of CCD Images (5, 6, 12, 13 August 2001)

f/16 28cm SCT equipped with an ST-7E

 

TEICHERT, Grard (GTc) Hattstatt, France

6 Drawings (1, 11 ~ 15 August 2001) 330, 310x 28cm SCT

 

TSUNEMACHI, Hitomi (Ts) Naha, Okinawa / Yokohama, Japan

24 Drawings (1 ~ 4 August 2001) 420, 530x 25cm speculum

 

VALIMBERTI, Maurice (MVl) Viewbank, Victoria, Australia

4 Sets of RG(IR) Images (13 August 2001)

f/85x 15cm refra with a TC245 based camera

 

$ Richmond Astronomical Society Ragland Observatory

Hida Observatory, Kyoto University

*Fukui City Observatory

 

The Yellow Cloud and the Dark Markings :

  From Japan some of us was able to on the watch every day and observed the surfaces from LCM=315W eastward to LCM=110W during the period. The yellow cloud was still globally persistent, and there were few signs of subsiding; Just we may say the major yellow cloud has become more uniform globally, and the density has been slightly decreased. Aspects of some dark markings are as follows:

 

M Cimmerium :
  It was previously proved that the western part of M Cimmerium once disappeared (on 30 June, for example the images by AKUTSU (
Ak)) but the place soon refigured strangely as a large dark patch on 3 July (10 days since the emergence of the storm) as shown on the images by MORITA (#248 p3071). The patch survived on the images by MOORE (DMr) at LCM=226W on 27 July (34 days). The angle came into sight in Japan around from 5 August (43 days): At Okinawa, the angle LCM=220W visited at 19:50 JST (10:50GMT) on the day. The eastern part of M Cimmerium also reappeared, and the junction area with the western patch was concave from the south nearly at 210W; reminiscent of the image of DMr. The angle was observed until 10 August (Mn observed 6 Aug at 10:50GMT LCM=211W, 7 Aug at 11:30GMT LCM=212W, 8 Aug at 12:10GMT LCM=212W, 9 Aug at 12:50GMT LCM=213W, 10 Aug at 13:30GMT LCM=213W, and then finally on 11 August at 14:10GMT (23:10 JST) LCM=213W chez ISHADOH (Id). Mn left Okinawa on 12 Aug): One of the results was that the configuration stayed almost the same until 8 August (46 days), but from 9 August (47 days) it became different and it looked M Cimmerium began to recover. This angle was the same as the one set by Mo on 1 ~ 4 July (#248 p3071). The western part was no more so dark. Mo obtained the images on 8 August and 9 August at LCM=222W. The former looks similar to DMr's. On the other hand TAN (WTn) in Singapore secured images on 12 August (50 days) from LCM=178W to 230W (see LtE); and the image at LCM=224W is comparable with Mo's image and shows the M Cimmerium area has been more levelled and the concave part has been also weaker, though Id observed that the part is dusty bright on 4 August (42 days) in the evening at LCM=250W.

 

M Sirenum :
  At the same time, M Sirenum began to slightly recover. On 10 Aug (48 days) at LCM=194W, however, there was a medium-sized bright dusty patch in Electris to the south of M Sirenum, and so still an activity on the continents: Comparable with an image of
WTn on 12 August at LCM=193W.

Olympus Mons :
  This is not any dark marking; but at present because of the bright cloud sea around the summit, the summit appears as a brownish dark spot. At Naha, it came into sight from 9 August (47 days) (until LCM=193W). On 11 August,
Id caught it at LCM=206W, on 12 August, Mo at LCM=190W and WTn at LCM=193W, on 13 August, KUMAMORI (Km) at LCM=139W, HIKI (Hk) at LCM=153W/163W, Mo at LCM=165W. In Australia VALIMBERTI (MVl) shot at LCM=122W ~ 170W on 13 August; the spot is clearly shot also in G. MURAKAMI (Mk) watched the summit on 14 August (52 days) from LCM=122W to 151W, and Mo from LCM=144W to 168W. The present writer (Mn) checked it from 8 August to 11 August at Naha, and after returned home watched from 13August to 15 August. On 14 August (52 days, the phase angle is 40) Mn together with NAKAJIMA (Nj) watched continuously from LCM=117W (18:30 JST) to LCM=176W (22:30 JST). From the morning side, the brownish spot was visible, but more apparent after passing the CM. At around LCM=145W, the dark spot was very clear and we felt we were seeing as if a transit of Mercury across the Sun surface. The LMT was about 10h AM. Mo's images also show it much clearly at around LCM=150W. On the day Id watched it at LCM=142W: He described it as a round spot, but saw it deformed near the limb 13 Aug at LCM=178W. Arsia Mons was the same as before, but Ascrus Mons looked weaker. 15 August, Mo, Nj and Mn observed.

 

On Don PARKER's images :
  Don (DPk)'s potential energy continues to work: His images taken 8 August (210Ls, 46 days) at LCM=047W/050W, 066W/067W, 077W are excellent and will prove to be very important in future when we shall investigate the configuration of the low dust cloud over such dark markings as M Erythrum, Auror S and Margaritifer S. The Red images on 12 August (50 days) at LCM=022W, 027W, and on 13 August at LCM=359W show faintly S Meridiani and Margaritifer S, but we could not say they are really visible in Int: S Meridiani on the images are much weaker than the one on the DPk images on 7 July (16 days).


  The North Polar Hood :
  The Sun moved to the south, and the north polar hood (nph) began to loose it brightness from mid-July and we sometimes saw the underneath through the cloud. We talked every day with Id and TSUNEMACHI (Ts) on this phenomenon at Naha. As August came in, the nph, though it still showed an activity inside, became weaker in general. Around 1 August (206Ls, 39 days) the Japanese observers watched the surfaces where Syrtis Mj presented. Utopia was dark and large visible as if divided the nph. Utopia was watched from around 26 July (33 days) near the CM, and the nph every day looked different against Utopia. This is proved from the sketches by Mn made 30 July at LCM=298W, 31 July at LCM=299W, and 1 August at LCM=297W. Ts's drawings at LCM=274W/273W made one week from 30 July to 4 August also show the variations of the nph. Ts described 2 August (40 days) that the nph was weak. On 3 August, Hk observed at LCM=244W/253W that the nph was dull and inactive, and Ts observed at LCM=254W~ that the nph was faint. Id described 4 August (42 days) at LCM=250W that the nph was dim, and 5 August (43 days) at LCM=245W that it was blue-whitish but much less bright. Mn however observed partly a brighter patch at the morning side on 2 August; On 3 August at LCM=278W the morning brim partly looked brighter (Ts pointed out this doubled structure of the nph at LCM=264W/274W already), and thus the nph these days looked decayed and divisive in general. On 9 August (211Ls, 47 days) a southward protrusion of the nph at the morning area at LCM=223W ~ 232W was seen; the part being faint and off-white. Mo's images also prove that the nph became fainter and more declined than before: The nph on Mo's RGB images made 8 August (210Ls, 46 days) at LCM=223W is faint. The images by DPk on the same 8 August at LCM=047W, 067W and 077W, excellent images as cited above, show that the density of the nph is not uniform: there is a large cloud patch at the morning side and otherwise we can find a small white fleck to the north of M Acidalium but other areas are rather just misty. The fleck is reminiscent of the npc, but at present the npc should be inside the defect of illumination. DPk's succeeding images on 9 August at LCM=043W show that it has diffused. the central latitude is 6N on the day.

 

  The Change of the Dark Fringe of the NPH :
  The dark band at the fringe of the nph had long been quite dark in a tint of blue-black, while it became inactive and fainter as the nph became inactive, and thus the boundary of the nph has become indistinct. On 4 August (208Ls, 42 days), the fringe was quite dull from our side, though there followed a darker part.

 

  The South Polar Cap and Its Morning Cloud/Frost :
  Around 1 August, the central latitude is 7N and so the tilt was not so declined, but the south polar cap (
spc) lacked its possible appearance; different to the anticipation made at #241 p2953. Notably however, we had long watched more vividly a thick morning cloud following the spc (as stated in #249), and this morning cloud/frost must have been of the same kind as the one shot by the HST on 26 June (185Ls). At that time this was rather weak if seen telescopically (as shown on VALIMBERTI (MVl)'s images on 17 June (180Ls) at LCM=326W, 18 June at LCM=340W; see below). It was also not so strong when the major dust storm started. As far as the present writer observed, the morning cloud became distinct around from 7 July (191Ls, 14 days) and from 9 July (16 days) it became quite evident. Mo's images on 7, 9 and 10 July prove also this. His image does not show it until 4 July. Even after the yellow cloud utterly covered the globe, it repeated every day and for example DPk's images on 13 July (20 days) show clearly the morning cloud. In mid-July, it was very distinct since the part showed a dark fringe, and as was noted in #249, it showed a bluish dark colour when it was adjacent to Depressiones Hellespontic. It was possible it contained a frosty matter. This morning cloud/frost was still present on 1 August (39 days) (checked by Ts, Mo, Mn and others). AKUTSU (Ak)'s images made 3 August (41 days) at LCM=244W, 253W, and Mo's at LCM=272W also show this. Ts visually checked it until 4 August. However it became gradually weaker: Id drew it gradually fainter from 4 August to 7 August, and after 10 August the cloud did not appear on his drawings. Mn also from 8 August (210Ls, 46 days) did not often catch it, though 10 August (48 days) at LCM=213W, it showed up with a distinct fringe. On Mo's B images, it became fainter around from 8 August and roughly speaking disappeared around from 12 August (50 days). MOORE (DMr)'s images 6 August at LCM=113W clearly show it, and DPk's images on 8 August (aforementioned) also show it a bit, but DPk's images on 12 August does not. Thus the morning cloud should be said to have begun to thickly prevail as the global yellow cloud became stable, lasted for 45/50 days and diffused because of a possible change of temperature at the same time as the nph became inactive. We finally note there is witnessed a bright white fleck just outside the spc fringe on DPk's images on 8 August and 9 August; the position being possibly at 030W ~ 040W.


  THE following are the additional observations received afterward:

ISHIBASHI, Tsutomu (Is) Sagamihara, Kanagawa, Japan

8 B&W Photos (13 April; 12, 13, 20 May; 2, 27, 28 June 2001)

31cm f/6.4 speculum, HIE, NP400P, TP

 

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

4 Sets of Drawings (25 June; 8, 9, 12 July 2001)

325, 340, 430x 41cm speculum

 

VALIMBERTI, Maurice (MVl) Victoria, Australia

3 Sets of CCD Images (17, 18 June 2001)

f/82 15cm refractor with a Cookbook TC245

  ISHIBASHI (Is)'s photos by the use of TP1415 and HIE on 27 June at LCM=250W and 28 June (4 days) at LCM=245W might be emulsion images having a scarcity value of the present 2001 yellow cloud.

  DPk's drawings made 8 July (16 days) at LCM=010W and 9 July (17 days) at LCM=334W(1:45GMT) show S Meridiani just before it was covered by the thick dust cloud. The former also shows a strong dusty flow from Thaumasia to Auror S. After one hour twenty minutes on 9 July he produced important ccd images at LCM=354W (3:06GMT) as reported before:

  On the day DMr observed at LCM=023W (5:04GMT), 028W, MVl at LCM=084W (9:15GMT)/090W, and at Naha (Mn) from LCM=110W (11:00GMT) to LCM=183W (16:00GMT); (WTn in Singapore at LCM=164W(14:41GMT) ~ 170W(15:09GMT.)
  The images by VALIMBERTI (
MVl) on 17 and 18 June are excellent made at LCM=310W, 326 W (former) and at LCM=340W (latter): These images by a 15 cm refractor are really comparable with the HST image on 26 June as to the airborne dust at the evening limb, the nph, the spc and its following morning cloud.


T

he next issue (#251) shall review the observations during a one-month period from 16 August (215Ls) to 15 September 2001 (234Ls). CMO #252 shall be regularly published 25 October 2001.
  We hope every set of CCD images is emailed in a
jpg file with a file name beginning with the observer's name to vzv03210@nifty.com as well as to cmo@mars.dti.ne.jp. Drawings are preferred to be sent in an A4 sized format with just one drawing on one sheet.


Reports will be acknowledged if air-mailed to M MINAMI at Mikuni
(ask the mail-address through vzv03210@nifty.com ) .


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