2001 Mars Observation Reports -- #22--

2001 Mars Observation Reports -- #08--

OAA MARS SECTION

Mars Observations
in the First Half of May 2001
from 1 May 2001 (154°Ls) to 15 May 2001 (162°Ls)
based on the article published in CMO #244 (25 May 2001)

by Masatsugu MINAMI, Director of the OAA Mars Section

HE apparent diameter of the planet on 1 May 2001 (154°Ls) was 14.3" while it augmented to 16.6" on 15 May 2001 (162°Ls). The angular diameter is thus enough, but the apparent declination went down nearly to -25°. Quite low from the NH. The central latitude read a extremum at 1.9°S on 3 May, but went back to 1.5°S on 15 May. The phase angle went down from 29° to 22°.

We received the observations from 20 observers with thanks as follows:

AKUTSU, Tomio (Ak) Karasuyama, Tochigi, Japan

2 Sets of CCD Images (5 May 2001)

f/70, 32cm spec equipped with a Teleris 2

BIVER, Nicolas (NBv) Versailles, France

8 Colour Drawings (17, 19, 23 March; 1, 12 April; 12, 13 May 2001)

330,510x 26cm speculum

CAVE, Thomas R (TCv) Long Beach, CA, USA

2 Drawings (6, 9 May 2001)

280, 430, 380, 550x 33cm speculum

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

2 Sets of CCD Images (10, 14 May 2001)

f/60, 35cm Celestron SC equipped with an ST6

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

1 Drawing (12 May 2001) 220x 20cm Schmidt-Cassegrain

HIGA, Yasunobu (Hg) Naha, Okinawa, Japan

16 Video Images (2, 3, 15 May 2001)

25cm f/6.7 spec equipped with Sony VX-1000

HIKI, Toshiaki (Hk) Minowa, Nagano, Japan

2 Drawings (12 May 2001) 430x 22cm speculum

ISHADOH, Hiroshi (Id) Naha, Okinawa, Japan

4 Drawings (2, 15 May 2001) 400, 530x 31cm speculum

KUMAMORI, Teruaki (Km) Sakai, Osaka, Japan

1 CCD Colour Image (13 May 2001)

20cm f/12 Dall Kirkham, Mintoron MTV-6368

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

2 Sets of CCD Images (2, 12 May 2001)

20cm Celestron SCT with a Starlight Xpress

MINAMI, Masatsugu (Mn) Fukui, Japan

45 Drawings (4, 5, 10 ~ 13 May 2001)

400, 480x20cm refractor*

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

23 Sets of CCD Images (3, 10, 11, 12 May 2001)

f/50, 25cm spec with an ST-5C

MURAKAMI, Masami (Mk) Fujisawa, Kanagawa, Japan

15 Drawings (6, 11, 12, 13 May 2001)

400, 320x 20cm speculum

NAKAJIMA, Takashi (Nj) Fukui, Japan

8 Drawings (4, 12 May 2001) 400x 20cm refractor*

NARITA, Hiroshi (Nr) Kawasaki, Kanagawa, Japan

10 Drawings (1, 6, 7, 12, 13, 14 May 2001)

400x 20cm refractor

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

3 Sets of CCD Images (13 May 2001)

f/49, 41cm Meade SCT with a Lynxx PC

PEACH, Damian A (DPc) King's Lynn, Norfolk, UK

3 Colour Drawings (8, 9, 11 May 2001)

405x 31cm Meade SCT

TEICHERT, Gérard (GTc) Hattstatt, France

3 Drawings (11, 12, 13 May 2001)

330, 310x 28cm Schmidt-Cassegrain

TSUNEMACHI, Hitomi (Ts) Yokohama, Kanagawa, Japan

24 Drawings (3*, 4*, 5*, 12 May 2001)

360x 12.5cm Fluorite refractor/ 400x 20cm refractor*

WASIUTA, Myron E (MWs) VA, USA

13 Drawings (1 ~ 4, 11 May 2001) 360x 32cm speculum

* Fukui City observatory

THE observations were made as follows:

1° Decay of the activity of the Libya evening cloud:

From Japan the evening Libya region came into sight from around 10 May (159°Ls), while its cloud activity looked much weaker than the previous case around 145°Ls: This may also depend on the difference of the phase angle : it was previously 35° but 25° this time.
MURAKAMI (Mk) noticed however on 12 May (160°Ls) at LCM=351°W that the southern part of Syrtis Mj was faded near the terminator because of the covering by the Libya mist. On 13 May (161°Ls) at LCM=349°W, Mk observed that the haze was also related with Hellas through Iapygia Viridis. Already Mk rightly pointed out on 12 May (160°Ls) at LCM=319°W that the south of Syrtis Mj including the area of Iapygia Viridis looked faded.
The present writer (Mn) obtained similar results from 10 May (159°Ls), and thought as to the Libya evening mist that the mist was directly related with the gradual fading of the east coast of Syrtis Mj from around LCM=330°W. In general Syrtis Mj becomes slim at the evening side because of the slope where it lies, but this time Syrtis Mj looked rather fat near the terminator perhaps because the east coast was blurred by the presence of the mist, and the mist looked rather grey. Typically Mn observed so on 12 May (160°Ls) at LCM=341°W and on 13 May (161°Ls) at LCM=329°W. The Libya mist did not look whitish, but quite thick and might have caused a complex refraction.

2° Hellas and the area south of Syrtis Mj:

The northern Hellas was already free from the white cloud even near the evening terminator and the boundary of Hellas became blurred. Furthermore the area including Iapygia Viridis appeared faded just like the inside of Hellas to the extent that the boundary of Hellas looked to have receded, or as if moved toward north. This aspect was also observed in 1969 at the same season. Due to the evening haze, the dark markings became faded near the terminator, and the light areas became rather shadowy as if the not-glittering evening mist were just like a grey mist uniformly and monotonously covering the evening terminator as was typically observed on 12 May (160°Ls) at LCM=341°W (the one as already cited). This was also suspected in 1969 (observed in Japan around from 169°Ls), and so may be representative of the season.
Even then the Libya mist is originally whitish, and the image by KUMAMORI (Km) at 13 May (161°Ls) at LCM=334°W yet shows a slight whiteness though the northern Hellas is off white. HIGA (Hg)'s image on 15 May (162°Ls) at LCM=327°W also yet discriminates the dark marking from the Libya mist as well as Hellas (not yet near the terminator).

3° The sph and the spc:

As to the south polar hood/cap, the superb images produced by Ed GRAFTON (EGf) and Don PARKER (DPk) on 10, 13 and 14 May are suggestive: On 10 May (159°Ls) EGf obtained a set of images at LCM=247°W, on 13 May (161°Ls) DPk at LCM=224°W, 230°W, LCM=235°W and on 14 May (161°Ls), EGf at LCM=226°W.

DPk's B images show that the sph covers Ausonia Australis down around to 50°S, while the R images penetrates the outskirts of the sph into the ground of Ausonia Australis. The question is whether the perimeter of the spc is down to Ausonia Australis.
EGf's LRGB image may contain several markings shown by the Infrared (IR) longer wave lights, and the images on 14 May (161°Ls) suggest that the border of the spc is not down to Ausonia Australis, but stays near around at 60°S. The hi-resolvable L image (by the use of a magenta filter) however shows a hazy matter haunting near the perimeter. The freezing of CO2 must have been at a maximum near around 150°Ls, and so the period already passed, but we should be still on the alert since it is highly possible for the H2O ingredient to become frozen outside 60°S.

4° The dark arch in Noachis:

The broad band near M Serpentis was made of Yaonis Fr and M Serpentis separated by Yaonis R. Notable is the big arc band that starts from M Serpentis to the far west. The band is different from Pandoræ Fr. This broad arch looks quite the same as observed in 1984 (not yet at 130°Ls, but observed since 166°Ls (on 19 June 1984)), and similarly also as in 1984, the eastern part looked made of several dark patches (as shot this time by MORITA (Mo) on 11 May (160°Ls) at LCM=000°W and observed by Mn on 12 May (160°Ls) at LCM=341°W and 351°W). M Serpentis should be said to be disconnected from S Sabæus.

5° The sph to the west of Hellas:

At around 161°Ls (13 May), the southern Hellas looked hazed in the evening though the haze was separated from the sph by a shadow at around LCM=310°W. The following sph was however not deep but just present narrowly near the southern limb from these angles. The further following morning side then gradually became brighter, maybe as the area of Argyre showed up. Furthermore Argyre moved to the evening side, as far as we observed for example on 4 May (156°Ls) at LCM=091°W, another bright part appeared to the south of M Sirenum to the extent the middle area looked shadowy especially at the southern limb.
As to the Argyre area, Hg already made the Video images on 3 May (156°Ls) at LCM=056°W ~ 075°W where the brighter part at Argyre was already shown, TSUNEMACHI (Ts) also recorded it on both 4 and 5 May (156°Ls) at LCM=052°W and also AKUTSU (Ak)'s Int image on 5 May at LCM=051°W clearly shows this bright patch (Ak's following RGB images at LCM=077°W are much better, but Argyre is no longer seen). The bright area of Argyre is also shown on Mo's images on 11 May (160°Ls) at LCM=019°W and 030°W. It was also clearly observed by Mn on 11 May (160°Ls) from LCM=005°W to 046°W; the sph following Argyre at LCM=046°W appeared suddenly very weak. On 12 May (160°Ls) at LCM=010°W the bright area looked as if it protruded from the sph. The broad tail was to the southern limb. HIKI (Hk) also observed the irregularity of the Argyre part on 12 May (160°Ls) at LCM=010, 020°W.
We recommend the readers to refer to EGf's image taken on 30 April (154°Ls) uploaded at http://www.ghgcorp.com/egrafton (http://www.ghg.net/egrafton) in which the Argyre part looks brighter than the surrounding sph. Japanese readers can also refer to the TENMON NENKAN 2001 to find Mn's drawing made on 7 June 1969 (169°Ls) where Argyre looked protruded down from the sph before the spc popped out. This implies the aspect remains stationary nearly for one month (nearly longer than 15°Ls).
On 13 May (161°Ls) at LCM=359°W ~ 008°W, Mn saw several light patches inside the spr were preceding the Argyre bright patch. To shoot these aspects, we will need a set of Integrated ccd images allowing more infrared lights. Inspired by the work of EGf, Mo now began to concentrate on the L channel, but not yet in mid-May. As to EGf's method, see the LtE this issue, and also refer to the Web Page: http://www.ghgcorp.com/akelly/artdraf7.htm

6° Other details:

The morning white mists were still active at around 160°Ls, for example at Chryse. On 6 May (157°Ls), Mk observed a whitish matter in Chryse much inside (at LCM=036°W & 046°W), and this was connected with the evening mist. Mn also detected a lighter area in Chryse near Niliacus L on 11 May (160°Ls) at LCM=024°W & 036°W.

The evening mist, just like the Libya cloud, was not so strong, while the Xanthe evening cloud was recorded bright by Ts on 5 May (156°Ls) at LCM=081°W and so on, and the successive images by Mo on 3 May (155°Ls) show how the Xanthe evening mist develops ( ~ LCM=106°W). The mist seemed to be whitish bright if it covered such a light area as Xanthe, and greyish if the ground was such a dark marking as Syrtis Mj.
Elysium was brighter in R than in B on DPk's images at 161°Ls. Elysium Mons itself looks clouded but small, complicated in EGf's images (one hour and half PM LMT).
Fine structures were about to show up: the spot we called Grace's Fons in 1986 inside the Huygens crater was visible now and then, and the shadowy but delicate segment starting from Phœnicis L to Arsia Mons was easily visible. M Sirenum looked like as in 1986, and Aonius S also looked elongated to the west. Dædalia appeared rather shadowy.

It is known that the aspect of the dark markings at the south circumpolar high-latitude region in the southern later summer is different than that in the southern spring: Especially the southern Noachis including Depressiones Hellesponticæ down to Yaonis R, and the area to the south of M Sirenum should be intensively watched in spring. These must be related with an activity of the H2O near the perimeter of the spc.

For a while, the CMO shall be published twice a month. The next issue shall review the observations made during a fortnight period from 16 May (162°Ls) to 31 May 2001 (170°Ls).
Our CMO Internet Web-Site has a Gallery Page where some new Mars images are flashed before our reviewing.
We hope every CCD image is emailed in a jpg file with a file name beginning with the observer's name to vzv03210@nifty.com as well as to cmo@mars.dti.ne.jp. Drawings are preferred to be sent in an A4 sized format with just one drawing on one sheet.

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

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