96/97 report 017

1996/97 Mars Observation Reports -- # 017--


- Monthly Report published in CMO #195 (25 September 1997) -

Martian Sufaces Observed from 16 August to 15 September 1997

- - - by Masatsugu MINAMI, Director of the OAA Mars Section ---

The planet Mars has to be caught in the twilight; if not it rapidly goes down from our country. Mars is now in Lib and the apparent declination of the planet read -18° in mid-September. The present report deals with the period from 16 August to 15 September 1997: The apparent diameter was 6.0" on 15 Aug while it went down to 5.5" on 15 Sept. The season proceeded from 165°Ls to 181°Ls, the vernal equinox of the northern hemisphere. The central latitude was 22°N down to 15°N. The phase angle decreased also from 39°to 36°.

We thank the followimg observers who are still chasing the red planet:

  ISHADOH, Hiroshi (Id) Naha, Okinawa, Japan
     7 Drawings  (30 Aug; 1, 7, 9, 10, 12 Spt)  530× 31cm speculum

  IWASAKI, Tohru (Iw) Kita-Kyushu, Japan
   11 Drawings  (21, 22, 23, 25, 26, 30, 31 Aug; 1, 2, 8, 12 Spt)  400× 21cm speculum

  MINAMI, Masatsugu  (Mn)  Fukui, Japan
   34 Drawings (16, 17, 18, 21, 24, 26, 27, 30 Aug; 2, 10, 11, 12 Spt) 480× 20cm refractor*

  MURAKAMI, Masami  (Mk)   Fujisawa, Kanagawa, Japan
    4 Drawings  (17, 24# Aug; 1, 11 Spt)    315× 10cm refr# /370× 15cm speculum

  NAKAJIMA, Takashi  (Nj)  Fukui, Japan
   10 Drawings  (16, 27, 28 Aug; 10, 11 Spt)    480× 20cm refractor*
                                      * Fukui City Observatory

We also acknowledge receipt of the reports of the following Deutsch observers:
(We are indebted to Wolfgang MEYER for CHs, and to Andre NIKOLAI for HSt):

    HAASE, J Carsten (CHs)   Berlin, Deutschland
            1 Drawings   (5 Mar) 250× 15cm refraktor an der WFS

    STARZYNSKI, Hermut (HSt) Berlin, Deutschland
           11 Drawings   (21, 24, 24, 26 Apr; 1, 10, 13, 15, 19, 24, 30 May) 
               200× 28cm Schmidt-Cassegrain

From our lands

We could observe the area around ω=140°W in mid August, and pursued eastwards and watched around the region ω=250°W at the end of the period. The weather was different to different districts. There are still two hours from the beginning of observations at Fujisawa and Fukui to the end of the observations at Okinawa. We paid much attention to the north polar region (npr).

16 Aug, at Fukui Mn started from ω=133°W (9:40GMT) and Nj from ω= 138°W. A trace of Solis L was seen at the p limb and the southern (s) limb light. Tharsis became definitely light as time went by. The npr just dull whitish.

17 Aug, Mn from ω=123°W: A trace of Nilokeras was seen, and Xanthe light near the p limb. The s limb light. Mk at Fujisawa observed at ω= 128°W and pointed out the lightness of the p and the s limb.

18 Aug, Mn from ω=113°W: Solis L was visible, and a tail of Nilokeras to Mareotis L ran to SW direction to the north of the light Xanthe-Tharsis area. The npc was definitely whitish.

21 Aug, Mn from ω=086°W(9:50GMT): Solis L was evident dark. M Acidalium was just near the p limb sending a dark band to Mareotis L. The npr dull whitish. At ω=096°W, a light area appeared at the s limb. Iw at Kokura made at ω=101°W (10:50GMT) and noticeed Solis L. The npr is dull light but he didn't see any brightness of the npc. The p limb light.

22 Aug, Iw from ω=091°W: The area of Solis L shadowy. The npc is obscure.

23 Aug, Iw from ω=081°W: The light npr looked somewhat larger. M Acidalium remained. Tempe not light.

24 Aug, Mk introduced the planet at 9:20GMT (ω=050°W) and observed the shadowy M Acidalium. The npr blue-whitish. At Fukui, Mn from ω= 052°W (9:30GMT) -- : S Meridiani and S Margaritifer were visible, and the s limb to Noachis was light. M Acidalium dark. Tempe not light. The npr whitish light. At ω=062°W, M Erythraeum and Aurorae S looked quite dark. The p limb (Thymiamata) light. The morning Tharsis misty.

25 Aug, Iw from ω=062°W (10:50GMT): The area between the p limb and M Acidalium was whitish bright. The s limb (Argyre) whitish light. The npr dull light. The morning Tharsis also dull light.

26 Aug, The sky was poor. Mn at ω=047°W and Iw at ω=052°W: The npr whitish and the p limb light.

27 Aug, at Fukui Mn from ω=023°W (9:30GMT), and Nj from ω=028°W -- : Seeing very poor. The p limb largely light (thru Y48), and Argyre evident (thru O56). A morning mist near the npr. M Acidalium seen.

28 Aug, Nj fromω=018°W -- : S Meridiani dark and Argyre light. The npr whitish.

30 Aug, Mn from ω=354°W (9:30GMT) -- : The npc white, and at the s limb Argyre lighter and Noachis less light. The p limb light. Chryse morning misty. Iw at ω=013°W(10:50GMT): Argyre was lighter than the npr. Morning mist near the npr. S Meridiani definite while M Acidalium still obscure. Id observed at ω=021°W (11:20GMT) while no dark markings identified. The p limb light. The npc showed a definite area.
[ In Fukui it was no more possible to observe Mars at 11:20GMT those days. On the day Mn watched the planet Jupiter at 11:30 when the GRS was passing the CM together with the two very bright white ovals which were seen qutite symmetrically to the south of the GRS. Twelve days after they became already unsymmetrical. ]

31 Aug, Iw at ω=003°W: The s limb looked lighter than the npr.

01 Sept, Mk observed at ω=332°W (9:30GMT): Syrtis Mj shadowy near the p limb. Hellas a bit seen. The light npr slightly larger. Id at ω=351°W (10:40GMT): S Meridiani evident, not so dark however. Syrtis Mj dark and proceeding Libya light at the p limb. Chryse morning misty. The npc not so evident, but he judged it was well light. Iw at ω=354°W(10:50GMT): Transparency good enough to show the light npc. The s-limb light was declined to the morning side (Argyre). Syrtis Mj still visible.

02 Sept, Mn at ω=322°W (9:20GMT) -- : The afternoon Syrtis Mj was very clear while S Sabaeus was duller though S Meridiani definite. Hellas a bit light near the p limb. At ω=332°W, Hellas weaker than Libya. Iw at ω=344°W: The npr whitish light. Hellas remained. S Meridiani weak in the morning.
[ On the evening of 2 Sept, it was 30°C at the Fukui Observatory. Since then the weather was poor at Fujisawa (Mk), Fukui (Nj) and Otsu (Mn), and we could not observe the moments when Hellas was near the noon. Scarcely some observations on 7 & 8 Sept by Id and Iw complemented. ]

07 Sept, Id at ω=293°W: Syrtis Mj was near the CM while Hellas was still in the morning (The phase angle ι = 37°), slightly off-white to M Serpentis. The season was 177°Ls, and Hellas' brightness at a final stage? (Cf #134 p1251.) The p limb to Libya off-whitish light. N Alcyonius could not caught. Utopia vague. The npr blue-whitish.

08 Sept, Iw at ω=285°W: The white Hellas was lighter than the npr. Utopia unknown.

09 Sept, Id at ω=276°W: Hellas looked light but dull. The p-limb light at the NH was like a light belt.

10 Sept, at Fukui Mn started from ω=244°W (9:20GMT) and Nj from ω= 249°W -- : Hellas was not yet, but the s limb, maybe Eridania, was quite bright, looked off-white compared with the npr. Utopia is definite but fainter than M Cimmerium. The morning side of the npr was misty. The p limb light. Not observable after 10:40GMT at Fukui. Id could observe however at ω=266°W (10:50GMT) (the apparent diameter was 5.5", and so he decreased his drawing circle to 2.5cm diameter). Syrtis Mj was near the morning terminator, while the s limb bright.

11 Sept, at Fukui Mn at ω=234°W (9:20GMT), 244°W and Nj at ω= 249°W: The s limb was bright as before, looked rather whitish. M Cimmerium quite dark. Utopia well shadowy and its morning neighbour was misty. The p limb light. Mk observed at ω=239°W (9:40GMT). He also saw the bright canopy at the s limb at the morning side. The npr light, and the p limb-light was seen particularly at the NH.

12 Sept, Mn at ω=224°W (9:20GMT) -- : The s limb light but duller. The npc small roundish white. Seen a morning mist preceding Syrtis Mj. Iw at ω=236°W (10:10GMT): a white patch at the s limb. Elysium unknown. Id at ω=247°W and at ω=256°W (11:30GMT): Seeing was good before a Typhoon, and he saw Hesperia clearly. The afternoon M Cimmerium was dark. The s limb, Eridania, was off-white. The morning mist preceding Syrtis Mj thicker. Elysium was not seen. The npc vague but definitely light. Now reached 180°Ls.

Observations by the Mars Global Surveyor

Observations by the Mars Global Surveyor on 20 Aug (167°Ls): The Surveyor took pictures on 20 Aug on the way to a Martian orbit, and three images were uploaded (see Click CMO - CMO Clicks below for more detail):

The first one shows a gibbous image of Mars whose sub-spacecraft point was (82°W, 24°N). It was by use of a narrow angle camera, and in the range of R to IR. The contrast is not so good but the details around Aurorae S are very superb and perhaps the remnant of the 27 June dust is still seen at Valles Marineris. The npc shows Chasma Boreale. Near the terminator Ascraeus Mons is seen as a small dark spot. The description of Ganges is near ours by naked eyes.
Next one at (217°W, 24°N) shows a shadowy area of Cerberus -Styx in the same way as we saw. The light part of Elysium is west declined. The morning shadow by Elysium Mons is very evident. Olympia is clearly visible.
Last at (307°W, 24°N) where Syrtis Mj is impressive, and N Alcyonius is an isolated stain. Utopia is described in detail. Hellas is caught by the last one, and looked covered by a whitish matter but we need a blue light image. The npc is always seen well (since the tilt= 24°N) but looks dull in the morning. Notable is that the Korolev crater is filled with perpetual ice (cf CMO #189 p2076 as well as #177 p1872).

We- Further- Received

Carsten HAASE (CHs)'s observation was made on 3 Mar at ω=045°W, where M Acidalium is vaguely drawn.

STARZYNSKI (HSt) observed as follows:
21 Apr at ω=333°W, Hellas light and the npc was drawn small (appeared too small to HSt always). A haze near at the morning terminator.
24 Apr at ω=314°W, Syrtis Mj (die grosse Syrte) is the darkest (das dunkelste Objekt) and Utopia weaker. Around the npc, there is, so asserted, a light region (frost laid?).
25 Apr at ω= 282°W (blue), Hellas is like a polar cap (wie eine Polkappe). A light area near the morning terminator.
26 Apr at ω=273°W (blue), the npc was dull and a lighter spot inside Hellas. The Aetheria dark patch visible.
01 May at ω=221°W (blue & orange), Olympia must have been seen. Elysium largely light?
10 May at ω=141°W (blue), there is a shadowy area near the centre: Mareotis L?
13 May at ω=110°W (blue), there seems an EBC, but the dark markings were not well fixed.
15 May at ω=082°W, M Acidalium was near the p limb. Tempe looks light.
19 May at ω=049°W Int•blue), M Acidalium bends near the CM and Chryse inside an EBC?
24 May at ω=002°W(blue et al), the positioning of S Meridiani is wrong.
30 May at ω=306°W (orange et al), again Syrtis Mj. Hellas was still bright as a polar cap. The drawing of the surrounding the npc is not realistic. Data about Ls and others are missing.

Yukio MORITA (Mo) has been too busy to make the observation documents at present, but we hear that he started his CCD image taking from 27 Dec 1996 and ended on 21 July 1997, and during the period he took about 1200 images of Mars secured in about 130 numbers of FD. Three images were shown to us as examples: one was taken on 24 Mar at ω=116°W, another on 11 Apr at ω=333°W; both being excellent, and the rest was the one taken on the final 21 July where the apparent diameter=6.7 arcsecs while M Acidalium is clearly shown. We hope we will be able to report about his work soon.

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

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