96/97 report 001

1996/97 Mars Observation Reports

-- #002 -- 16 Sept. - 15 Oct. 1996


This is the second report of this apparition and treats the period from 16 Sept to 15 Oct, while some earlier observations are included. The north polar cap (npc) has been quite evident and the central latitude rose from 16°N to 21°N. The apparent diameter was however just 4.6" to 5.1" arc (this apparition it will reach 14.2" arc at most on 20 March 1997). The phase angle was 29° to 33°during the present period.

After the preceding edition we received the observations as follows:

HIKI, Toshiaki  (Hk)  Minowa, Nagano, Japan
4 Drawings (27 Sept; 5, 12* Oct) 360X 16cm spec / 340, 400× 20cm refr*
ISHADOH, Hiroshi (Id) Naha,Japan
1 Drawing (2 Oct) 530× 31cm speculum
MINAMI, Masatsugu (Mn) Fukui, Japan
25 Drawings (18, 21, 24, 27 Sept; 1, 5, 11, 12 Oct) 340, 400× 20cm refr*
MORITA, Yukio (Mo) Hatsuka-ichi, Japan
8 B&W Photos (3, 4, 10, 14, 15, 18, 22, 26 Sept) f/100 25cm spec TP2415
MURAKAMI, Masami (Mk) Fujisawa, Japan
4 Drawings (11, 12 Oct) 340, 400× 20cm refractor*
NAKAJIMA, Takashi (Nj) Fukui, Japan
10 Drawings (21, 27 Sept; 5, 12 Oct) 340, 400× 20cm refractor*
NIECHOY, Detlev (DNc) Gottingen, Deutschland
3 Drawings (19, 25, 26 Aug 1996) 225, 229, 330× 20cm
SCHMUDE, Richard W, Jr (RSc) GA, USA
1 Drawing (12 Oct) 380× 51cm speculum
WARELL, Johan (JWr) Uppsala, Sweden
4 Drawings (1 Aug; 17, 25 Sept; 3 Oct) 250,430× 36cm refr/ 400, 330× 16cm refr
* Fukui City Observatory
The 18th day of September was the day when HST was planned to shoot the red planet as announced urgently by Jim BELL one week before, and especially HST was to be in conjunction with the area near Japan: Our active members were thus alerted by MURAKAMI (#179 p1907), and Hk, Id, Mk, Mn, Mo, Nr as well as Ak stood by. As far as we were informed, MORITA(Mo) and the present writer (Mn) were successful in catching the red planet in good time.
HST seemed to started to observe Mars from 18:26GMT, and WFPC2 worked from 20:01 to 20:51GMT. At 20:25GMT the surface of LCM=165°W faced to us. MORITA (Mo) took pictures by TP from 20:07 to 20:22GMT (Mo~006), while the present writer (Mn) observed, as already reported in #179, four times including the time at LCM=165°W. We could watch the planet upto 21:10GMT (LCM=175°W) though quite twilight. The apparent diameter was only 4.6" arc, and this was just like a ceremony for us: The photos by Mo could not even the npc nor the possible markings though the R photo at 20:22 (LCM=164°W) shows a clear image. To the naked eye, the bright npc was well visible, and Tharsis was whitish light near the evening terminator. As already informed, the HST camera seemed to reveal a dust cloud to the north of Propontis I, but it was impossible to catch it within such a small image: Rather the surrounding of the npc looked very shadowy near the evening terminator and quite shadowy up to Propontis I on the morning side. The npc must be new since the season was 011°Ls.
Don PARKER's excellent CCD images (47kb) on the day at LCM=017°W shows a larger hood overflowing the npc to invade M Acidalium.

Our past data show that in the case of 1994, it was when the apparent diameter recovered 7.4" arc that we could discern first Propontis I by the naked eye (in our case with a 20cm telescope on 10 Nov 1994 at LCM=180°W) as a dark stain isolated from the dark fringe (CMO #151 p1494), and so at least a diameter of 8" arc will be needed to find something along the dark fringe. In 1994, ISHADOH (Id) observed thus a light area to the north of Propontis I on 14 Nov (017°Ls) at LCM=169°W, 183°W, on 16 Nov (018°Ls) at LCM=162°W, on 17 Nov (019°Ls) at LCM=157°W and so on (CMO #151 p1798/99) which may be a thing similar to that observed by HST this year. WHITBY (SWh) also observed on 3 Nov 1994 (012°Ls) that the north polar region was bright bifurcated at the morning side (CMO #151 p1494/95) and this suggests another possibility. As other candidates, we can pick out a light belt which constantly followed Tempe along the dark fringe as observed when the app diameter was 13.1" arc on 4 Dec 1992 (006°Ls) by Id, Nj Mn and others (CMO #126 p1149). The CCD images by PARKER (DPk) on 21 Dec 1992 (014°Ls) show however a white cloud to the north of Propontis I.

During this one month, the region from around LCM=180°W eastwards to Syrtis Mj was observed from Japan. HIKI (Hk) observed M Acidalium near the evening terminator on 27 Sept at LCM=074°W, but could not discern the npc from the nph, while at the same moment the npc was checked at Fukui (016°Ls). ISHADOH observed on 2 Oct at LCM=038°W where M Acidalium was dark near the CM together with Nilokeras, and Ganges was faintly seen because of good seeing. Argyre was light a the southern limb. Hk saw S Meridiani near the CM on 5 Oct at LCM=358°W; S Margaritifer looked darker however. On 11, 12 Oct, Mk and Hk made their observations on the occasion of the Workshop at Fukui: Seeing was poor on 11 Oct, but on 12 Oct the condition improved and both caught Syrtis Mj near the CM and the dark Utopia at the evening side as well as the bright npc. Hk was an anchor on 12 Oct and saw upto the morning S Sabaeus at daybreak (when LCM=299°W).

The observations by Mn during the period was extraordinary; being caused by the following situation: On the very day of 18 Sept when HST was in conjunction with our telescopes, before Mn met the red planet at dawn, he watched Saturn at midnight and happened to detect a white oval in EZ together with a following dark stain as well as a wavy dark belt stretching to the morning side. Occasionally he made the CMT timing of the dark stain which followed the white shell, and hence he was forced since then to go to the observatory every three or four days to make the CMT timing to reduce its retardation against System I. He thus stayed several nights at the observatory to incidentally watch our planet Mars. On Saturday, he worked together with NAKAJIMA (Nj) who has however been very busy in his professional work. On 21 Sept (after observing Saturn), Mn watched Mars when it was low and Nj observed the higher Mars in the twilight. On 24 Sept, Mn watched from LCM=081°W to LCM=110°W: The npc was bounded by a shadowy broad band. The southern limb was also light. The image on the night showed a clear orange~yellowish tinge. On 27 Sept, we started from LCM=054°W, and saw M Acidalium dark at the evening side which Nj also enjoyed. The npc whitish bright, and bounded by a dark fringe. Chryse was misty near at the evening terminator. The southern limb, maybe Argyre, was light. The dark markings on the southern hemisphere were visible, but Solis L was not isolated. On 1 Oct: seeing was poor while Argyre looked light. On 5 Oct (019°Ls), seeing improved near dawn, and Nj and Mn observed alternatively: S Sab us was clearly seen upto the eastern end, and we also could watch as M Acidalium came into sight. The point lies in the following: there was no thick white hood which covered the morning M Acidalium to Tempe, and the npc part was independently evident. In 1994, this configuration was observed in Japan at 007°Ls (Oct 1994) and at 025°Ls (Nov 1994); the polar mist being present in the former case. On 11 Oct seeing for Mars was poor (while Saturn was watched under better condition). On 12 Oct (022°Ls), the night extra of the Workshop, the sky became fine just before the red planet shined well, and Hk, Mk, Nj and Mn watched by turns a better Mars. By coincidence, Syrtis Mj was near the CM and Hellas appeared to be truly roundish bright.

The work by MORITA(Mo) is really a labour, and each sheet is composed of a lot of TP photo~prints (more than one hundred). However, the apparent diameter was too small to produce the details. Comparing with the success of the CCD images by DPk on 18 Sept, we hope Mo hastens to change his method (he already purchased a CCD camera).

The method of observation of NIECHOY Detlev (DNc) looks peculiar to us (while maybe common in Germany): He took several drawings within a few minutes by changing the filters. The three consists thus of 12 drawings. For example on 25 Aug he took 5 drawings from 2:57GMT to 3:21GMT, and two were by use of B (Schott BG28) and O(Schott OG550), while other three might be without filter but the images shown look different and impossible to identify the markings. Any usual Int drawing needs twenty minutes observations. Observations made in a different day should be sketched in a different sheet.

SCHMUDE, Richard W, Jr (RSc)'s observation on 12 Oct was made at around 11:00GMT. He didn't describe LCM, and looks to have no interest in the identification of the dark markings.

WARELL, Johan (JWr) started from 1 Aug at LCM=338°W when app.dia.=4.2": Syrtis Mj at the evening side was caught. The nph was quite large. After more than one month on 17 Sept (010°Ls) at 3:30GMT (LCM=288°W), Syrtis Mj was caught again near the CM. The npc looked evident. He observed then on 25 Sept at LCM=208°W and on 3 Oct (018°Ls) at LCM=127°W: Our member Mk already saw the later images on the Internet and felt that the npc was described smaller, as to which the present writer agrees. This is so even if JWr at present uses appropriately a reduced drawing disk (much smaller than 5cm).