2001 Mars Observation Reports -- #22--

OAA MARS SECTION

CMO Mars Observations
in the Second Half of March 2002 and the First Half of April 2002
from 16 March 2002 (343Ls) to 15 April 2002 (358Ls)
based on the article published in CMO #259 (25 April 2002)


by Masatsugu MINAMI, Director of the OAA Mars Section



T

HIS time we treat the period from

16 March 2002 (343Ls) to 15 April 2002 (358Ls)

The season is now quite close to an end, and the observation frequency has been lessened. On 16 March, the apparent angular diameter was just 4.6", and further went down to 4.2" on 15 April. Though the apparent declination has gone higher every day (+21on 15 April), the planet is quite low just above the Sun, and hence the surface contrast has been lower even at the time of Sundown. From mid-March the Japan islands suffered strongly (said recorded) from the yellow sand outflow aloft from the China Continent, so that the sky has been not clear (see some of NOAA or MISR images). We are not sure about the relationship, but the temperature in March recorded also higher than usual, and the Cherry Trees were at their best about ten days earlier than usual, and so the blossoms immediately scattered quite before the expected days in April.
  The central latitude changed from 18S down to 11S during the period. The phase angle decreased from 28to 22.

O

BSERVERS are still trying to find good seeing. KUMAMORI (Km) produced some good images. MORITA (Mo)'s images are sometimes unstable, but still he tries. ISHADOH (Id) could not find observable conditions during the period. The present writer (Mn) was busy in March, but met better weather in April.

KUMAMORI, Teruaki (Km) Sakai, Osaka, Japan

8 CCD Colour Images (19, 28, 30 March; 2 April 2002)

60cm Cassegrain# with a Sony TRV-900

# Sakai City Observatory

MINAMI, Masatsugu (Mn) Fukui, Japan

29 Drawings (16, 20 March; 2, 4, 5, 7, 9, 12, 14 April 2002)

600, 480, 400x 20cm ED Goto refractor *

* Fukui City Observatory

 

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

21 Sets of CCD Images (16, 17, 20, 21, 30, 31 March; 5, 7, 13 April 2002)

f/50 25cm speculum equipped with an ST-5C

MURAKAMI, Masami (Mk) Fujisawa, Kanagawa, Japan

1 Drawing (17 March 2002) 320x 20cm peculum

 

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

1 Set of CCD Images (30 March 2002)

f/55 41cm F/6 Newtonian equipped with a Lynxx PC

PEACH, Damian (DPc) Rochester, Kent, UK

2 Sets of CCD Images (23, 28 March 2002)

f/29 31cm Meade SCT with an ST-5C

Observations:
 
ON 16 March (343Ls), Mn observed from LCM=171W (8:40 GMT) to LCM=190W: The dark band was visible, and M Sirenum looked darker on the afternoon side, and sometimes it combined with a dark area at the morning side as two spots. The spr was dull light. Temperature inside the dome was 13C. On the same day MORITA (Mo) shot at LCM=186W~201W: Besides the dark M Sirenum, they show a shadowy area near Cerberus in the morning.

  On 17 March (343Ls), MURAKAMI (Mk) watched at LCM=171W (the central latitude=18S): He also saw a bent dark band from M Sirenum to M Cimmerium. The spr looked whitish light. 15C. Mo at Hiroshima took the images at LCM=179W, 189W: The images are unstable except a west end of M Sirenum.

  On 19 March (344Ls), KUMAMORI (Km) produced the images at LCM=142W, 147W: they show a dark band from Ddalia to M Sirenum, and also an unidentified dark spot on the NH.

  Mn, returned from Kyoto to watch the Saturn occultation, watched Mars on 20 March (345Ls) at LCM=124W (8:10GMT), 134W, 144W, 153W (at 10:10 GMT) just before the occultation. The Ddalia dark area was seen to M Sirenum, and the EN limb of the spr was whitish light. At LCM=153W, the northern neighbour of the main dark band was misty whitish. At LCM=144W, the morning side of the band looked bluish though the seeing was poor. Saturn totally occulted but nearly grazed and reappeared within half an hour (Titan was not). Unfortunately the seeing was not enough to watch the details of the rings. 16C. At Hiroshima, supposed no Saturn occultation was seen, Mo was taking ccd images of Mars from LCM=144W to 160W. Some show Ddalia, and another M Sirenum. The B images are featureless.

  On 21 March (345Ls), Mo tried around at LCM=140W, but the results are not satisfactory.

  On 23 March (347Ls), PEACH (DPc) in England produced a good set at LCM=247W (at 18:38 GMT): The IR image shows the spc? M Cimmerium shows inner details. The (supposed) IR rejected G image shows some markings as in IR. The continent to the south of M Cimmerium is surface lit. Hellas is not light in B, but maybe slightly misty.

  On 28 March (349Ls), Km obtained images at LCM=055W, 061W (at 09:15 GMT), and DPc at LCM=191W (at 18:09 GMT):

  Km's images might be important in the sense that they show a brow nish tinge at the dark area of Auror S (as well as the morning Solis L?), which look different from the colour of the area of M Erythrum. Such a colouring has usually been known near Phlegra and as noted in the preceding issue (Note (4)) around the summit areas of Montes in Tharsis in July 2001. Km's images also show clearly the white north polar hood (nph).
 About nine hours later, DPc took images where several minor dark and light markings on the NH as well as the dark band from M Sirenum to M Cimmerium are shown in IR as well as clearly in G. The B image does not show any clear bit of the
nph.

  On 30 March (350Ls), Don PARKER (DPk) produced an excellent set of images at LCM=270W (at 00:13 GMT), Km shot at LCM=040W (at 09:10 GMT), and at 045W, and then Mo at LCM=051W, 055W, 061W, & at 067W.
  DPk's images show the mouth of Hesperia, and the long-lost Mris L. Hellas is slightly obvious in G, but not in B. In SMITH-SMITH,
Hellas usually shows a second (but weaker) peak near 330Ls but soon lessens the brightness, and so DPk's result may well be consistent at 350Ls. As to Mris L, if it turns to clearly show up in 2003, it will come after about 50 years since 1954.

  Nine hours later, Km produced images showing the area of Auror S, repeating the features detected on 28 March. The white nph is also apparent. In the following images of Mo, the areas of M Erythrum and Auror S are dark and on the NH the area of Niliacus L to Nilokeras is visible in R and IR. The B image at LCM=066W, the nph is shot.

  On 31 March (351Ls), Mo tried at LCM=041W~051W, but the seeing was poorer.

  On 2 April (352Ls), Mn, who just retired on 31 March, watched Mars after an absence at LCM=007W~026W: It was hard any longer to detect minor markings since the apparent angular diameter was 4.3", while the presence of the large dark markings was obvious. The dark band in Noachis and M Erythrum looked dark. The spr was whitish, and Hellas was off-white near the afternoon limb. The northern limb also whitish. The Sun sunk in the west at around 9h GMT (18h JST).

  On the day, Km took images at LCM=012W, & 018W: The former is excellent and stable made from 332 frames. S Sabus and S Meridiani are evident, and the tip and is conspicuous related with M Erythrum. Niliacus L is apparent adjacent to the white nph. The central latitude =14S.
  On 4 April (353Ls),
Mn watched from LCM=342W to 006W: The seeing was poor, but Hellas was slightly light near the plimb.

  On 5 April (353Ls), Mn watched from LCM=245W to 004W, and Mo obtained IR images at around LCM=010W. Hellas was light near the plimb and the limb-lightening crept up to the spr. The dark markings from S Sabus to M Erythrum were vaguely known.

  On 7 April (354Ls), Mn observed at LCM=320W, 330W, 340W, and Mo took images at LCM=335W, 340W, 346W, 351W. Mn saw Syrtis Mj which became fainter later, while S Sabus became more apparent. The spr looked misty including the area of Hellas, but later Hellas was indistinguishable. The IR images of Mo show clearly the shape of the afternoon Hellas as well as the dark markings as Syrtis Mj and S Sabus ( LCM=334W~343W). Hellas is however obscure in B. Therefore Hellas is not atmospheric, but surface lit.

  Mn observed on 9 April (355Ls) at LCM=308W, 318W, and on 12 April (357Ls) at LCM=264W~293W: Syrtis Mj was apparent. Hellas was near the CM, but never light though outlined. At LCM=284W on 12 April M Serpentis was separated from S Sabus in the morning.

  On 13 April (357Ls), Mo took images at LCM=287W: Syrtis Mj was dark and Hellas is featured in IR.

  On 14 April (358Ls), Mn watched at LCM=245W~264W: The area of M Cimmerium was seen. The spr was whitish, and the plimb and the northern limb looked light. The season of autumnal equinox was very ahead on the SH, and on the NH it was expected the nph was nearly the largest.

We further received as follows:

ISHIBASHI, Tsutomu (Is) Sagamihara, Kanagawa, Japan

7 B&W Images (23, 30 July; 3, 17, 27 August; 12, 25 September 2001)

31cm f/6.4 speculum; HIE, NP400P and TP

 

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

3 Sets of CCD Images (11, 13 March 2002)

f/55 41cm F/6 Newtonian equipped with a Lynxx PC

Is's B images in July 2001 (at LCM=020W on 23 July and at LCM=286W on 30 July) show the thick nph and the morning frost following the spc, but other wave lengths did not produce any dark marking. At the end of September 2001, Is feels that the markings are coming, but not yet explicit.

  DPk's images should be added to those in the preceding issue: The images on 11 March (340Ls) 2002 is an R image at LCM=108W where the Ddalia patches are shown. On 13 March (341Ls) DPk shot at LCM=076W & 080W: Auror S is dark and the coming dark spot in the Solis L area looks brownish. The nph is not explicit. On the same day, as already reported in #258, Km observed 9 hours later at LCM=214W. The nph is shown on Km's image at LCM=061W on 28 March (349Ls).


  THE next report in #260 shall deal with the observations during a one-month period from 16 April 2002 (359Ls) to 15 May 2002 (013Ls).


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


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