16

th Report:

The CMO/OAA Observations made during a fortnight period

 from

1 October 2003 (271°Ls)

to

15 October 2003 (280°Ls)

 


An OAA Mars Section article to be published in CMO #281 (25 October 2003 issue)


 Masatsugu MINAMI, Director of the OAA Mars Section


Japanese version here


H

ere we review the Mars observations during the first half period of October 2003, where the apparent diameter δ decreased from 20.7" to 17.9". Since the maximal angular diameter in the 2001 apparition was 20.8", we should say now the unprecedented opposition of Mars has ended. During the present period, the Martian season proceeded from λ=271°Ls, just after the southern summer solstice, to λ=280°Ls. The previous great Mars in 1988 was closest to the Earth (on 22 September) when λ=277°Ls, and hence it is interesting to be aware that the present season corresponds to the season of the 1988 Mars at opposition. At that time, the central latitude φ was 21°S, and this period φ was from 20°S to 22°S, and so nearly identical. The phase angle ι increased from 26° to 33°.

 

T

he observers and the total observations were decreasing in number: ASADA (As) quitted shooting, and MORITA (Mo) was absent this period because his equator was out of order. AKUTSU (Ak)’s motor drive was also in trouble, and so his observations were vacant from 19 September to 5 October. The observers abroad became also inactive; Ch PELLIER (CPl) observed only two nights, while Don PARKER (DPk) and Johan WARELL (JWr) were active with productive results.

 

AKUTSU, Tomio (Ak)  Tochigi, Japan

            7 Sets of CCD Images (6, 8, 9 October 2003)

                          f/33×32cm spec with a Bitran BJ-41L

    

BARNETT, John H (JBn)  Richmond, VA, USA

            2 Drawings (8, 13$ October 2003)

                   290,360×15cm Mak-Cass & 270,360×18cm refractor$,

                        $ Richmond Astronomical Society Ragland Observatory

    

BEISH, Jeffrey D (JBs)  Lake Placid, FL, USA

            1 Drawing (9 October 2003)  590×41cm F/6.9 speculum

    

BENAVIDES, Rafael (RBn)  Córdova, España

            6 CCD Images (5, 7, 9 October 2003)  24cm SCT with a ToUcam

    

BERRY, Peter (PBr)  Panama City, FL, USA

            3 CCD Images (6, 7, 9 October 2003) 

 f/25,30×23cm SCT with a TRV-900

 

BUDA, Stefan (SBd)  Melbourne, Australia

            1 CCD Image (6 October 2003) 

f/32×25cm Dall-Kirkhams with a ToUcam

    

BUNGE, Robert (RBg)  Bowie, MD, USA

            5 Drawings (2, 7, 8, 10, 14 October 2003)

 249,480×43cm F/7.8 spec

    

CIDADÃO, António José (ACd)  Œiras, Portugal

            3 Sets of CCD Images (6, 10 October 2003)

 25cm SCT with an FLI CM7-1E + AO2

    

COLVILLE, Brian (BCl)  Ontario, Canada

            1 Sets of CCD images (7 October 2003) 

 f/30×30cm SCTwith a ToUcam Pro

    

DOBBINS, Thomas A (TDb)  OH, USA

            4 CCD Images (3, 8, 13, 14 October 2003)

f/28×35cm SCT withToUcam & Wedge prism

    

FRASSATI, Mario (MFr)  Crescentino (VC), Italia

            1 Drawing (6 October 2003)    250×20cm SCT

    

FUMEGA UCHA, Camilo (CFm)  Ourense, España

            1 CCD Image (8 October 2003)  

 f/25×31cm spec with a ToUcam  

     

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

            3 Sets of CCD Images (11, 14, 15 October 2003)

 f/39×35cm SCT with an ST-5C

    

IWASAKI, Tohru (Iw)  KitaKyushu, Fukuoka, Japan

 10 Drawings (2, 4, 9 October 2003) 400×21cm speculum

     

KOWOLLIK, Silvia (SKw)  Stuttgart, Deutchland

            1 CCD Image (2 October 2003)

18cm Starfire Refraktor with a ToUcam Pro

     

KUMAMORI, Teruaki (Km)  Sakai, Osaka, Japan

           11 CCD Images (1, 3#, 8#, 15 October 2003)

                     f/84×20cm Dall-Kirkham &

 f/30×60cm Cass# with a ToUcam

                                         #Sakai City Observatory

    

MASSÓ MILLEIRO, Félix (FMr)  La Corña, Galicia, España

            4 CCD Images (4, 5, 10 October 2003)

15cm F/8 Refr with a Quickcam 3000 Pro

    

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

           5 Red CCD Images (4, 6, 10, 14 October 2003) 

                           m SCT with a Starlight Xpress MX5

    

MINAMI, Masatsugu (Mn)  Fukui, Fukui, Japan

           64 Drawings (2, 3, 4, 6, ~9, 12, 15 October 2003)

                         480, 400×20cm F/12 ED Goto refractor*

                           *Fukui City Observatory, Fukui

    

MURAKAMI, Masami (Mk)  Yokohama, Kanagawa, Japan

7 Drawings (9, 15 October 2003) 320, 400×20cm speculum

    

NAKAJIMA, Takashi (Nj)  Fukui, Fukui, Japan

           13 Drawings (2, 6, 9, 15 October 2003) 

 480, 400×20cm F/12 ED Goto refractor*

                                                    *Fukui City Observatory, Fukui

    

NARITA, Hiroshi (Nr)  Kawasaki, Kanagawa, Japan

           11 Drawings (6, 9, 10, 15 October 2003)  400×20cm refractor

    

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

           24 Sets of CCD Images (4, 7, 9, 10, 13, 14 October 2003)

                f/55, 59×41cm F/6 spec equipped with an ST-9XE or ToUcam

    

PEACH, Damian A (DPc)  Buckinghamshire, England

            5 Sets of CCD Images (10, 13, 14, 15 October 2003) 

                              f/31×28cm SCT with a ToUcam

 

PELLIER, Christophe (CPl)  Bruz, Ille-et-Vilaine, France

            4 Sets of CCD Images (7, 11 October 2003)

                        18cm spec with a modified B&W ToUcam Pro

    

SÁNCHEZ, Jesús R (JSc)  Córdova, España

            3 Sets of CCD Images (8, 12, 14$ October 2003)  

                 f/50×28cm SCT & f/40×25cm spec$ with a ToUcam

    

SHERROD, P Clay (CSr)  Aso Sky Observatory, AR, USA

            2 CCD images (3, 15 October 2003)  

 f/35×41cm SCT with a ToUcam Pro

    

SIEGEL, Elisabeth (ESg)  Malling, Danmark

            5 Drawings (2, 4, 5, 11, 12 October 2003) 

270×20cm F/10 SCT

    

TEICHERT, Gérard (GTc)  Hattstatt, France

            2 Drawings (13, 15 October 2003)    330×28cm SCT

 

VALIMBERTI, Maurice P (MVl)  Melbourne, Australia

            6 CCD Images (3, 6, 10, 13, 14 October 2003)

 f/34×35cm SCT with a ToUcam Pro

 

Van Der VELDEN, Erwin (EVl)  Brisbane, Australia

            2 CCD Images (12, 15 October 2003)

f/31×20cm SCT with a Vesta Pro modified

    

WASIUTA, Mylon E (MWs)  Spotsylvania, VA, USA

            1 CCD Image (8 October 2003)   

 f/30×15cm refr with a ToUcam

    

WARELL, Johan (JWr)  Tcuson, AZ, USA

3 Drawings (2, 12, 14 October 2003)

260, 270×25cm SCT (LX200)

           16 Sets of CCD Images (2, ~6, 9, 12, ~15 October 2003)

                               f/24×25cm SCT with a ToUcam

 

 

This Fortnight, the area from Solis L was well observed from Japan to the region of S Sabæus. In the US, the area of Syrtis Mj and Hellas was mainly watched. The European observers were able to trace from the Syrtis Mj region to M Sirenum’s.

 

The Hole of the Morning Condensate: In ##14 and 15, we took notice of a strange, roundish de-concentration of the morning mist at Amazonis which was first chased by Canon LAU (CLa) on 9 September 2003 (λ=257°Ls): This was still preserved to this period, and checked by several ccd imagers. On 2 Oct (λ=272°Ls), WARELL (JWr) showed it at ω=120°W (refer to the B image). This seemed a very nice moment to chase this phenomenon, but unfortunately JWr’s preceding observation was made 20°W before, and no trace after the ω=120°W shot. The de-concentration was also checked on 6 Oct (λ=276°Ls) by VALIMBERTI (MVl) at ω=123°W, and by AKUTSU (Ak) at ω=141°W: Ak’s case shows it when the Sun was slightly higher, and the shape of the dark area in B should be noticed. His B image at ω=154°W still shows a further diffused shape. Rough estimate by the use of the phase angle (ι=29°) shows that in the case of MVl, the spot at Ω=160°W was 1 hrs 40 minutes after the sunrise, and in Ak’s ω=141°W case the LMT is about 3 hrs after the sunrise. The phenomenon is shown also on Km’s image on 8 Oct (λ=276°Ls) at ω=115°W: The next one at ω=123°W also shows it weakly. On the day, ι was 30°, and so that ω=115°W implies one hour after the sunrise (similar to original CLa’s ω=096°W case). Visually the present writer (Mn) observed on 4 Oct (λ=273°Ls) at ω=136°W, 146°W etc and on 6 Oct (λ=276°Ls) at ω=128°W, that Amazonis showed a reddish or brownish shadowy area among the very thick mist (through a G filter) at the morning side, while it was hard to check its shape. The morning mist was also thickly taken by JWr on 3 Oct (λ=272°Ls) at ω=095°W. Similarly JWr produced several images showing the various interesting morning mists with strange shadows in B on 4 Oct (λ=273°Ls) at ω=074°W, 102°W, and on 5 Oct (λ=274°Ls) at ω=066°W, 088°W etc, but unfortunately his shots are not successive but separated by 20 or 30°W, missing to reveal the internal developments. It should be noted that JWr’s observing site is located quite westward from DPk’s, and so his is located in an important position.

 

  Wine-Coloured Ground. I:  TDb’s image taken on 3 Oct (λ=272°Ls) at ω=041°W shows generally an interesting reddish hue at the dark area preceding Thaumasia Fœlix down to S Meridiani and further eastward until Noachis. It can be thus considered that the vast region is less covered by the airborne dust and condensates now. DPk’s images on 4 Oct (λ=273°Ls) at ω=017°W~077°W also show the wine colour distribution at the dark area preceding Thaumasia though slightly narrowly depicted than TDb’s. They further show a wine coloured de-concentration of mist from Soils L toward its north-west. These are also expected on the images by JWr on the day as noted above.

Visually the wine coloured area was watched generally to the east of the Solis L region (eg by Mn on 9 Oct (λ=276°Ls) at ω=190°W etc). Moving to Oceania, MVl’s images on 13 Oct (λ=279°Ls) at ω=049°W, and on 14 Oct (λ=279°Ls) at ω=050°W show explicitly the same phenomenon. The previously cited images by Km on 15 Oct also show the same colour nuance. At Noachis, the same colour is shown on the image of TDb on 8 Oct (λ=276°Ls) at ω=347°W.

 

  Wine-Coloured Ground II: Similarly, as noted in the previous issue, M Chronium shows deeply a wine coloured hue. Km’s images on 1 Oct (λ=271°Ls) at ω=200°W & 214°W prove it as well as MVl’s on 3 Oct (λ=272°Ls) at ω=163°W, on 6 Oct (λ=274°Ls) at ω=123°W, and on 10 Oct (λ=277°Ls) at ω=132°W etc: These show it runs quite eastwards. Ak’s image cited before made on 6 Oct also prove. The same region shot on PEACH (DPc)’s LRGB images taken later on 14 Oct (λ=279°Ls) at ω=195°W also suggests the same colour. Visually the colour was evident to Mn as dark brown or brownish dark on 4 Oct (λ=273°Ls) at ω=166°W, 180°W, 195°W etc.

 

The Evening Limb: As the phase angle ι has grown larger, the mist looked thicker and complex near the evening limb under low sun illumination. At Fukui it was visually evident on 4 Oct (λ=273°Ls) at ω=195°W through a G filter. On 7 Oct (λ=275°Ls) at ω=109°W it looked wide and whitish, while at ω=128°W the limb side at the southern high latitudes looked off-white: It was so until ω=147°W, but later became whitish. On 8 Oct (λ=276°Ls) at ω=090°W, the evening side was not bright and rather dull, and at ω=099°W ~ ω=119°W it looked mingled with dust. From 12 Oct (λ=278°Ls), the evening limb whiteness was obvious. In Europe, SIEGEL (ESg) recorded that the evening limb was misty bright (using several filters) on 4 Oct (λ=273°Ls) at ω=284°W, 5 Oct (λ=274°Ls) at ω=272°W, and on 12 Oct (λ=278°Ls) at ω=205°W etc. The high latitude limb on 4 Oct was particularly bright.

  Km tried to enhance the whitish mist over the surface from around 8 Oct onwards. It was effective eg on the images taken on 15 Oct (λ=280°Ls) at ω=035°W~104°W. Visually the whitish mist became conspicuous around from 12 Oct (λ=278°Ls), and on 15 Oct the present writer recorded that the white mist prevailed all over the surface while the ground looked yellowish.

 

  Morning and Evening Condensates: In the preceding issue, we pointed that the morning Hellas began to look covered by a thick condensate mist in a complex manner: This time, PELLIER (CPl) depicted it on 7 Oct (λ=275°Ls) at ω=273°W etc. See also his B image on 11 Oct (λ=278°Ls) at ω=243°W. ESg also observed a bright core on the morning Hellas on the day at ω=213°W. This phenomenon was also caught by CIDADÃO (ACd) on 10 Oct (λ=277°Ls) at ω=246°W & 273°W, and by SANCHEZ (JSc) on 12 Oct (λ=278°Ls) at ω=249°W. DPk’s images on 14 Oct (λ=279°Ls) at ω=278°W ~ 295°W show that Hellas is considerably inside, but his B images prove still a white veil over Hellas. In fact it is suspected that Hellas in this period was covered by condensate mist throughout from morning to evening. DPk’s B images taken on 9 Oct (λ=276°Ls) at ω=333°W~349°W show that Hellas was considerably bright. This is also seen on GRAFTON (EGf)’s images on 11 Oct (λ=277°Ls) at ω=338°W, as well as on 14 Oct (λ=279°Ls) at ω=314°W. Furthermore, DPk’s B images on 13 Oct (λ=279°Ls) at ω=292°W~308°W seem to show that the white condensate covered the area of Iapygia Viridis to the north of Hellas. The images by JWr on 15 Oct (λ=280°Ls) at ω=318°W & 330°W further show that the condensate mist flew out to Æria to the north of S Sabæus. This must indicate a flowout of condensate along the equatorial zone in this season.

 

(NB): Several LtEs in the preceding issue suggested that a dust disturbance occurred at the area of Hellas around 5 ~ 10 October. As far as we see the ccd images which were submitted, however, there is no explicit evidence of such an occurrence: The images of Hellas and its environments do not show any particular difference from the former image eg by KOWOLLIK (SKw) made on 2 Oct (λ=272°Ls) at ω=312°W. The bright part of Hellas described on BUNGE (RBg) on 10 Oct (λ=277°Ls) at ω=316°W shows a typical and precise shape of the usual Hellas of this season (same as that in BENAVIDES (RBn)’s image on 5 Oct (λ=274°Ls) at ω=302°W). Any dust inside the high-pressured Hellas is a storm inside a teacup. As well, TES does not prove any other dust than the usual thin airborne near Hellas at this period of October 2003.

 

Mario FRASSATI’s Remark: MFr remarked on 6 Oct (λ=274°Ls) on his sketch at ω=249°W that there is a dust suspension over the area near Ausonia. MASSO (FMr)’s ccd image on 5 Oct (λ=274°Ls) at ω=267°W may also suggest similar brightness. However we consider that this area just shows the ground lit in the usual way. The present writer (Mn) had occasions this time also to see the tetra-like area of Eridania and southern Ausonia to be brilliant on 2 Oct (λ=272°Ls) at ω=203°W, 3 Oct (λ=273°Ls) at ω=204°W and so on, but judged the area to be normal. The TES result is also silent at this area.

 

  Tom DOBBINS’ Remark: TDb sent us an email (13 October at 3:49 GMT) with his image on 13 Oct (λ=279°Ls) at ω=295°W remarking "localized brightening in Hellas with apparent cloud cutting across Mare Hadriacum near Euripus into Ausonia." Except for the condensate cloud described above and the Ausonia brightness, his seems to point out the sandy light column area standing from Trinacria to the east of Hellas as often alluded to in #14 and #15.

 

Surroundings of the SPC: Any description of the spc by ccd is uneventful any more: No good images of Argenteus Mons and Rima Angusta are found: One of the best images are DPk’s R ingredients on 4 Oct (λ=273°Ls). Its colour compositions destruct the perimeter, and even show a fringe of pure red hue (being far from the wine colour). The contour of the spc should still be paid attention, and sometimes a dark fringe was watched and still a cascade seems to occur. For example, DPk’s spc on 9 Oct (λ=276°Ls) at ω=319°W shows partly a dark fringe, while the image on 10 Oct (λ=277°Ls) at ω=322°W does not. Both were obtained by the same ToUcam. The spc on his true set of composite images by an ST-9XE on 9 Oct are not sharp because of B, but their R components show well the interesting contour. The dark fringe of the IR image of ACd’s set on 6 Oct (λ=274°Ls) at ω=298°W looks similar to DPk’s on 9 Oct. EGf’s images on 11 Oct (λ=277°Ls) at ω=338°W shows the dark fringe strongly. Beyond the fringe, any image proves that the surroundings of the spc are faded in general, partly decoloured. TDb’s spc on 8 Oct (λ=276°Ls) at ω=347°W shows as if it ejected a cascade.

From the side of Japan, the surfaces mostly showed the area of Solis L and the spc from the sides looked very distinct (visually to Mn), and was associated with a fine dark fringe. Mn furthermore observed that the outside of the spc was largely faint in a shape of donut, partly faded in colour eg on 6 Oct (λ=274°Ls) at ω=128°W or on 7 Oct (λ=275°Ls) at ω=138°W, or on 9 Oct (λ=276°Ls) at ω=129°W. This may be produced on Ak’s images on 6 Oct. On 15 Oct (λ=280°Ls) at ω=054°W, Mn observed the faded donut ring looked faintly wine coloured. MURAKAMI (Mk) recorded on 9 Oct (λ=276°Ls) at ω=110°W & 119°W that the spc (totally inside the disk) was surrounded by a fainter and duller area.

Note also that the southern high latitude area near the terminator showed a white area misted or frosted: Mn’s records are as follows: on 2 Oct (λ=272°Ls) at ω=174°W(Thyle II light?), on 3 Oct (λ=273°Ls) at ω=175°W, on 4 Oct (λ=273°Ls) at ω=166°W, 180°W, on 6 Oct (λ=274°Ls) at ω=137°W, 147°W, on 7 Oct (λ=275°Ls) at ω=138°W, 157°W, on 8 Oct (λ=276°Ls) at ω=099°W, 109°W, 119°W (light in O56, but dull in G), on 9 Oct (λ=276°Ls) at ω=159°W, on 12 Oct (λ=278°Ls) at ω=104°W, and on 15 Oct (λ=280°Ls) at ω=025°W, 034°W, 044°W, 054°W, 073°W, 083°W, 098°W.

 

Relic of Novus Mons: Novus Mons already vanished as noted in a previous report but still the place where its ice presented or the trench is still identified. For example, DPk’s R images on 9 Oct (λ=276°Ls) at ω=333°W hint the place as decoloured. EGf’s image on 14 Oct (λ=279°Ls) at ω=314°W also suggests the segment.

 

  Maurice VALIMBERTI’s Remark: MVl sent us an email on 15 Oct at 15:30GMT suggesting that there is "a brightening at Southern latitudes from around Argyre to southern Dia & across to Noachis." The brightening is not so explicit or evident to us as far as we see his images on 14 Oct (λ=279°Ls) at ω=050°W et al, while it is certain that the area around Dia down toward the EN shows a sandy colour. This kind of surface nature might be the same as that seen outside the area where the decay of Thyles Mons took place. The present writer similarly recorded on 15 Oct (λ=280°Ls) at ω=054°W, 073°W, 083°W that there was seen a broad sandy band from the southern high latitude terminator to the EN direction; regarding this as a kind of fallout.

 

  Olympus Mons and Arsia Mons: Km’s images by the use of a 60cm Cass on 8 Oct (λ=276°Ls) at ω=115°W clearly show that the summit of Olympus Mons has a reddish hue. This kind of appearance of Olympus Mons is however quite different from that we saw in 1988 at the same Martian season: This time it was quite hard to distinguish visually the summit from the surroundings: this is said because Mn was watching on the same day under not-so-poor seeing condition. At ω=138°W, it showed up slightly vividly, but not enough. MVl’s image on 3 Oct (λ=273°Ls) at ω=163°W shows its more evening aspect, but the reddish ring should be said faint. At the same Martian season in 1988, Olympus Mons looked very apparent as a bright spot from the morning to evening, and quite different. In any case the summit had become free from the orographic cloud from λ=200°Ls, and so dull in general, while in 1988 the season corresponded to the opposition time, and hence we should regard in the 1988 case the opposition effect worked strongly. In 1971, the season came after opposition and δ was down to 14".

On the other hand, it is known that Arsia Mons continues to suffer from the condensate activity in the evening for a long time and should be supposed to be clouded up to this season. The Arsia cloud really once decreases at around λ=230°Ls, but soon becomes reactive from before the southern summer solstice. In 1988, at this period Arsia Mons was vivid in B while Olympus Mons was not (though evident in R and G). Here we cite a set exposed on H2 hypered TP2415 by Motomaro SHIRAO by the use of a 35 cm spec on 20 September 1988 (λ=275°Ls) where the B photo was obtained through B390. Thus the same phenomenon is expected to be caught.

However, this time the sunset line is already away to the rear side, and even if we pick out the Arsia Mons on MVl’s afore-cited image taken on 3 Oct (λ=273°Ls) at ω=163°W, it is still near at 1 o’clock PM (taking account ι=27°, and Arsia Mons’s longitude at Ω=120°W), and we can never say it’s in the evening. Even if Arsia Mons be on the limb, it must be just two hrs before the sunset, and hence we have to be much careful to the limb side. That is, we need good B images of ω=180~200°W.

Unfortunately we have not had pertinent images. Furthermore, as a general tendency, the more the phase angle increases, the more uncleared becomes the limb side of the ccd images. The present writer (Mn) visually observed on 4 Oct (λ=273°Ls) at ω=195°W (ι=28°) the limb side by the use of G filter: The limb was misty bright, but he could not identify the distinguished spot. The detection of the Arsia cloud at this season may be thus a theme handed over to 2005. In 2005, the southern summer solstice comes before opposition, and so observable though the angular diameter is not enough (around 14”).

 

NPH: Since the winter solstice came in the northern hemisphere, the behaviour of the north polar hood might be interesting (according to W H PICKERING, the nph is thick but the npc is not completed). However this period few special activities were observed. DPk’s images on 4 Oct (λ=273°Ls) at ω=017°W~077°W show well the nph covering M Acidalium. Note however the northern part of M Acidalium is seen through: On his R image, the district around 55°S is quite dark, not snowed. JWr’s images on 9 Oct (λ=276°Ls) at ω=039°W also depict well the nph, and on R, the northern end is dark. MVl’s description of the nph on 14 Oct (λ=279°Ls) at ω=050°W looks very real in density of the nph. Nothing in particular however in other longitudes.

 

Occultation of Mars on 6 October 2003: On 6 Oct, Mars was seen to be occulted by the Moon at Oceania including New Zealand and Australia. MVl sent us a beautiful set of images of the occultation from 16:32 to 16:39 GMT. Looks like the spc was grazed by the edge of the Moon. Since the images were taken by a 35 cm SCT, the surface of Mars is quite clear (ω=222°W).

 


T

he next issue shall treat the observations made in the Second half of October 2003 from 16 October (λ=280°Ls, δ=17.8") to 31 October 2003 (λ=290°Ls, δ=15.1").


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