2001 Mars Observation Reports -- #12--

OAA MARS SECTION

Mars Observations
in the First Half of July 2001
from 1 July 2001 (188Ls) to 15 July 2001 (196Ls)
based on the article published in CMO #248 (25 July 2001)


by Masatsugu MINAMI, Director of the OAA Mars Section



T

HE planet now suffering from an out-of-season dust cloud showed the apparent diameter of 20.5 arcsecs on 1 July (188Ls) while it went down to 19.2 arcsecs on 15 July (196Ls). Usually a detailed image is expected on such an occasion, but this time a global observation was needed. The central latitude went up from 6.1N to 7.3N, and the phase angle was 15 to 26. The surface might loose the meaning of its season because of the rapid development of the yellow cloud, but the nph was active in accordance with the season. The trend of the spc was also interesting.

  We acknowledge receipt of the observations this period as follows:

AKUTSU, Tomio (Ak) Tochigi, Japan

4 Sets of CCD Images (4, 10, 15 July 2001) f/70 32cm spec with a Teleris 2

 

ASADA, Tadashi (As) Munakata, Fukuoka, Japan

12 Sets of CCD Images (1, 2, 4, 8 July 2001) 30cm spec equipped with a Lynxx PC

 

BARNETT, John H (JBn) VA, USA

2 Drawings (1, 11 July 2001) 270, 360x 18cm refractor$

 

BATES, Donald R (DBt) Mt Locke/Houston, TX, USA

2 Colour Images (8, 9 July 2001) f/120 25cm speculum, Elite Chrome 200

 

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

2 Colour Drawing (12!, 14 July 2001) 190x 20cm speculum! / 330x 26cm speculum

 

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

2 Drawings (2, 5 July 2001) 390, 400, 550x 33cm speculum

 

CIDADO, Antnio Jos (ACd) Oeiras, Portugal

6 Sets of CCD Images (4/5, 6 July 2001) 25cm LX200SCT with an ST-5C + AO

 

FALSARELLA, Nlson (NFl) Sao Jose do Rio Preto - SP, Brasil

9 CCD Images (6, 9, 10 July 2001) 20cm speculum + AVA ASTROVID 400

 

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

3 Sets of CCD Images (5, 7, 11 July 2001) f/60 35cm Celestron SC with an ST6

 

HEATH, Alan W (AHt) Nottingham, UK

3 Drawings (1, 3, 4 July 2001) 200x 20cm SCT

 

HIGA, Yasunobu (Hg) Naha, Okinawa, Japan

38 Video Images (1, 2, 3, 6~10, 12, 13, 14 July 2001)

25cm f/6.7 speculum equipped with a Sony VX-900

 

HIKI, Toshiaki (Hk) Minowa, Nagano, Japan

14 Drawings (1, 3, 4, 10, 11, 14, 15 July 2001) 430x 22cm speculum

 

ISHADOH, Hiroshi (Id) Naha, Okinawa, Japan

19 Drawings (1, 2, 6, 7, 8, 9+, 10+, 11, 12, 13, 15 July 2001)

340, 400x 31cm speculum/420x 25cm speculum+

 

ISHIBASHI, Tsutomu (Is) Sagamihara, Kanagawa, Japan

7 Colour Images (26, 27, 28 June; 1; 3, 8, 10 July 2001) 31cm f/6.4 spec, Fujichrome 400F

 

KUMAMORI, Teruaki (Km) Sakai, Osaka, Japan

5 CCD Colour Images (2, 3, 10, 13 July 2001)

20cm Dall Kirkham with a Sony PC-5 / 60cm Cassegarain with a Sony TRV-900

 

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

10 Sets of CCD Images (3, 7, 10, 13 July 2001) 20cm SCT with a Starlight Xpress MX5

 

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

82 Drawings (1*~4*, 7*, 8 ~10, 11, 12~15 July 2001)

400x 20cm refra* / 420, 530x 25cm spec/ 400x 31cm speculum chez ISHADOH

 

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

7 Sets of CCD Images (8, 9, 11, 15 July 2001) f/40 36cm Cass with an Astrovid 2000 video camera

 

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

15 Sets of CCD Images (1~4, 7, 9, 10 July 2001) f/50 25cm speculum equipped with an ST-5C

 

MURAKAMI, Masami (Mk) Fujisawa, Kanagawa, Japan

33 Drawings (1~5, 8~11, 13, 15 July 2001) 320, 400x 20cm speculum

 

NAKAJIMA, Takashi (Nj) Fukui, Japan

35 Drawings (2, 3, 4, 7, 9, 14, 15 July 2001) 400x 20cm refractor*

 

NARITA, Hiroshi (Nr) Kawasaki, Kanagawa, Japan

15 Drawings (2~5, 8, 9, 10, 13 July 2001) 320,400x 20cm refractor

 

NISHITA, Akinori (Ns) Fukui, Japan

1 CCD Colour Image (4 July 2001) f/190 20cm refr*equipped with an Apogge AP7p

 

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

11 Sets of CCD Images (3, 5, 6, 7, 9, 13# July 2001)

f/36,44 41cm Meade SCT/ f/39 41cm Newtonian# equipped with a Lynxx PC

 

PARKER, Timothy J (TPk) CA, USA

1 Set of CCD Images (1 July 2001) 31cm Cass with a 3 CCD Cam

 

PEACH, Damian A (DPc) King's Lynn, Norfolk, UK

1 Set of CCD Images (2 July 2001) f/21 31cm Meade SCT with an ST-5C

1 Colour Drawing (3 July 2001) 405x 31cm Meade SCT

 

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

1 Drawing (15 July 2001) 240x 10cm refractor

 

SCHULZ, Robert (RSz) Wien, Osterreich

2 Sets of CCD Images (4&, 14 July 2001)

30cm Clark refraktor& /20cm Meade SCT with Webcam Philips

 

TAN, Wei-Leong (WTn) Singapore

29 Sets of CCD Images (1, 2, 6, 8, 9, 10, 12~15 July 2001)

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

 

TEICHERT, Grard (GTc) Hattstatt, France

1 Drawing (3 July 2001) 330, 310x 28cm Schmidt-Cassegrain

 

TSUNEMACHI, Hitomi (Ts) Yokohama, Japan

8 Drawings (1, 14 July 2001) 360x 12.5cm Fluolite refractor

 

VALIMBERTI, Maurice (MVl) Viewbank, Victoria, Australia

12 CCD Colour Images (4, 9, 13 July 2001) f/80 15cm refra with a TC245 based camera

 

WAKUGAWA, Tetsuo (Wk) Kochinda, Okinawa, Japan

4 CCD Colour Images (1 July 2001) 40cm speculum equipped with a Sony VX-1000

 

$ Richmond Astronomical Society Ragland Observatory

Sakai City Observatory

* Fukui City Observatory

 

Development of the Yellow Cloud :
1 July~3 July (188Ls) :
  As has been noted the observers of the CMO Okinawa were enjoying the fine skies already from 21 June, though the observers in the mainland were still suffering from the rainy season. However on 1 July, several observers including ASADA (As), HIKI (Hk), MORITA (Mo), MURAKAMI (Mk), TSUNEMACHI (Ts), and the present writer (Mn) were endowed with a lull and were able to observe the surface. At Fukui, Mn started from 20:30 JST (11:30GMT at ω=189W) and noticed that the whole surface was covered already by the yellow cloud, and there was still a broad vivid streak of dust cloud along Phthontis-Electris. At ω=199W, though Propontis I was sighted, there was witnessed an effect of a violent disturbance inside and near Elysium and it was apparent that the dark patch in theria was quite deformed. Strangely, there came down a dark segment inside Elysium. WAKAGAWA (Wk)'s images at ω=190W~206W, As's at ω=198W~224W, Mo's at ω=204W~243W and HIGA (Hg)'s Video tape from ω=195W to ω=268W all show these new aspects. ISHADOH (Id) started from ω=213W. Syrtis Mj appeared as expected, and Id observed until ω=260W (16:20 GMT). The deformed shape of the theria dark patch was also checked by Ts at ω=230W. TAN (WTn) at Singapore produced images at ω=243W~266W. Syrtis Mj just remains dark only at the northern part and the eastern part of S Sabus looks to have been affected.

  On 2 July (188Ls), we (Nj and Mn) started from 10:50 GMT (at ω=161W) at Fukui. Clouds floated, but when the planet was near at the meridian, we had a nice and long break in the clouds under a good seeing. We observed that a further disturbance had occurred in the area of Elysium: though Propontis I was weaker, the shadowy streak inside Elysium and the theria dark patch made some differences than the day before. There was seen a bright small disturbance to the south of the dark patch at theria . Mn's observations were made at ω=212W and 222W. Km's image at ω=211W also shows strangely that from Phlegra (that is dark) to theria a shadowy area prevails across Elysium. As's images made at ω=188W~230W comprise these features. Hg's Tape also shows this from ω=186W to ω=195W. Though the dark markings, some being deformed because of dust, were seen through, it wasapparent visually that the whole surface (except for the circumpolar regions) had been affected by the vast yellow cloud. The surface looked like a bright yellow glove, the faint markings being scattered in perspective up to the limbs. The bright yellow surface, looking pretty glossy, was attractive, and Nj and the present writer (both experienced the great yellow clouds in 1956, 1971 and 1973) assented that we had never seen such a beautiful surface completely/globulously covered by the bright yellow cloud. At the same time, we concluded that the event was never local and already it reached a new stage: It was apparent it will never easily subside again so that it must be global. The cloud was not so thick yet, but we could easily conclude that since its power had made the cloud to rapidly expand down to the northern hemisphere, the cloud, though yet thin, should also have already expanded into another hemisphere. How one can believe the present limb of the disk should just be the end of the vivid yellow cloud that presents? We so wrote a notice that night that the yellow cloud was already so global that any observer in a different hemisphere should be on the alert. The quiet invasion of the thin yellow cloud should be watched in terms of the delicate tint of yellow, not by another standard to judge whether the dark markings should become fainter. The frequent use of the IR range will not help to detect a faint flow of the yellow cloud. The airborne dust should first be checked before an arrival of any burst of dust disturbance.
  On 3 July (189Ls), we started from ω=164W at Fukui: The dust streak at Phthontis looked quite active, and the following branch was bright again at the place where the cloud on 29 June crossed M Cimmerium: It was notable on 3 July that the western part of M Cimmerium was suddenly darkened largely. The Elysium area was also active. The yellow cloud looked to become gradually thicker. MORITA (Mo)'s work from 1 July to 4 July is excellent and precious: He made sets of images at the same ω angles (this is the very method recommended by the CMO): The images show how the dust cloud was active from day to day for example affecting the markings differently. Note that this series is a very sequel to AKUTSU's images on 30 June (cited in #247 at p3048). KUMAMORI (
Km) has the images at ω=188W on 2 July and following 3 July.

 

4 July (189Ls):
  On the day there was a new movement to the east: At Fukui, we started from 10:50 GMT (at ω=152W), and observed until ω=182W that an area in Ddalia to the east of M Sirenum was sharply bright suggesting there had been a burst of dust. VALIMBERTI (MVl) in Australia worked on the day and made excellent images from earlier: The burst was first caught at 9:14 GMT(ω=129W) just after the CM. More interestingly this image shows another smaller resonant burst just to the north of Solis L. The colour images of MVl do not show the expanding yellow cloud, but since we shared the observation times, the morning side must have been yellow hazed and hence the uniformity of the surfaces suggests the yellow cloud had already reached at least the longitude of Solis L. At the following area, the western part of M Cimmerium was further darkened as shown on Mo's images as well as on NISHITA's image at ω=225W.

5 and 6 July (191Ls):
  GRAFTON (EGf)'s images on 5 July at ω=058W show two tiny dust disturbances near Solis L, which must be reproductions of the bright dust spot MVl caught on 4 July. Don PARKER (DPk)'s images on the day were at ω=033W, and do not show the area yet, while they show the yellow dust must have reached already as we judge from the abnormality of the area of Auror S. DPk employed the LRGB method; we suppose he made up for the lost contrast.
  On 6 July (191Ls), the dust germs gave a great change: DPk's Red images at ω=048W and 060W show two bright streaks; one from upper Thaumasia down to Auror S and the other from Claritas down to the NE direction. These images were sent with a quick note (cited in #247 LtE) and at the same time he wrote a message to the present writer (cited this issue). We were of the opinion that an earlier arrival of the yellow dust ingredients brought about the bursts.
  We were watching the planet 8 to 10 hours behind from America.
Id made an important observation on 7 July that Olympus Mons appeared as a dark spot at ω=170W. This implies the activity of the dust cloud was in a new stage: The depth of the cloud increased to the extent that just the summit was uncovered while the outskirts were all thickly buried. After that the summit (as well as those of Tharsis Montes) was observed in contrast as a brownish spot from morning to evening. We so rewound HIGA (Hg)'s Videotape and noticed it was already spotted on 6 July (191Ls) but not earlier than 4 July, and so we concluded the new stage was completed on 5 or 6 July. This corresponds timely to the burst near Solis L.

   

7 and 8 July (192Ls):

DPk's drawing on 8 July
  On 7 July (191Ls),
EGf shot at ω=020W, and DPk at ω=026W~031W: the preceding streak looks to have been widened. On the same day, MOORE (DMr) caught the two streak near the centre at ω=043W~068W: The aspect is quite reminiscent of the streaks of the 1973 dust cloud seen on 16 October a few days after the outbreak. The aspect must be related with the topography of the area and the altitude of the dust cloud stratum. On 8 July, the present writer (Mn) moved to Naha to watch the planet and made every-day-observations since then for a month.

9 July~15 July (196Ls):
  DPk's drawings on 9 July
  On 9 July (192Ls), Don PARKER (DPk) in Florida observed at ω=354W and reported that S Meridiani diminished. Two hours later MOORE (DMr) in Arizona confirmed the phenomenon at ω=023W/028W. We otherwise heard on 9 July from Sam WHITBY (
SWb) in Virginia that at 2h GMT Sinus Sabus and Sinus Meridiani were unrecognizable though the seeing was good. Almost all of M Erythrum was buried, but its eastern end and the dark band in Noachis was recognized. However on 11 July (193Ls), DMr wisely shot from the same angle and proved that the Noachis part had become fainter. The remaining isolated patch at the east end of M Erythrum was caught a little earlier by EGf in Texas at ω=343W. On 15 July (196Ls), DMr's images at ω=340W show that another strange new band runs from the remaining patch at M Erythrum down to the eastern part of S Sabus crossing Deucalionis R just like a pseudo Sabus . On 13 July (195Ls), DPk made a set of good images at ω=292W~302W where a lot of markings are shown to be fainter or deformed. Depressiones Hellespontic however is going to show up.

  On 9 July (192Ls) DPk thus shot at ω=354W, DBt in Texas at ω=020W, DMr at ω=028W, and then came the excellent images by MVl in Melbourne at ω=084W/090W. At Naha, Okinawa, ISHADOH (Id) and Mn used a 25cm Newtonian and observed together from ω=110W to ω=183W and near them HIGA (Hg) videotaped from ω=130W to ω=178W. During the Japan time, Mk observed at ω=139W, and Mo shot at ω=154W, and as well TAN (WTn) in Singapore produced images at ω=164W~170W. Thus we may say we covered continuously a half sphere. On MOORE (DMr)'s images M Acidalium is near the CM and the western Erythrum fades and on MVl's, M Acidalium is in the evening and the faded Erythrum prevails while Ascrus Mons is coming. In Japan Mk saw the isolated Olympus Mons near the CM and Mo shot it, and in Okinawa it gradually sank as Propontis I made a figure. It may be possible to chase the rise and fall of the nph as well as the dust complex at the southern hemisphere.

  On 13 July (195Ls) also MVl made a good series of images from ω=040W to 095W nearly every 10 degrees, and Mn at Naha made observations eight times every 10 degrees from ω=082W to 150W, and Hg videotaped from ω=108W to ω=142W. Mk also observed at ω=091W, 101W, 111W, Km at ω=107W, Id at ω=130W, 145W, and WTn in Singapore observed at ω=115W~127W. The pair of Ascrus and Olympus Montes were watched amusingly from ω=100W to ω=150W. Arsia Mons was also visible in a brownish tint and to the south of it there was a strange dark patch which must have once appeared in 1973, maybe the east end of Valhalla so named in 1988. AKUTSU (Ak) made an excellent images of the place on 10 July at ω=135W. On the day (10 July), Mo also made a good series of RGB and IR images from ω=140W to ω=160W.

 

  Steps of the Yellow Cloud :


  In the case of the southern summer dust cloud, the easterly plays usually a main role to make the dust procession to the west. It however appears that the expansion of the present yellow cloud, aroused in early spring, was not caused by the easterly. Instead we consider that by an unknown reason or reasons a faint existence of airborne dust gave rise to a strong local disturbance and this may supply further airborne dust to bring about other several resonances. Such sharp disturbances as seen on 28 June in Libya, on 1 July near Elysium, on 4 July at Ddalia, and those on 5 and 6 near Solis L as well as the unknown source for the obscuration of S Meridiani should all be resonances caused by the preceding expansion of a faint yellow cloud. Such a rapid expansion to the northern hemisphere seen on 1 July cannot be assumed without an earlier arrival of the thin dust caused by the stable disturbance seen near M Cimmerium and Libya on 29 June. We have never witnessed a rapid motion of any bright core to invade some remote areas this time. The bright disturbance might be resonances, but they looked as if independent each other. On 1 July we saw a violent disturbance near Elysium, but before that we noticed that the lower sphere had already been covered well by the yellow cloud. It was not so deep since the markings were all shot through the IR light and also visually checked by the eyes. But it was very apparent the surface was full of airborne dust. So if the depth of the cloud is shallow and if one only refers to the monitor or to the IR images one may not be aware of the existence of the precursory yellow cloud. Some presence of the dark markings on the images does not deny the existence of a vast stirring of the dust. The aspects on the images made by planetary experts for example by PEACH (
DPc) on 2 and 3 July at ω=334W and by CIDADO (ACd) on 4/5 and 6 July cannot be said normal when the angular diameter kept larger than 20 arcsecs. The yellow cloud went to be thick in depth and around 5 and 6 July to the extent that only the summits of the Montes appeared always as singular spots. The question whether the markings are visible or not is a matter of degree, and the expansion of yellow cloud should first be checked by the colour not by the fading of the markings at an earlier stage. We don't consider that any of the present day ccd images are made rich to realise the deep colour of the yellow cloud.

  Polar Regions :
  We wanted to describe about the activity of the nph especially seen at the later part of the present period as well as the apparently rapid recession of the spc, but we postpone it and come back to the review later in a 2001 Note.


T

he next issue shall review the observations during a fortnight period from 16 July (196Ls) to 31 July 2001 (205Ls). We hope every CCD image 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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