96/97 report 009

1996/97 Mars Observation Reports -- #009 --

OAA MARS SECTION - Fortnight Report

Martian Surfaces in the First Half of March 1997

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

(Extracted from CMO #187 p2027, 25 March 1997)

Mars observation is at its height. The apparent diameter was 13.3" on 1 Mar, and 14.1", nearly maximal, on 15 Mar. The northern hemisphere of Mars welcomed the summer solstice (090°Ls) on 13 Mar: During the period the season advanced from 085°Ls to 091°Ls. The central latitude remained around 23°N. Opposition was ahead, and hence the phase angle was minimal (never vanishes usually: the present case the defect of illumination will pass from east end through the southern limb to the west limb). In Japan at opposition the planet is observable from 10: 30GMT to 19:30GMT, and hence the morning observations in California will readily be relayed to the evening observations in Japan, and we can also share our early-morning Mars with the European observers (if they start in the early-evening).

We received with thanks the following observations contributed to the CMO:

     AKUTSU, Tomio (Ak)  Karasuyama, Tochigi, Japan
          12 CCD Images  (3, 4, 5, 10 Mar)   f/66× 32cm speculum, Lynxx PC

     CAVE, Thomas R (TCv)  CA, USA
          14 Drawings  (13, 21 Jan; 1, 6, 8, 10, 12, 16, 19, 22, 23 Feb; 9, 11, 12 Mar) 
                                230, 400, 550, 660× 32cm speculum

     DIJON, Jean (DJn)  Champagnier, France
           5 CCD Images (2, 3, 6 Mar)  31cm speculum  hand made CCD camra with Kodak KAF400

     FALSARELLA, Nelson (NFl)  Brasil
          14 Drawings  (15, 18, 20, 22, 23, 24, 25, 26, 27, 28 Feb; 1, 2, 3, 7 Mar) 260× 20cm spec

     GROSS, Horst  (HGr)   Hagen, Deutschland
           4 Drawings  (7, 8, 9, 10 Mar)     250× 25cm Schiefspiegler

     HEATH, Alan W  (AHt)  Nottingham, UK
           2 Drawings  (11, 12 Mar)  190, 320× 30cm speculum

     HIKI, Toshiaki (Hk)  Minowa, Nagano, Japan
          2 Drawings  (5 Mar)  340× 16cm speculum 

     HIGA, Yasunobu  (Hg)  Naha, Japan 
           1 FD Image (28 Jan)  25cm spec, Sony DV Camera VX1000 processed by Photoshop
          46 Video Images  (19, 22, 26 Feb; 5, 7, 9, 10, 12, 14 Mar) 25cm spec, Sony VX1000

     ISHADOH, Hiroshi  (Id) Naha, Japan
          28 Drawings  (4, 5, 6, 9, 10, 11, 13 Mar)  530× 31cm speculum

     IWASAKI, Tohru  (Iw) Morodomi, Saga, Japan
          17 Drawings  (1, 3, 4, 5, 8, 9 Mar)  400× 21cm speculum

     MELILLO, Frank J  (FMl)  NY, USA
           1 Drawing  (1 Mar)    310× 20cm Schmidt-Cassegrain
           3 B&W Photos (8, 11, 13 Mar) 20cm Schmi-Cass AO-2 unit TP2415 Wr#47 & Wr#21
     MINAMI, Masatsugu  (Mn)  Fukui / Otsu+, Japan
          63 Drawings  (3, 4, 5, 7, 9, 11, 12+ Mar) 400, 480, 630× 20cm refra* /420× 20cm spec+
     MURAKAMI, Masami  (Mk)  Fujisawa, Japan
          17 Drawings  (4, 5, 7, 11, 12 Mar)    370× 15cm speculum

     NAKAJIMA, Takashi (Nj)  Fukui, Japan
          25 Drawings  (3, 4, 7, 8, 9, 11 Mar)    400× 20cm refractor*

     NAKANO, Yuhkichi (Nn)   Oh-ita, Japan
           6 Drawings  (3, 4, 6 Mar)    420× 20cm speculum
     NARITA, Hiroshi (Nr)   Kawasaki, Japan
          24 Drawings  (19, 20, 23, 24, 28 Feb; 4, 5, 6, 7, 8, 12, 14 Mar)  400× 20cm refractor

     NIKOLAI, Andre (ANk)  Berlin, Deutschland
           4 Drawings  (28 Feb; 4, 9, 10 Mar)   330× 10cm refractor

     NISHITA, Noriaki (Ns)  Fukui, Japan
           5 CCD Images  (5 Feb)   20cm refractor– ,  Mutoh CV-04

     OHBA, Yoshio (Oh)  Yamagata, Japan
           3 Drawings  (27 Feb; 3, 5 Mar)  270× 15 cm spec, 210, 270, 320× 20cm spec

     SCHMUDE, Richard W, Jr  (RSc)  GA, USA
           5 Drawings  (16; 23 Feb; 2, 8, 12 Mar)
               250× 9cm refr; 570× 51cm --> 13cm spec, 300× 15cm spec, 380× 25cm spec

     SIEGEL, Elisabeth  (ESg)  Malling, Danmark
           2 Drawings  (4, 8 Mar)  270× 20cm Schmidt-Cassegrain

     TEICHERT, Gerard  (GTc)  Hattstatt, France
           6 Drawings  (6, ~11 Mar)  280, 310,330,350× 28cm Schmidt-Cassegrain

     TROIANI, Daniel M  (DTr)   IL, USA
           5 Drawings  (4$, 6$ Feb; 7, 11, 12 Mar)  680× 45cm spec$, 520× 44cm spec
                                                   * Fukui City Observatory
                                                   $ Winter Star Party, Lower Florida Keys

As the observations obtained earlier, we received with thanks the following: Some of DNc and KHb were sent by courtesy of W MEYER (WFS).

     HEUBNER, Kurt  (KHb)  Berlin, Deutschland
           4 Drawings  (1, 2 Feb)    190× 15cm refr, 250× 20cm refr
     NIECHOY, Detlev  (DNc)  Goettingen, Deutschland
          12 Drawings (1 Sept; 11,20 Oct; 22 Dec; 2,14,16 Jan; 1,23 Feb) 225, 290× 20cm SC

     SUDWISCHER, Harry  (HSw)  NY, USA
           1 CCD Image  (16 Feb)    13cm refractor  VAV 505E Video Camera

The Newsletter concerning the HST conjunction from 6:30 to 18:30GMT on 10 Mar, received 6 Mar, was readily forwarded by M MURAKAMI, E-mail Secretary of the OAA Mars Section, to the domestic active observers by use of e-mail and FAX. Unfortunately the weather was nearly poor at the main island, but AKUTSU (Ak) made an R CCD image at 16:58GMT, and at OKINAWA where they enjoyed a clear sky, ISHADOH observed 8 times from 13:20 to 18:10GMT every forty minutes, and HIGA (Hg) took Video images by use of 3CCD Camera 7 times from 16:00 to 20:00GMT (each continues for 5 minutes every 40 minutes). These images are all excellent and may well be compared with the HST images which will be soon uploaded.


CAVE (TCv) sent us his drawings in an old BAA format (the column for apparent diameter missing), and we hope he will use Ls instead of the heliocentric longitude of the Sun. On 1 Feb (072°Ls) at ω= 116°W, TCv detected a light spot in the northern hemisphere but not identified. On 6 Feb at ω=071°W he saw Hyperboreus L. On 23 Feb at ω=263°W, he drew the classical Elysium light but not as Elysium Mons. On 8 Mar he seemed to meet good seeing, but the drawings on 8 and 9 Mar appears us mysterious (Alba is missing if ω=143°W). On 12 Mar ω= 098°W, Olympus Mons was shown in the morning side.

FALSARELLA (NFl)'s drawings: On 18 Feb (080°Ls) NFl detected Elysium Mons at about ω=250 ° W, maybe one of first observations of the Very Active Elysium Mons white cloud. NFl sent us by air-mail, in addition to the 26 Feb observation which was sent us by e-mail and recorded in #186, several others which show the dark band running between Olympus Mons and Tharsis ridges taken on 27 Feb at ω=160 ° W, 28 Feb at ω=148 ° W, 1 Mar at ω=140 ° W, 2 Mar at ω=130 ° W and on 3 Mar at ω=115 ° W. NFl however did not separate Ascraeus Mons.

MELILLO (FMl) took a drawing on 1 Mar at ω=209 ° W, while Elysium was at the morning side and looked rather pale. Images on TP hypered were on 8 Mar at ω=133 ° W, 11 Mar at ω=110 ° W and 13Mar at ω= 073 ° W with a 75 seconds exposure through Wr#47: On 8 Mar (088 ° Ls) Olympus Mons was like a cotton ball in the evening, while the area bright at the morning limb 13 Mar.

SCHMUDE (RSc) observed the active Elysium Mons on 23 Feb at ω= 270 ° W. He experienced a fire broke from the next flat (fortunately just some smoke damage) on 2 Mar about 3 hours after the observation at 4: 30GMT. On 12 Mar at ω=080 ° W, a thick evening haze was observed.

SUDWISCHER (HSw) obtained his first CCD image on 16 Feb at ω=020 ° W which shows clearly S Sabaeus, M Acidalium et al, but it seems to have been somewhat ill-processed because the shape of the markings looks queer. His newer images (on 16 Mar) have arrived but will be reviewed in the next issue.

TROIANI (DTr) enjoyed an excellent seeing (10/10) at the Winter Party at Florida and made detailed and good - configurative drawings on 4 Feb at ω= 044 ° W and on 6 Mar at ω=067 ° W. On 7 Mar at ω=119 ° W, he described the morning Olympus Mons and others while Alba seemed to be absent. On 11 Mar at ω=075 ° W, he observed by use of a light blue filter the so-called "equatorial band cloud". We cannot however understand why it is called "Cloud".


0) During the period we were able to see from Japan the range from the Syrtis Mj area to Elysium pass the CM. S Sabaeus and Syrtis Mj were observed well. The seeing condition was good in general, and especially at Okinawa ISHADOH (id) and HIGA (Hg) made good observations.

1) The npc and its fine dark fringe : As stated in the preceding issue at CMO #186 p2018, the north polar cap (npc) is nearly at its minimum, and a fine dark fringe of the npc has been very evident (as far as the Japanese observation was possible) from around 19 Feb (080°Ls) ever since it appeared accompanied with Hyperboreus L. The dark fringe was however not uniform but complexed in shape, and very dark at some length while quite faint at some range. This fact was paid attention by Id, Mn and NAKAJIMA (Nj), while IWASAKI (Iw) didn't made any notes about the fringe though he mentioned much of the npc itself. As Id observed 4, 5 and 6 Mar (086°Ls - 087°Ls), the fringe extended from Hyperboreus L towards the east was dark and rather broad upto ω=300°W - 260°W, while it suddenly began to fade down (cf also #186). Mn's observations on 3, 4 and 5 Mar (086°Ls - 087°Ls) also produced similar results through the Int light, but the faded part became quite darker since around 9 Mar (088°Ls), and hence Rima Borealis became very evident through the Int light. On the day Mn observed that the whole fringe was thus visible from ω=281°W to ω=320°W. The same result was obtained also on 11 Mar. Id described the fringe to be dark and long at ω=302°W on 10 Mar. The fringe is surely seen in the CCD Red images on 24 Feb (083°Ls) by Don PARKER uploaded in the MarsWatch Web site, but the images on the same MarsWatch Web by Mark SCHMIDT taken on the same day (24 Feb) are more suggestive: His images were produced every one hour, and at ω=214°W, the dark fringe is absent, and at ω= 231°W it is on its half-way, while at ω=244°W, the dark fringe now fully appears. This may show the dark fringe was asymmetrical on those days to the effect that the Rima Borealis at least at the west end was fainter through the white light.

2) Olympia : Olympia was for example caught by Id at ω=280°W on 6 Mar, but it was rather weak. Mn on 5 Mar also saw that the west-half of the dark fringe was very dark and broad (not smooth) while the the other side was so faded that it was as if the npc including Olympia gradually faded away to the eastward. However after 9 Mar, Rima Borealis turned out to be cleared dark, and Olympia was more clearly separated. On the other hand, from 11 Mar (089°Ls), the region around ω=200°W came into sight from Japan: From this angle a white Olympia was evident near the CM and overlay at the outskirts of Rima Borealis. This was somewhat contradictory to the DOLLFUS result cited in Fig 1 at p1984 of #183 (where there was spotted a dark segment of the fringe at ω=200°W), and the east end of Olympia was located farther eastward from ω=200°W.
At the same time, the angle ω=200°W called our attention because, as was reported in #185 p2003, we (Mn and Nj) observed a fourth in the morning side of the npc was depressed in a yellow-ocher colour on 10 Feb (076°Ls) at around ω=200°W: The part proved this time more depressed. This fact can also be interpreted reasonably as follows: At around 075°Ls, the npc was large enough to include the area of Olympia, and Rima Borealis was also faint through Int light, while at the same time the following west part of Olympia and the follower was on the way of rapidly melting away: The rapidly thawing region must have been made tonally changed to have a tint of yellow ocher as it often had been witnessed in the case of the south polar cap. Nearly at 090°Ls, the follower melted away and the core of Olympia and Rima Borealis stood clearly.
[Some seasonal gap must have been buried by the observations in Europe, but according to a recent BAA Report No 6 of R McKIM, received 14 Mar, any UK observation was negative in detecting the delicate ingredient of the region from the important angle around ω=200°W.]
As another good example showing the situation at around 075°Ls, we can again refer to the work by QUARRA (GQr) and others on 9 Feb as cited in #186 p2021: The colour versions show that the extension of Olympia to the westward was largely faded though Rima Borealis and its extension were not so evident (seen however in the IR images). It is just difficult to read a tonal difference over there because the pixels are relatively large.

3) Chasma Boreale
Id's drawing 06Mar1997 As reported in the preceding issue, Id checked Chasma Boreale for example on 25 Feb. At Fukui, Mn observed a glimpse of Chasma Boreale as a dark inlet from the rear side at ω=273°W on 3 Mar. Id detected it again on 6 Mar at ω=300°W and on 11 Mar at ω= 302°W and so on. It may be difficult however to identify the direction of the rift if observed when Chasma is nearly along the latitude line.

4) Elysium Mons : From the beginning of March Elysium proved to be bright at the evening limb side, but it was since 9 Mar (088°Ls) in Japan that Elysium Mons inside the disk appeared to be covered by a white cloud. It was apparent that Elysium Mons was already Very Active in the sense of SMITH & SMITH. Elysium Mons (213°W) was observed to become brighter in the afternoon: On 9 Mar we at Fukui observed the brightness after ω= 240°W, and even at ω=272°W it was seen inside the disk as a compact bright spot. At ω=291°W it came to the terminator and shined brighter than the npc through a Green filter (phase angle ι=7°). On 10 Mar, Id also described Elysium Mons as a rather small bright area at ω=241°W, while at ω=270°W and 280°W as a sharp bright spot. He also similarly observed it on 11 Mar. On 11 Mar Elysium Mons was discerned from ω=230°W. On the other hand, Mk distinguished Elysium Mons from the evening haze at ω=260°W on 12 Mar. The activity of Elysium Mons was low in a previous turn (see #185 p2002 for the period at around 075°Ls), but FALSARELLA (NFl)'s observation on 18 Feb (080°Ls) at ω =250°W shows Elysium Mons as a bright spot as well as SCHMUDE (RSc)'s on 23 Feb (082°Ls) at ω =270°W, and also Don PARKER's B light CCD on 24 Feb (083°Ls) at ω =260°W shows well the bright Elysium Mons, and hence the VA state of the area must have begun around 080°Ls.

5) Morning M Acidalium : M Acidalium is known to be haunted often by a morning mist thickly in some season, but at this season it seems to be rather free from any thick mist even in the early morning (a small phase angle may be another reason). On 5 Mar we met a good seeing condition at Fukui, and Mn could see a beautiful picture of M Acidalium obliquely lying totally inside the disk at ω =304°W (as well as the early-morning Oxia P). Id also saw the total shape of M Acidalium 4 Mar at ω =303°W and 6 Mar at ω =310°W. We cannot say that it is completely free from the mist because Thymiamata was still morning hazed even through the eye. In fact Ak's B-light CCD images on 3 Mar at ω =315°W and on 4 Mar at ω =311°W, 326°W show clearly the morning light mist which hides the M Acidalium area. HIGA (Hg)'s Video images on 10 Mar also show a covering by mist over the morning M Acidalium (see below).

6) Evening haze and morning mist : Several observers checked the evening haze which covered the afternoon to evening Syrtis Mj as well as the morning mist over Chryse. Typically Iw's and Mk's observations on 1 Mar (085°Ls) at ω =341°W and on 4 Mar (086°Ls) at ω = 342°W respectively show both. In the B-light CCD by Ak taken 4 Mar at ω =342°W shows a long haze from the morning Chryse to the evening terminator. At Fukui 11 Mar (089°Ls) at ω =310°W, an evening haze was watched to extend over Syrtis Mj up to Aeria. Aeria was whitish light also in the morning; for example on 9 Mar (088°Ls) at ω = 240°W and 250°W (while Id on 10 Mar at ω =250°W commented that it was not so bright). Aeria appeared to be light having a core near the CM (eg 3 Mar ω =280°W - ω =310°W et al, especially if O56 was used).

7) Casius : The west end of Utopia was a darker and broad band. It is well known that its southern top is an apex and the tip curves westward, but it is particularly fascinating to be able to see the aspect by our own eye. Id from 4 Mar every time produced this interesting aspect. If this is easily checked, it implies one can see other minor markings such as N Alcyonius as a simple spot and Boreosyrtis as a complexed bird-shaped marking and so on. Umbra must originally be implied a dusky area, but Id saw a light spot inside 5 Mar as well as 10 and 11 Mar.

8) Miscellanea : Hyperboreus L was a key of seeing: Iw detected it 3 Mar at ω =334°W etc, and Mk on 4 Mar at ω =342°W and 5 Mar at ω =348°W separated from M Acidalium. Hellas was bright in the afternoon and in the evening, while weak in the morning. Hellas must have been morning hazed when Eridania was lighter as in the case 11 Mar (089°Ls) ω = 240°W.
HIGA (Hg)'s moving Colour images by a 3CCD video - camera is good especially at producing the morning mist and evening haze (if one wants to say, also the equatorial hazy band) in addition to some detailed description of dark markings. These digital images can be transmitted to a computer to yield processed still images on monitor in future. Hg worked on 9, 10 and 12 Mar for 4 hours to take 7 or 8 times of the planet surface every forty minutes.
NISHITA (Ns) first tried this apparition to take pictures by a CCD camera at the Fukui Observatory, and was successful. The R-image on 5 Mar at ω = 300°W is excellent: Though still raw it shows several minor markings such as N Alcyonius, Boreosyrtis, Hyperboreus L as well as the fine dark fringe of the npc.


DIJON (JDj)'s CCD images all show similar configurations in some details: From 2 Mar at ω =067°W to 8 Mar at ω =039°W, all images show a light area in Tempe. This area must be coincident with the one observed by Mk on 23 Feb (CMO #186 p2020). The ground must be sunlit mixed with a thin haze.

GROSS (HGr) started from March: 8 Mar (088°Ls) at ω =356°W, HGr drew the morning mist thick. He was aware of the presence of Hyperboreus L on 10 Mar at ω =345°W.

HEATH (AHt) started his observation on 1 Mar at ω =114°W. On 10/11 Mar at ω =027°W, AHt detected a bright (as bright as the npc) limb patch near Candor by use of Wr#47. He also observed on 11/12 Mar at ω = 006°W & 016°W. On 12/13 Mar at ω =355°W, S Sabaeus was already showed intensity 6, while M Acidalium 5.5. Chryse was light at the morning limb.

HEUBNER (KHb)'s drawings show the area of M Acidalium though he does not describe the ω . Observing Notes are unreadable because of bad copying.

NIECHOY (DNc) also does not describe the ω , and furthermore the image must be mirrored, and hence we cannot identify any markings. The npc looks detailed, but not identifiable.

NIKOLAI (ANk) saw the Xanthe-Candor evening haze on 28 Feb (086°Ls) at ω =133°W, while Olympus Mons was not detected. This must be because of a limit of the resolution power of his refractor, but it is equally possible that the Very Active white cloud as observed at around 075°Ls in Japan (see #185 p2002) was passing. On 10 Mar at ω = 339°W, ANk drew the evening Syrtis Mj with a preceding haze.

SIEGEL (ESg) observed on 4 Mar at ω =056°W and on 8 Mar at ω = 017°W. Both show the morning limb bright through filters. The latter detected a cream coloured light area near Candor. Evening terminator was covered by a white-bluish haze.

TEICHERT (GTc) seems to have met fine weather, as well as other European observers, from 6 Mar to 11 Mar: GTc depicted the Chryse haze in the afternoon on 6, 7 and 8 Mar. His npc is too small to balance the description of the northern part of M Acidalium.


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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