8th Report: The CMO/OAA Observations made during the one-month period from

16 May 2003 (186Ls) to 15 June 2003 (204Ls)


An OAA Mars Section article to be published in CMO #273 (25 June 2003 issue)


Masatsugu MINAMI, Director of the OAA Mars Section


Japanese here


The planet Mars shined still lower, though slightly higher than in April. In mid-May, the apparent declination of the planet read - 19 while it rose up to -15 on 15 June: nearly the altitude we shall meet on the case of the opposition in August. We here review the observations made during the following period:

16 May 2003 at λ=186Ls to 15 June 2003 at λ=204Ls:

The Martian season was just after the southern spring equinox in mid-May, and corresponded to the period the 2001 dust cloud occurred, and the season in mid-June did to the period the Viking mission observed the first dust cloud. Thus we should say the season entered the very stormy period on Mars. The apparent diameter δ grew from 10.7 arcsecs to 14.2 arcsecs during the period. The central latitude φ became deep from 19S to 21S. The phase angle ι was from 43 to 41 and thus still the defect of illumination was strong.

In Japan, this was the rainy season. It started in Okinawa on 14 May in 2003 (on 8 May in 2002), and in the Kyushu district somewhat later on 9 June, and in the Kinki and the Kwanto district it began on 10 June. It started at the Hokuriku district including Fukui on 12 June. Usually it lasts for about one month or so.

 

We have received the observations from the following 34 observers. GRAFTON (EGf) joined us, and KUMAMORI (Km), LAZZALOTTI (PLz), BEISH (JBs) and others produced a continuous set of the routine observations.

 

AKUTSU, Tomio (Ak); Tochigi, Japan

13 Sets of CCD Images (24, 28 May; 2, 5, 8 June 2003)

f/3232cm speculum with a Bitran BJ-41L

ASADA, Tadashi (As); Munakata, Fukuoka, Japan

2 CCD Images (7 June 2003)

30cm SCT equipped with a Panasonic NV-MX5000

BALDONI, Paolo (PBl); Genova, Italia

1 Set of CCD images (13 June 2003)

20cm SCT with a Philips ToUcam Pro

BATES, Donald R (DBt); Houston, TX, USA

2 CCD Images (24, 31 May 2003)

f/2125cm speculum with a Philips ToUcam Pro

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

34 Drawings (16, - 22, 24, - 27, 29, - 31 May; 2, 3, 5,- 8, 10, - 15 June 2003)

440, 570, 650, 87041cm F/6.9 speculum

BIVER, Nicolas (NBv); Versailles, Yvelines, France

8 Colour Drawings (23, 29, 30 May; 6, 7, 9, 12, 14 June 2003)

41026cm speculum

FRASSATI, Mario (MFr); Crescentino, Italia

2 Sets of Drawings (7, 12 June 2003) 250, 40020cm SCT

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

5 Sets of CCD Images (31 May; 1, 3, 9, 15 June)

f/2735cm Celestron with an ST5

HERNANDEZ, Carlos E (CHr); Miami, FL, USA

       1 Drawing (11 June 2003)

250, 370, 44023cm Maksutov-Cassegrain

HIKI, Toshiaki (Hk); Minowa, Nagano, Japan

5 Drawings (1, 5, 6, 8 June 2003) 430, 39020cm speculum

ISHADOH, Hiroshi (Id);  Naha, Okinawa, Japan

      10 Drawings (19, 20, 21, 26, 31 May; 4, 5 June 2003)  

290, 400, 53031cm speculum

ISHIBASHI, Tsutomu (Is); Sagamihara, Kanagawa, Japan

4 B&W and Colour Photos (9 May; 6 June 2003)

31cm F/6.4 speculum; FCP400F, NP400P, HIE &TP

KOWOLLIK, Silvia (SKw); Stuttgart, Deutchland

1 CCD Image (12 June 2003)

18cm refractor with a Philips ToUcam Pro

KUMAMORI, Teruaki (Km); Sakai, Osaka, Japan 

11 CCD Images (17, 21, 23 May; 1, 2, 4, 5, 7, 8, 11 June 2003)

f/28, 4720cm Dall-Kirkham with a Philips ToUcam Pro

LAZZAROTTI, Paolo R (PLz); Massa,Toscana, Italia

16 Sets of CCD Images (17, 24, 25, 31 May; 1, 4, 5, 7, ~13 June 2003)

        18cm Maksutov-Cassegrain with an Astromeccanica KC381

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

      2 Red CCD Images (18 May; 10 June 2003)

20cm SCT with a Starlight Xpress MX5

MINAMI, Masatsugu (Mn); Mikuni, Fukui, Japan

59 Drawings (20, 21, 22, 23, 27, 28, 29 May; 1, 2, 5, 6, 8 June 2003)

400, 480, 60020cm ED refractor

MOORE, David M (DMr); Phnix, AZ, USA

11 Sets of CCD Images (16, 24, 30, 31 May; 4, 5, 6, 10, 11, 14, 15 June 2003)

f/3525cm speculum with a HX-5 or a Philips ToUcam Pro

MORITA, Yukio (Mo); Hatsuka-ichi, Hiroshima, Japan

26 Sets of CCD Images (17, 20, 23, 28 May; 1, 2, 3, 5, 7 June 2003)

f/5025cm speculum equipped with an ST-5C

MURAKAMI, Masami (Mk); Yokohama, Kanagawa, Japan

      10 Drawings (2, 7, 13 June 2003) 320, 40020cm speculum

NAKAJIMA, Takashi (Nj); Fukui, Fukui, Japan

8 Drawings (17, 23 May 2003) 40020cm ED Goto refractor

NARITA, Hiroshi (Nr); Kawasaki, Kanagawa, Japan

9 Drawings (21, 28 May; 1, 2, 3, 5 June 2003) 40020cm refractor

NG, Eric (ENg); Hong Kong

9 CCD Images (22, 26, 29, 30, 31 May; 1, 2, 4 June 2003)

f/3525cm Royce speculum with a Philips ToUcam Pro

PACE, Ben (BPc); Darwin, Australia

2 CCD Images (7, 9 June 2003)

f/2415cm Makstov with an HX516

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

27 Sets of CCD Images (20, 30 May; 1, 5, 11, 13 June 2003)

f/5541cm F/6 Newtonian equipped with an ST-9XE

PAU, K C (KPa); Hong Kong

6 CCD Images (21, 22 May; 1, 2 June 2003)

21cm spec (CN212) with a ToUcam Pro

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

14 Sets of CCD Images (26, 27, 28, 29, 31 May; 5, 6, 9 June 2003)

18cm Newtonian with a Philips ToUcam Pro

SEIP, Stefan (SSp); Stuttgart, Deutchland

3 CCD Images (7, 12 June 2003)

25cm Mak-Cass with a Philips ToUcam 740k

TAN, Wei-Leong (WTn); Singapore

3 Sets of CCD Images (24 May; 8 June 2003

f/2725cm Meulon with a Philips ToUcam Pro

TEICHERT, Grard (GTc); Hattstatt, France

3 Drawings (8, 12, 13 June 2002) 33028cm SCT

Van Der VELDEN, Erwin (EVl); Brisbane, Australia

3 CCD Images (18 May; 12, 15 June 2003)

f/3120cm SCT with a Vesta Pro modified

VALIMBERTI, Maurice P (MVl); Melbourne, Australia

10 CCD Images (22, 23, 24, 29 May 2003)

f/3435cm SCT with a Philips ToUcam Pro

WARELL, Johan (JWr); Tcuson, AZ, USA

       2 Drawings (14, 15 June 2003) 26025cm SCT (LX200)

ZANOTTI, Ferruccio (FZt); Ferrara, Italia

7 Sets of CCD Images (16, 25 May; 5, 8, 13, 15 June 2003)

            23cm SCT or 40cm spec with a Philips ToUcam Pro

Fukui City Observatory, Fukui

 

The Spc and Its Periphery: As already pointed out, the shadowy area inside the south polar cap (spc) began to be apparent from the southern spring equinox (λ=180Ls) at the beginning of May, and its detail became to be caught from around 19 May (λ=188Ls) in Japan (for example by ISHADOH (Id) at ω=127W and so on). PARKER (DPk)'s images on 20 May (λ=188Ls) at ω=310W - 320W seem to show Rima Australis as well as a germ of Novus Mons still inside the spc. MINAMI (Mn) on 23 May (λ=190Ls) at ω=041W noticed a bright spot at the peripheral area of the spc on the afternoon side which might be identified as a germ of Mons Argenteus. Similar zigzagged spots following peripheral areas were shown on VALIMBERTI (MVl)'s images taken on 23 May (λ=190Ls) at ω=063W - 078W which show as well the shadowy area inside the spc. We should say the bright spot which may be identified as Argenteus Mons was shot by LAZZALOTTI (PLz) on 10 June (λ=200Ls) at ω=020W. Around from 27 May (λ=192Ls), the peripheral contour of the spc looked much brighter than the inside area, showing that the periphery was now composed of water ice. At the same time the circumpolar fringe of the spc became broader and darker. On previous DPk's images on 20 May (λ=188Ls), the dark fringe to the south of Noachis is very conspicuous. The observations by Mn at the beginning of June showed however the dark fringe to the south of Hellas was narrower. The images by Van der VELDEN (EVl) on 15 June (λ=204Ls) at ω=211W shows however the fringe to the south of Ausonia was quite broad. As to the shadowy area inside of the spc, it depends on the processing, but it is also definite on many images including Eric NG (ENg)'s on 26 May (λ=192Ls) ω=077W et al. At Fukui, the detailed structure of the shadowy areas became much apparent from 5 June (λ=198Ls) and 6 June. The tint showed ochery, but ENg's images on 2 June and 4 June already showed the same. From American side, the image of GRAFTON (EGf) on 1 June (λ=195Ls) at ω=222W, clearly shows that the shadowy area inside the spc looked brownish. This image also shows a very zigzagged aspect of the contour of the spc at around Ω=250W. The description of the spc on DPk's images on 5 June (λ=198Ls) at ω=163W - 170W is excellent and seems to show an early stage of Thyles Mons. The file of MOORE (DMr) made on 6 June (λ=198Ls) at ω=189W features the details of the spc.

Dust Clouds: We need not be wondered if the dust cloud covered the surface at this season, but during the present period no global, macroscopic dust cloud was observed. Local dust disturbances were however noticed. On 21 May (λ=189Ls), Mn noted a small but bright dust disturbance at Syria Planum (following Solis L at Ω= 099W to 109W, Φ=10S to 18S) during the observations at ω=080W, 090W, 100W, 109W, and KUMAMORI (Km) shot it at ω=094W on the day (21 May). This was announced in emails in Japanese at 03:37GMT on 22 May, and around 24h we also sent an email to ask observations to Hong Kong, Australia and so on. We received responses from several observers including Don PARKER who hoped the disturbance could be minimal. On 2 June, the following site published an image on 21 June made by MGS-MOC:

http://www.msss.com/mars_images/moc/2003/06/02/

This dust did not develop: It rose weaker on 22 May (λ=189Ls) (MVl produced good images at ω=076W, PAU (KPa) at ω=096W, ENg at ω=110W, and at Fukui Mn observed at ω=070W, 080W, 090W, 100W) and on 23 May (Mn with NAKAJIMA (Nj)), and by 24 May it lost a regeneration as also shown by VMl, MORITA (Mo), Km, Mn, NAKAJIMA (Nj) (on 23 May), TAN (WTn) (on 24 May), and others.

Otherwise, MVl detected a suggestive light dusty streak at Eos Chasma on 29 May (λ=194Ls) at ω=009W which must have filled a valley at Eos. This seems also to be seen on the image by ENg on the same day at ω=045W. ENg observed succeeding days the same area but the streak was no longer definite.

Mare Erythrum: The apparent diameter increased enough to show some details of markings to compare with the known features (especially in 2001). DPk's images on 15 May (λ=185Ls) at ω=010W - 018W showed that the eastern part of M Erythrum and its north had been faded, and so the area between Margaritifer S and M Erythrum looked quite vacant. This seemed to be caused by a fallout of dust in 2001. From the end of May the area came into sight from Japan, and on 28 May (λ=193Ls), AKUTSU (Ak) at ω=011W, 021W, and Mo at ω=012W - 032W showed this fact. ENg's image of 2 June (λ=196Ls) at ω=000W shows this characteristic as well as the apparent Argyre.

Area around Solis Lacus: An impressive image of Solis L and its environments was given by PLz on 4 June (λ=197Ls) at ω=077W: It is just an R image, but shows a detail of the area of Phasis and Phoenicis L as well as a new feature of a rectangular light base to the east of nectar. DPk's images on 13 June (λ=202Ls) at ω=075W - 083W perfectly caught these features, and also did EGf's images on 15 June (λ=204Ls) at ω=089W. Newly darkened area around Araxes, which was previously reported based on DPk's images on 10 May, has been more explicit on DPk's images on 11 June (λ=201Ls) at ω=103W - 106W.

White Clouds at Tharsis: As well known since SMITH and SMITH who documented the behaviour of Olympus Mons throughout the Martian seasons (once introduced ten years ago in CMO#134), the topographic cloud over Olympus Mons becomes inactive by λ=180Ls, while the cloud over Arsia Mons is known to continue to be active. The latter fact was quite observed in 1988 and 1990. However in case the dust covering prevails as in 2001, the activity ceases (in 2001 at around λ=190Ls). This time the condensate cloud associated with Arsia Mons was well observed. Its preceding activity was reported previously, while this time the Arsia cloud near the terminator was checked from the Orient on 17 May (λ=186Ls) at ω=127W by Mo and at ω=130W by Km, and on 18 May (λ=187Ls) at ω=131W by EVl at Oceania. ISHADOH (Id) watched it visually on 19 May (λ=188Ls) at ω=127W, and on 20 May (λ=189Ls) at ω=124W (more inside). On 25 May (λ=191Ls) PLz in Italia showed it on B at ω=155W, and on 28 May (λ=193Ls), and 31 May (λ=195Ls), PELLIER (CPl) showed it at ω=153W and ω=130W respectively in B (still by W38A). BIVER (NBv) visually detected it on 29 May (λ=193Ls) at ω=141W. The outstanding images then came: DPk's images on 5 June (λ=198Ls, δ12.9") at ω=163W - 170W proved that the Arsia topographic cloud was thick at the evening side while Olympus Mons was very free from the condensate cloud though looked roundish bright. EGf's images on 9 June (λ=200Ls) at ω=138W also shows the same aspects. They show how wide the Tharsis cloud is spread and so these will be useful to check the spatial distribution of the up-slope winds as well as the morphology of the Tharsis area including Pavonis Mons and Ascrus Mons. On 10 June (λ=201Ls), MOORE (DMr)'s B showed it at ω=144W. DPk's B images on 13 June (λ=202Ls) at ω=080W show that the Tharsis cloud appears early in the afternoon. See also EGf's B image on 15 June (λ=204Ls) at ω=083W. The classical paper by SMITH and SMITH is found in Icarus 16 (1972) 509, and as to the recent results by the use of the MGS images, see J L BENSON et al, Icarus 165 (2003) 34. These results are useful to judge the outcome in 1988 and 1990, as well as in looking over the old results by LOWELL and BARNARD in 1894.

Elysium: Inside the light Elysium, a Y shaped dark streak (also seen in 2001 is visible in DPk's images on 30 May (λ=194Ls) at ω=215W as well as in EGf's image on 3 June (λ=196Ls) at ω=204W.

 

The theria Dark Patch: The dark patch in theria slightly changed its shape after the dust event in 2001. This year the patch appears quite dark and definite and looks to preserve still the post-dust shape. DPk's images on 30 May (λ=194Ls) at ω=229W show the bright swatch following the dark patch.

Evening Mist over Syrtis Mj: The B images of DPk made on 20 May (λ=188Ls) at about ω=310W - 325W caught an up-slope evening mist over Syrtis Mj. On 2 June (λ=196Ls) at ω=320W, MURAKAMI (Mk) at Yokohama had a chance to visually watch the sinking Syrtis Mj over which the mist flowed out lightly to eria.

Hellas: Atmospheric disturbance around the area of Hellas is an index of the coming atmospheric situation, though the commonly accepted legend that any great dust storm originates from the inside of Hellas is quite erroneous: The Hellas basin is governed by the high atmospheric pressure and so any air mass if dusty cannot burst out of the basin in general. This period the basin looked dull with a shadowy segment inside the Hellas. However at the beginning of June, the south-western part of Hellas showed a light swath along the western border (this was also observed in 2001). On 5 June (λ=197Ls), it was proved by Mo at ω=301W - 306W, and by Km at ω=304W, and also a little by Ak. On 7 June (λ=199Ls) it was also apparent on the images by Mo at ω=273W - 291W, by Km at ω=283W, and by As at ω=286W. At Fukui, this was also checked visually from 5 June: the preceding area of Hellas was dull if it approached the terminator. Mn's observations were as follows: On 5 June at ω=266W, 276W, 286W, 296W, 305W, 315W & 325W, on 6 June (λ=198Ls) at ω=277W, 286W & 296W, clouded, and on 8 June (λ=200Ls) at ω=(228W, 238W, 248W), 257W, 267W, 277W & 286W (at 19:50GMT). The SW swath was brighter at S. This stripe was also taken earlier by DPk on 20 May (λ=188Ls) at ω=310W.

Yaonis Fr and M Serpentis: As described above, the observations around 5 June showed that the following border of the bright SW swath of Hellas was quite dark adjacent to the dark fringe of the spc, while the northern Yaonis Fr itself was quite faint. M Serpentis was not so prominent but composed of a few dark dots, and looked to be separated from S Sabus. Yaonis R is rather light. These aspects are shown in several ccd images,, but here as a representative we shall pick out the ones made by WTn on 8 June (λ=200Ls) at ω=324W.

Eridania/Electris: The images by PLz on 24 May (λ=190Ls) at ω=186W, and by CPl on 26 May (λ=192Ls) at ω=180W show that Eridania at the rather morning side is light. EGf's image on 3 June (λ=196Ls) at ω=167W, and DPk's ones on 5 June (λ=197Ls) at ω=163W - 170W prove that Eridania and Electris are surface lit; the more morning side being whitish misty.

Ausonia Borealis and M Hadriacum: LPz's Red image on 17 May (λ=186Ls) at ω=253W, though small, shows that Trinacria (Ausonia Borealis) became rather light (different from the aspect in 1988), and M Hadriacum was also faint. Because of the latter, the eastern border of Hellas looks ambiguous. The faintness of Trinacria was then caught in America: EGf's images on 31 May (λ=195Ls) at =230W, and on 1 June (λ=195Ls) at =222W showed the fact, though the angle was shallow. In Japan, Km's image on 11 June (λ=201Ls) at =245W proves similarly. These aspects of M Hadraicum and Trinacria are considerably different from those we observed in 1988, and we consider that these devastations of the dark areas were caused by the fallout of the 2001 dust.

The North Polar White Hood: Since the tilt of the north pole was quite away from the Earth to the extent from φ=19S to 21S, it was not easy to watch the north polar region. Visually however it was apparent the northern limb was covered by the north polar hood (nph), while the northern to western limb side on the stacked ccd images appeared not credible during the time when the phase angle ι was larger. Just DPk's images on 20 May (λ=188Ls) at ω=310W - 325W definitely show that the nph grows north of Ismenius L and so southward from 50N to 55N. The mildly processed good image by MVl on 24 May (λ=191Ls) at ω=032W also shows that the npc clearly covers the northern half of M Acidalium. The boundary is quite northward of Achillis Pons, and so lies north of 55N. ENg's image on 30 May (λ=193Ls) at ω=025W shows the similar aspect. At these areas, it is also interesting to see how the nph declines to the morning side when M Acidalium stays on the more morning side: Ak's images on 28 May (λ=192Ls) at ω=011W, and ENg's one on 2 June (λ=196Ls) at ω=000W provide the examples, as well as the B image by PLz made on 12 June (λ=202Ls) at ω=359W, and the drawing by NBv on 12 June (λ=202Ls) at ω=002W.

Otherwise, DPk showed on 5 June(λ=198Ls) at ω=163W - 170W that the nph spans north of 50N - 55N while Propontis I clearly popped out. At the hemisphere where Solis L was present, DMr's images on 15 June (λ=204Ls) at ω=104W describe the nph.

Anthological: Not well chosen, but the following images were impressive when reviewing: VMl's image on 24 May at ω=032W, ENg's one on 2 June at ω=000W, DPk's (out of many) image on 5 June at ω=163W, PLz's one on 8 June at ω=040W (when δ13.3") and possible others.

 

Mourning: We miss Tom CAVE (TCv): It was sad to hear the passing away of Tom on 4 June when the planet was approaching. Tom was born in 1923, and hence he lived one cycle of Mars. It is a good memory for us to have been able to cultivate friendship with him: Our essay on Tom appeared in CMO #198 (25 December 1997 isuue). Tom DOBBINS gave the following tribute to Tom CAVE:

http://skyandtelescope.com/news/article_974_1.asp  

See also the following memorial articles: One was written by Phil HALLINGTON and the other by Larry ADKINS

http://www.astronomy.com/Content/Dynamic/Articles/000/000/001/371sejig.asp

http://www.cerritos.edu/ladkins/Cave/thomas_cave_observatory.htm

 


The next issue shall treat the period from 16 June (λ=204Ls) to 30 June 2003 (λ=213Ls, δ=16.5"). The present writer goes to Okinawa to observe Mars from 23 June.


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