2001 Mars Observation Reports -- #17--

OAA MARS SECTION

CMO Mars Observations


in the Second Half of October and the First Half of November 2001
from 16 October (253°Ls) to 15 November 2001 (273°Ls)
based on the article published in CMO #253 (25 November 2001)

 


Masatsugu MINAMI, Director of the OAA Mars Section



 

T

HE planet Mars is going away, decreasing its angular diameter, while the meridional altitude of Mars is increasing seen from our hemisphere, and hence we are now able to watch it for a longer time than in August: This time we review the observations made during the one-month period from

16 October (253°Ls) to 15 November 2001 (273°Ls).

  The apparent angular diameter went down from 9.7" to 8.1", while the apparent declination went up from - 24° 10' to - 18° 30': The planet is now nearly as high up in the evening sky as we experienced in Naha, Okinawa this summer. The central latitude moved from 11°S to 19°S. The phase angle went down from 46° to 44°. The south summer solistice was attained on 11 November.
  Temperature inside the dome at Fukui was around 20°C in mid-October, while it recorded 10°C or lower in mid-November (the lowest temperature on the morning of the marvelous Leonids showers was 5.6°C in Fukui while 17.4°C in Naha. Otherwise 6.3°C in Hiroshima, 3.6°C in Nara (where KUMAMORI was on the expedition) and 7.7°C in Tokyo). On 4 November, the summit of Mt Hakusan (dormant volcano) was witnessed from hear to have been covered with a white mantle by the first snow. HIKI also communicated that the Japanese Alps in Nagano turned white.

 

T

HE observations submitted to us are as follows: Since the planet can be most favourably observable at twilight, this is convenient to some observers, but very inconvenient to others if they work in a remote place. Unfortunately MORITA's equator is still out of order.

 

     AKUTSU, Tomio (Ak) Tochigi, Japan

           10 Sets of CCD Images (20, 27 October; 11 November 2001)

 f/70 32cm speculum with a Teleris 2

 

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

            7 Colour Drawings (16, 21# , 24 October; 3# November 2001)

                     300x 20cm speculum / 510, 330x 26cm speculum#

 

     DOMBROWSKI, Philip L (PDb)   Glastonbury, CT, USA

               3 CCD Red Images (18, 30 October; 11 November 2001)

  f/30 30cm  SCT with an Astrovid

 

     ISHADOH, Hiroshi (Id)  Naha, Okinawa, Japan

            21 Drawings (18, 22, 24, 25, 26, 27 October; 2, 3, 5, 10, 12 November 2001)

                                    400, 340x 31cm speculum

 

     KUMAMORI, Teruaki (Km)   Sakai, Osaka, Japan

            13 CCD Colour Images (20, 24, 25, 27, 31 October; 7, 10 November 2001)

                                    60cm Cassegrain $ with a Sony TRV-900

 

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

             7 CCD Images (19, 28, 30 October; 6, 10 November 2001)

                               20cm SCT with a Starlight Xpress MX5

 

     MINAMI, Masatsugu (Mn)  Fukui, Japan

           72 Drawings (18 ~ 20, 26, 27, 29 ~ 31 October; 2, 4, 7, 10, 11, 14, 15 November 2001)

                                     480, 400x 20cm refractor*

 

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

           2 Sets of CCD Images (3, 11 November 2001)

f/35 36cm Cassegrain with an Astrovid

 

     MURAKAMI, Masami (Mk)   Fujisawa, Kanagawa, Japan

            15 Drawings (19, 20, 23, 31 October; 4, 11, 12 November 2001)

 320x 20cm speculum

 

     NAKAJIMA, Takashi (Nj)   Fukui, Japan

           15 Drawings (18, 23, 29 October; 4, 10, 11 November 2001) 480, 400x 20cm refractor*

 

     NARITA, Hiroshi  (Nr)   Kawasaki, Kanagawa, Japan

           21 Drawings (19, 20, 24 ~ 27, 31 October; 1, 4, 11, 14 November 2001)

 400x 20cm refractor

 

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

            10 Sets of CCD Images (24 October; 8, 11/12 November 2001)

                              f/44 41cm Newtonian equipped with a Lynxx PC

 

     TEICHERT, Gérard  (GTc) Hattstatt, France

            5 Drawings (30 October; 1, 3, 10, 11 November 2001)    330, 310×28cm SCT

 

     TSUNEMACHI, Hitomi (Ts)   Yokohama, Japan

          43 Drawings (19, 20, 24, 26, 27, 31 October; 4, 7, 11, 12, 14 November 2001) 

                                             360x 12.5cm Fluorite refractor

 

     VALIMBERTI, Maurice (MVl)  Viewbank, Victoria, Australia

             4 Sets of CCD Images (27 September; 3, 14 November 2001)

                              f/92 15cm refractor with a TC245 based camera

 

                                                                $ Sakai City Observatory

                                                               * Fukui City Observatory

General :

 

  During the period, the south polar cap (spc) was visible distinct. Our estimation of the spc's recession rate this season from June is under way and will be dealt with soon in a coming CMO Note. ISHADOH (Id) depicted the spc clearly often inside the disk. The viability of the present yellow cloud was unprecedented while the air-laden part looks to have almost dissipated, and the activity of the water vapour has been reset.

 

18 October (255°Ls) ~ 23 October (258°Ls) :


  This period the area from M Sirenum to M Cimmerium faced to us in Japan (also in Asia and Oceania). Hesperia was faintly seen cutting M Cimmerium from the eastern part of M Tyrrhenum. The west end of M Sirenum looked to have extended up to the longitude=180°W, while the Symplegades Insulæ largely occupied. The morning mist or fog was often seen, indicating the activity of water vapour. The R image of DOMBROWSKI (
PDb) at CT was made at LCM=044°W on 18 October (255°Ls) that suggests the well darkened marking and a clear spc. In Japan,on 18 October (255°Ls) at LCM=229°W, the present writer (Mn) observed a dull whitish morning fog near the terminator may be on Hellas.
  His observation on 19 October (day 118 since the onset of the dust storm, 255°Ls) at LCM=190°W suspected a pinkish aspect of the northern deserts and suggested that the airborne dust nearly subsided from this area (though this does not imply at all the yellow cloud totally disappeared: The disk image is still in a tint of bright yellow suggesting that the thin dust floats in the air). At LCM=199°W, the morning Ausonia also looked misted. The central latitude=11°S, The apparent diameter=9.6", The phase angle=46° on the day.
  On 20 October (256°Ls) at LCM=180°W, MURAKAMI (
Mk) recorded that in addition to the morning mist or fog the light continent belt of Electris and Eridania looked rather whitish. KUMAMORI (Km)'s images on the day at LCM=180°W and 192°W show Electris and Eridania to make a dull light belt. TSUNEMACHI (Ts) on 20 October noted at LCM=187°W that the northern deserts show a reddish yellow tinge. The area around of the spc was dusky and expanded to M Chronium. AKUTSU (Ak) on the day took IR, RGB and Int images at LCM=188°W.
  On 22 October (257°Ls) at LCM=212°W, ISHADOH (
Id) caught the whole area of M Cimmerium. On 23 October (258°Ls), NAKAJIMA (Nj) suspected a shadowy spot on the afternoon northern area at LCM=170°W, 180°W. Possibly a shadow of the Olympus Mons Summit.

 

24 October (258°Ls) :

 
  Don PARKER (DPk)'s images on the day (The central latitude=13°S, The apparent diameter=9.2", The phase angle=46°) at LCM=023°W, 028°W, 036°W and 040°W are excellent and show lots of things. A few of these are: First they show S Meridiani rather in a normal form, secondly they show the darkened markings from M Erythræum to Margaritifer S and Auroræ S to be spotted with several patches of fallout sedimentary dusts, and thirdly they show the legendary Argenteus Mons. This looks white but is seen clearly in R and G, and so must be a condensate. As to the area of Mons Argenteus we are not sure, and this must be related with Argyre (silver island near Ganges while Chryse is a gold island on the sea of Erythra), but the present whiteness in a triangular form should be said to suit the name Argenteus Mons (white silver mountain, nomenclature by E M ANTONIADI 1924).

  It was originally defined at (the longitude=030°W, the latitude=70°S) while DPk's images show it around at the longitude=040°W. As reported in #252, this white area was also shown on the image by Km made on 26 September (241°Ls) at LCM=058°W. If it is the condensation of the water driven from the outskirts of the maximal spc, it may imply that the activity of water was recovered around from 240°Ls (Day 95) in accordance of a retreat of the dust storm. As noted below, Mons Argenteus was observed frequently in November by VALIMBERTI (MVl) and the Japanese observers. The present writer (Mn) in 1986 observed it on 14 September 1986 (244°Ls) at LCM=055°W, 21 September 1986 (248°Ls) at LCM=023°W and so on, and hence it is considered its season is usual. DPk' Observing Note shows (fourthly) that the R image on 24 October at LCM=023°W depicts a trace of Novus Mons faintly, detached from the bright spc. The season was 258°Ls was reasonable. See CMO #111.
  On 24 October 2001, in Japan
Ts observed at LCM=138°W, 148°W, Km took Video images at LCM=153°W, and Id observed at LCM=173°W, 183°W. Id looked for the trace of Olympus Mons but failed. The eastern tail of M Sirenum was observed to go down northward (to Dædalia-Claritas)

 

25 October (259°Ls) ~ 31 October (263°Ls) :


 
Km took images at LCM=130°W, 141°W on 25 October (259°Ls) showing the darkening of the Dædalia-Claritas area and the latter image show a light slit between it and the foregoing dark patch.
  On 26 October (260°Ls),
Ts observed at LCM=129°W, 139°W, 148°W, 158°W, and checked the dark area at Dædalia-Claritas at LCM=129°W ~ 139°W and also suspected the shadowy area near Arsia Mons. Id on the day observed at LCM=151°W & 161°W and tried to find Olympus Mons, bright or dark, but was not sure. According to the SMITH-SMITH pattern (CMO #134), there should be no activity of the orographic cloud at these season on the summit of Olympus Mons. In 1988, the Martian surface around at 270°Ls showed a round and bright Olympus Mons (not cloud covered), but its apparent diameter read near 24 arc-seconds. Even if any cloud activity be recovered in the afternoon, the phase angle must be too deep at present. Id tried again on the next 27 October (260°Ls), but in vain.
  On the day,
Mn observed at LCM=109°W, 119°W and so on and checked the extraordinary dark patch north-west on the Solis L area. On Km's images at LCM=111°W & 120°W as well as on AKUTSU (Ak)'s images at LCM=134°W on the day, the patch is separated from the Dædalia dark marking. Mn's observations on the day showed that the following Memnonia was lighter than the preceding Thaumasia, while on 29 October (262°Ls) at LCM=119°W, and on 30 October (262°Ls) at LCM=099°W & 109°W, he contrarily observed that the NS light belt at Thaumasia and Ophir following the dark Auroræ S appeared much lighter.
  31 October (263°Ls), the seeing condition was favourable at Fukui, and
Mn observed at LCM=060°W, 070°W, 080°W, 090°W, 099°W, 109°W: At LCM=070°W Mons Argenteus was clearly checked, and the spc was clear definite at 600x. The preceding area of the spc was clearly bounded, while the following morning area was slightly blurred. The area of Auroræ S was quite dark, and the following Thaumasia and Ophir belt was well light. At LCM=080°W, Ophir-Candor looked rather reddish. The north polar hood (nph) was weak on the day. The dark patch on the Solis L area seemed to have become larger. It was quite inside at LCM=099°W. The morning terminator side was misty or covered by a fog.

  Km also enjoyed a better seeing on the day and his images at LCM=074°W & 083°W show well the white Argenteus Mons: Ophir is also shown up as a bright specific area. The dark patch near the Solis L area is off north-westwards from the original Solis L. The images this time well show the perimeter shape of the spc. Km's image at LCM=074°W is a composite stacked of 199 Video images.
  Frank MELILLO (
FMl) announced a dust disturbance near Hellas and Noachis that was said brighter than the spc based upon his R images on 28 October (261°Ls) at LCM=309°W. This was not confirmative by the later observations at Australia (MVl) and Japan, but the R image by DOMBROWSKI (PDb) on 30 October (262°Ls) at LCM=295°W shows a large bright Hellas while the spc is seen. MOORE (DMr) secured the same angle on 3 November, as cited below.


2 November (263°Ls) ~ 6 November (266°Ls) :


 
Mn detected Mons Argenteus in a triangular form on 2 November (263°Ls) at LCM=056°W where the following area of Auroræ S was light. Id also observed the area around Ophir to be light at LCM=082°W: Ganges was visible.
  On 3 November (265°Ls), VALIMBERTI (
MVl) from Australia took pictures at LCM=059°W, 072°W; The area of Argenteus Mons is light but off-white. The image at LCM=072°W is nicely comparable with his former image at LCM=075°W made on 27 September (241°Ls) at LCM=075°W (sorry; we missed to refer to it in the preceding issue): The area of Auroræ S has gained much darkness within one month with the sediment slightly more blown, but the light belt from Thaumasia to Ophir-Candor remains similar. The dark patch near the Solis L area is more evident now. We should also note that the 27 Sept images by MVl prove the appearance of Mons Argenteus (as early as Km at the same Ls). On 3 November (265°Ls), Id also caught a light area at Mons Argenteus at LCM=063°W.
  4 November (265°Ls),
Nj and Mn observed from LCM=019°W to 070°W, and saw Mons Argenteus from LCM=035°W to 058°W. Ts detected also it at LCM=031°W & 041°W on the day. Id seemed to check it on 5 November (266°Ls) at LCM=048°W. Id judged that the darkness of main markings had picked up. He saw the round and clear spc inside the disk.
  MOORE (
DMr) near the Diamondbacks home took images on 3 November (265°Ls) at LCM=295°W where the Hellas complex appears large and bright (but not known if it is extraordinary or not). The spc is evident, and the morning Syrtis Mj is shown in R and IR (while vague in B). On 6 November (266°Ls), MELILLO (FMl) took the R images at LCM=215°W & 221°W.

 

7 November (267°Ls) ~ 10 November (169°Ls) :


  Mn observed 7 November (267°Ls) from LCM=349°W to 037°W: First Hellas was light on the afternoon side, while there was no particular dust disturbance in Noachis. The spc was clearly evident and it was suspected a faint Novus Mons. The area of the eastern base of S Sabæus and M Serpentis looked fat and dark, and S Meridiani was seen rather skinny. The central latitude=17°S. The dark band on Noachis obliquely from M Serpentis ran to M Erythræum, and the south of the band looked slightly light. At LCM=017°W, the following morning area was misted or foggy.
 
Km made images near at LCM=002°W where S Meridiani is evident and a rather light band along the dark band in Noachis is well shown. Ts observed at LCM=021°W when the clouds broke: The spc was clear fringed, and saw the dark markings had been more darkened than before. The nph was weak but its boundary was rather definite, and saw the desert to the south to have a reddish yellow tinge.

  On 8 November (269°Ls), DPk obtained images at LCM=213°W, 219°W & 222°W where M Cimmerium is totally shot: M Cimmerium and the eastern part of M Tyrrhenum had gained rather their original configurations and the junction is pushed from the bright Eridania.
  On 10 November (269°Ls),
Nj and Mn observed at LCM=320°W ~ 349°W: the inside of Hellas was not uniform, and the area of M Serpentis and S Sabæus was quite dark, and S Meridiani came into sight at LCM=335°W (Nj) and LCM=339°W (Mn). Hellespontus was not uniform. A morning mist or fog from the southern Noachis to the terminator. On the day, Km shot at LCM=324°W (before sunset), and at 333°W. The former shows a lighter area of a dustdrift at the western edge of Hellas. Hellas is lighter than the northern deserts, but the brighter area of Hellas is not as large as Hellas on the images by FMl on 28 October. Id observed at LCM=006°W, 016°W where he saw vaguely the morning mist. The spc was obvious, but Id thought it looked slightly off-white. The area of M Serpentis was quite dark to him also. On 10 November (269°Ls), FMl made the R images at LCM=177°W & LCM=182°W.

 

11 November (270°Ls) ~ 15 November (172°Ls) :


  On 11 November (270°Ls) at 00:58 GMT,
DMr shot the planet at LCM=214°W where M Cimmerium is shown and Hesperia is suspected in IR. The southern continents make a light EW belt and Eridania is a bright patch. These images at the angle, as well as the images by DPk on 8 November at LCM=213°W, add information to the series of those in July made by MORITA shown in #248 p3071. On the day, in Japan AKUTSU (Ak) started early from 5:54 GMT (14:54 JST; much before sunset) and he secured eight IR images from LCM=286°W to LCM=342°W. Hellas is compactly light and rotates with Syrtis Mj. At LCM=302°W, M Hadriacum is complete. The colour composites were made at LCM=304°W, 328°W and 340°W: The last set is excellent with a good B image. The spc is white definite, the area of M Serpentis and the east S Sabæus is shot dark. The Noachis dark band from M Serpentis to M Erythræum is accompanied by a faint lighter area to the south of it. On the day, Mn started from 16h JST at LCM=303°W, and first observed that M Tyrrhenum was separated by a linear sediment of dust from Syrtis Mj. The southern part of M Hadriacum was detected. Hellas showed a dustdrift at the northern edge area. Nj joined from LCM=317°W: The spc was very evident and Æria was less light than Hellas. At LCM=349°W (Mn), the southern morning terminator was misted. Ts observed at LCM=312°W, 322°W, 332°W, 342°W, 351°W: Hellas was compactly bright, and it was whitish yellow. M Serpentis was dark and at LCM=351°W she came to catch S Meridiani. A light patch was seen at the morning side at southern high. The nph was brighter near the p limb. On the day Mk also observed at LCM=310°W, 320°W, 330°W, 340°W, 349°W: At LCM=310°W, the area of M Serpentis appeared darker than Syrtis Mj. At LCM=330°W, S Sabæus gained darkness. At LCM=340°W, the Libya cloud began to invade the area of Syrtis Mj. At the GMT midnight from 11 to 12 November, DPk shot at LCM=171°W, 192°W, 195°W where the junction area of M Sirenum and M Cimmerium is clearly shot. The light continents involving Electris bound from the south. Olympus Mons is no more shot.
  On 12 November (270°W),
Ts observed from LCM=303°W to 351°W: At LCM=303°W & 313°W, Syrtis Mj was definite pinched at both sides by the light deserts that were yellowish. At LCM=322°W, there was witnessed a series of light patches adjacent to the Noachis dark oblique band. S Sabæus looked fat as well as S Serpentis. At LCM=342°W, Hellas was near the limb, and showed a yellowish white tinge. Id observed the day at LCM=340°W, 349°W; the seeing and transparency were too poor to detect the afternoon Syrtis Mj or to detect the afternoon cloud.
  On 14 November (272°Ls),
Ts observed at LCM=283°W ~ 303°W, where M Tyrrhenum was dark and its north cloud at the p limb was bright especially at LCM=293°W. Hellas looked light but not so large. On the day, MVl obtained good images at LCM=308°W, where Hellas is compactly bright, but quite off-white compared with the white spc. At Fukui, the seeing was poor but Mn observed at LCM=290°W ~ 339°W where the spc and Hellas was in good contrast in colour. At LCM=320°W, the afternoon cloud (at Libya) was thicker: it was light through O56. The evening the temperature inside the dome went down to 8°C.
  On the final 15 November (272°Ls),
Mn observed from LCM=261°W to 315°W: At LCM=261°W and 271°W, there was witnessed a compact white cloud at the p limb of the southern continents. Hesperia was visible. Hellas in the morning looked covered by the morning fog or mist. Syrtis Mj remained however dim even at LCM=281°W implying it had been under a morning mist. The phase angle=45° so that it was located in a mid-morning way.

 

To Conclude :


  Hellas remained to be as dusty bright as in August and September. Since the density of dark markings around was turning normal, the brightness looked rather striking this period. The brightness of Hellas may however be extraordinary for this season. In 1986, Hellas in this season was cream-coloured but appeared not so bright even on the afternoon side (it was 275°Ls and The central latitude=19°S on 2 November 1986). In 1988, the inside of Hellas was complex and showed light and shade, and even with some bright spots Hellas itself was not bright in general (270°Ls on 10 September 1988), and Ausonia looked more definitely bright. And so Hellas at present should be said to be under the aftereffect of the major dust storm. The SMITH-SMITH pattern says that Hellas is usually free from the white diurnal fog or frost at this season while the situation may change a bit from 300°Ls.
  The water trapped at the peripheral skirts of the maximal
spc already evaporated, but the vapour distribution should not be said to have much shifted to the deep north by the present season. So the fog or mist phenomena should be watched. The area of Solis L looks still extraordinary, but if the dust is not locally triggered to rise up so much, the reduction of the vapour will not occur by the obscuration through scattering in the dust, and then the mist or fog may begin to play the seasonal role. In 1988, we observed at around 285°Ls a very bright and thick ground fog at the morning side when the Solis L area was at dawn (made much from vapour but maybe mixed with airborne dust, cf CMO #108).


We further received :

 

     AKUTSU, Tomio  (Ak)   Tochigi, Japan

            2 Sets of CCD Images (16, 29 September 2001)  f/70 32cm speculum with a Teleris 2

  Ak's images on 16 September (234°Ls) are at LCM=165°W and those on 29 September (242°Ls) are at LCM=039°W. The Ak's yellow colour diminished in the later image.


T

he next issue (#254, 25 December) shall review the observations during a one-month period from 16 November 2001 (273°Ls) to 15 December 2001 (291°Ls).
  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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