2001 Mars Observation Reports -- #05, Revised --
OAA MARS SECTION
made during the period
from16 February 2001 (118°Ls) to 15 March 2001 (131°Ls)
based on the article published in CMO #241 (25 March 2001)
by Masatsugu MINAMI, Director of the OAA Mars Section
On 15 March the Moon near the last quarter (slightly gibbous) came near the planet Mars to the north by 1° 47 '; implying that the planet rose at midnight and would disappear at daybreak. The Martian season of 131°Ls on 15 March corresponds to the season we met last in 1999 near at opposition, and so we shall observe hereafter the Martian season which we observed in 1999 when the diameter was descending.
he season on our side also drastically changed: On 16 February the roof top of the Observatory was quite white with snow and the temperature was down to -3°C in the early morning, while on 15 Mar it was rather warm with 4°C outside of the dome. On 19 Mar it went up to 9°C at midnight.
This time we acknowledge receipt of 147 observations from the following 13 observers:
AKUTSU, Tomio (Ak) Karasuyama,
1 Sets of CCD Images (12 March 2001)
f/60 32cm spec equipped with a Teleris 2
HERNANDEZ, Carlos E (CHr)
1 Set of Drawings (6 March 2001)
410, 470x 20cm SCT
HIGA, Yasunobu (Hg)
26 Video Images (18, 19, 21, 27 February; 2, 5, 6 March 2001)
25cm F6.7 spec equipped with Sony VX-1000
ISHADOH, Hiroshi (Id)
12 Drawings (18, 19, 21 February; 9, 14 March 2001)
400, 530x 31cm speculum
MELILLO, Frank J (FMl)
1 CCD Image (19 February 2001)
20cm SCT equipped with a Starlight Xpress MX-5
(16, 17, 19, 20, 22, 26 February; 2, 11, 13, 15 March 2001)
375,400,480,600,630x 20cm refractor*
MORITA, Yukio (Mo) Hatsuka-ichi,
18 Sets of CCD Images
(19, 20, 22, 26 February; 8, 10, 11, 15 March 2001)
f/50 25cm speculum equipped with an ST-5C
MURAKAMI, Masami (Mk)
8 Drawings (16, 18, 21, 22, 26 February; 13 March 2001)
320,425x 20cm speculum
NAKAJIMA, Takashi (Nj)
7 Drawings (22 February; 13 March 2001)
375,400x 20cm refractor *
NISHITA, Akinori (Ns)
3 CCD Images (13, 15 March 2001)
f/190 20cm refr* equipped with an Apogge AP7p
PARKER, Donald C (DPk)
6 Sets of CCD Images (27 February; 1, 4 March 2001)
f/55, 62 41cm speculum equipped with a PixCel 237 camera
PEACH, Damian A (DPc) King's Lynn,
1 Drawing (8 March 2001) 405x 31cm Meade SCT
WASIUTA, Myron E(MWs) VA,
10 Drawings (18, 24, 27 February; 1, 10, 12 March 2001)
360x 31cm speculum/360,440x 16cm refractor
16 ~ 28 February 2001
the Japanese side, observed densely for 7 days from 16 February (118°Ls) to 22
February (121°Ls) the region from LCM=034°W to LCM=130°W: during which 55
numbers of observations were recorded.
On 16 Feb (118°Ls), MINAMI (Mn) started from LCM=111°W and observed up until LCM=130°W: the southern limb was largely whitish; since the tilt was already down to 9°N, this must be a part of the south polar hood (sph). The area of Solis L was well dark, and the region from Xanthe to Tharsis was whitish bright in the evening. The north polar cap (npc) or its surrounding was compactly white on the northern edge. The large area of Ascræs L to
On the day MURAKAMI (Mk) recorded his first observation at LCM=123°W (when app diam=7.1"): This season Mk first observed on 4 January (099°Ls) but was long annoyed by the bad seeing, and this was the first drawing made after six poor observations. Mk recorded the brightness of the sph and the dark band adjacent to it.
On 17 Feb (119°Ls), Mn observed at LCM=121°W: Xanthe was not so bright as expected.
On 18 Feb (119°Ls), Naha at Okinawa was endowed with a fine sky: HIGA (Hg) took Video images at LCM=092°W, 102°W, 111°W, 121°W, and ISHADOH (Id) made drawings at LCM=112°W, 121°W, 131°W: Id felt the evening mist at Xanthe-Tharsis thick, and separated it to two patches. M Sirenum was evident on the morning to noon side, and its south was whitish light. The npc was evident. Hg's images show well the cloud at the southern limb and the Xanthe-Tharsis white cloud, and the area of Solis L between them is dark.
On 19 Feb (120°Ls), Mn observed from LCM=063°W to LCM=111°W (every＋10°W), Hg made pictures at LCM=082°W, 092°W, 104°W, 111°W, Id obtained drawings at LCM=105°W, 114°W, and MORITA (Mo) took a CCD image at LCM=105°W. In the case of Mn, the npc was evident and the sph was whitish bright as if protruding, and the area including Auroræ S was blue black while M Acidalium was slightly faint and looked brownish. The area of Chryse and Xanthe was bright even through a JIS Orange filter (O56 implying to cut shorter waves than 560nm). At LCM=102°W it increased its brightness. Id commented at LCM=105°W that a white patch (he says Ascræs Mons ?) was disconnected from Xanthe. The npc was detected. Mo's CCD image at LCM=105°W shows also Xanthe-Tharsis clearly and shows two light patches, though it is difficult to identify them with Id's. Note these are seen in Red. Hg produced the same angles as the day before and the images show no explicit changes: At LCM=092°W, the image shows a flow of the pale mist from Chryse.
On 21 Feb (121°Ls), Hg took Video at LCM=053°W, 073°W, 083°W, 092°W, Id watched at LCM=076°W, 085°W, 095°W, and Mk observed at LCM=078°W. Id recorded that an evening mist was pushed out from Chryse to Tharsis. The sph was dull. M Acidalium was rather obscure. Mk observed that the sph blue-whitish, and the npc was white while Xanthe was not prominent. Hg's images become good from LCM=073°W, and at around LCM=083°W, the s-limb and Xanthe are light.
On 22 Feb (121°Ls), we made key observations: Taking account of the MORITA
observations on 20 February, T NAKAJIMA (Nj) and Mn, paying attention to M Acidalium and Chryse,
observed from LCM=034°W to LCM=083°W: The seeing turned better, and M Acidalium
was well dark. At LCM=044°W, it looked normal but less dark than the area of M Erythræm. Mn recorded that
Mn discussed about these images by emails with Mk, Mo, Id and Ns, and, though we are
not yet conclusive, we tentatively consider that the three spots must the
condensed ones from the areas corresponding to
During the Japanese period, WASIUTA (MWs) observed on 18 Feb (120°Ls) at LCM=306°W, 316°W
where Syrtis Mj was dark evident and
On 27 Feb (123°Ls), Hg chose the angles at LCM=357°W, 006°W, 016°W, 025°W where Chryse-Xanthe-(Tharsis) is very whitish bright near the f limb. As the planet rotates, the mist seems to remain near the limb. Note that the polarisation effect causes the limb mist lighter when the phase angle is near 30°, and so it's incomparable with cases in 1999.
During the above period, MWs
observed on 24 Feb (122°Ls) at LCM=278°W: Syrtis Mj was near the CM and
1 ~ 15 March 2001
Mar (124°Ls), MWs drew at LCM=211°W,
220°W in which the morning
DPk made an instructive series of images on the day
At LCM=186°W, Elysium Mons (at longitude =211°W) is just 13°after the noon (at 0:50 pm) since the phase angle is 38° but is still not so cloudy but after 80 and 126 minutes later the round area becomes very white. Syrtis Mj shows an omen at LCM=209°W, and presents its blue aspect at LCM=223°W. The original sph is duller than
On 2 March (125°Ls), Hellas came into sight from
On 4 Mar (126°Ls), DPk produced images at LCM=197°W : Elysium is white at about 1:40 pm LMT. Hg described Hellas blue whitish on 5 Mar (126°Ls) at LCM=299°W;
On 6 Mar, HERNANDEZ (CHr) observed earlier at around LCM=175°W: Cerberus was evident, and Phlegra was caught dark but narrow. The dark band along Gyndes was broad that bounded the npc on the limb.
On 8 Mar (127°Ls), PEACH (DPc) observed at LCM=066°W (at 4:50 GMT) where M Acidalium and the southern markings were dark (while Solis L was faint), and the area of Chryse to Xanthe was bright. He also detected the sph as well as the npc. A light patch near the f limb. Partially used Wr#21. In Japan, Mo took CCD images at LCM=288°W, 298°W in which Hellas is bright in G and B while weak in R perhaps due to the poor seeing.
On 9 Mar (128°Ls), Id started from 21:00 GMT and observed at LCM=293°W, 307°W where
On 10 Mar (128°Ls), MWs observed at LCM=118°W (at 9:40 GMT) where Tharsis was bright near the evening terminator. In
At Fukui, Mn observed at LCM=266°W, 276°W, 286°W: The images were stable and Hellas was conspicuous and showed a clear boundary in general; at LCM=276°W however the preceding part was sharply brighter while the following area looked slightly duller and the boundary was blurred: First Elysium was a bit seen at the Sunset p terminator, and Utopia-Casius was evident in the north. The npr is whitish light. Then
On 12 Mar (129°Ls), MWs observed at LCM=103°W and detected the Tharsis evening cloud. AKUTSU (Ak) took CCD pictures at LCM=256°W: the pale
On 13 Mar (130°Ls), at the Fukui City Observatory, the CMO Fukui Trio NAKAJIMA (Nj), NISHITA (Ns) and Mn gathered: Nj & Mn observed from LCM=199°W to LCM=262°W: From around LCM=205°W, the sph became very brighter. At LCM=218°
Ns tried on the day to equip the 20 cm refractor with
his new cooled
Different place at
On 14 Mar (131°Ls), the sky over
On 15 Mar (131°Ls), Mn observed from LCM=180°W to LCM=248°W where Elysium appeared near noon and moved to the evening side. Phlegra-Cerberus was rather dark evident as in 1999, and from LCM=199°W the Ætheria dark patch came into sight. The sph was pale but not so brilliant until then, while from around LCM=218°W the
On the same day, Mo observed
On the morning, Ns also obtained another image at LCM=234°W: Elysium and Cebrenia are light visible.
A few comments are in order:
1) Under the present angular diameter Hellas usually appears uniformly whitish brilliant, but we should remember that Hellas in 1999 when the planet was nearly at opposition was at same season as this time and showed a not-so-simple structure inside its basin (as observed in Japan on 29 Apr (131°Ls) or 30 Apr (132°Ls) 1999).
2) We should also remember that different apparent diameters (or resolutions) give different images to a light/bright area of the same dimension: The Elysium-Mons cloud on DPk's images on 1 Mar 2001(124°Ls, app diam=7.8") should be considered to have behaved as the one on DPk's images taken on 24 Apr 1999 (129°Ls, app diam=16.0") cited in CMO #123 p2766.
3) It is usually said the CCD technology opened a way to an observation of the details even when the apparent diameter is not enough, but we should remember that any enhanced CCD images depend so much on the processing that we should judge the ghost-like markings, light or dark, from various angles; especially the visual observations should finally be referred to when any assertion is made. By the same token, the filtered work is not any final means: Every image, if visual, should be synthesised.
EXT issue shall review the observations made during a one-month period from 16 March to 15 April 2001. Note that 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 email@example.com as well as to firstname.lastname@example.org. 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 email@example.com ) .