2001 Mars Observation Reports -- #05, Revised --

OAA MARS SECTION

Mars Observations

made during the period
from16 February 2001 (118Ls) to 15 March 2001 (131Ls)
based on the article published in CMO #241 (25 March 2001)

 


by Masatsugu MINAMI, Director of the OAA Mars Section



 

T

he present report deals with the Mars observations made during the period from 16 February 2001 (118Ls) to 15 March 2001 (131Ls) during which the apparent angular diameter went up from 7.0" to 8.8", the tilt changed from 9N down to 4N, and the planet was on the maximal wane with the phase angle 38. The apparent declination was down to -22 at the end.
  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 131Ls 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.


T

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 -3C in the early morning, while on 15 Mar it was rather warm with 4C outside of the dome. On 19 Mar it went up to 9C at midnight.

 

This time we acknowledge receipt of 147 observations from the following 13 observers:

 

AKUTSU, Tomio (Ak) Karasuyama, Tochigi, Japan

1 Sets of CCD Images (12 March 2001)

f/60 32cm spec equipped with a Teleris 2

 

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

1 Set of Drawings (6 March 2001)

410, 470x 20cm SCT

 

HIGA, Yasunobu (Hg) Naha, Okinawa, Japan

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) Naha, Okinawa, Japan

12 Drawings (18, 19, 21 February; 9, 14 March 2001)

400, 530x 31cm speculum

 

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

1 CCD Image (19 February 2001)

20cm SCT equipped with a Starlight Xpress MX-5

 

MINAMI, Masatsugu(Mn) Fukui, Japan

53 Drawings

(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, Hiroshima, Japan

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) Fujisawa, Kanagawa, Japan

8 Drawings (16, 18, 21, 22, 26 February; 13 March 2001)

320,425x 20cm speculum

 

NAKAJIMA, Takashi (Nj) Fukui, Japan

7 Drawings (22 February; 13 March 2001)

375,400x 20cm refractor *

 

NISHITA, Akinori (Ns) Fukui, Japan

3 CCD Images (13, 15 March 2001)

f/190 20cm refr* equipped with an Apogge AP7p

 

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

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, Norfolk, UK

1 Drawing (8 March 2001) 405x 31cm Meade SCT

 

WASIUTA, Myron E(MWs) VA, USA

10 Drawings (18, 24, 27 February; 1, 10, 12 March 2001)

360x 31cm speculum/360,440x 16cm refractor

 

* Fukui City Observatory

 Observation   :


 16 ~ 28 February 2001

W

E, on the Japanese side, observed densely for 7 days from 16 February (118Ls) to 22 February (121Ls) the region from LCM=034W to LCM=130W: during which 55 numbers of observations were recorded.
  On 16 Feb (118Ls), MINAMI (
Mn) started from LCM=111W and observed up until LCM=130W: the southern limb was largely whitish; since the tilt was already down to 9N, 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 Ascrs L to Arcadia was densely reddish westward from Nilokeras. At LCM=121W, Argyre seemed to show up.
  On the day MURAKAMI (
Mk) recorded his first observation at LCM=123W (when app diam=7.1"): This season Mk first observed on 4 January (099Ls) 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 (119Ls),
Mn observed at LCM=121W: Xanthe was not so bright as expected.
  On 18 Feb (119Ls), Naha at Okinawa was endowed with a fine sky: HIGA (
Hg) took Video images at LCM=092W, 102W, 111W, 121W, and ISHADOH (Id) made drawings at LCM=112W, 121W, 131W: 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 (120Ls),
Mn observed from LCM=063W to LCM=111W (every10W), Hg made pictures at LCM=082W, 092W, 104W, 111W, Id obtained drawings at LCM=105W, 114W, and MORITA (Mo) took a CCD image at LCM=105W. In the case of Mn, the npc was evident and the sph was whitish bright as if protruding, and the area including Auror 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=102W it increased its brightness. Id commented at LCM=105W that a white patch (he says Ascrs Mons ?) was disconnected from Xanthe. The npc was detected. Mo's CCD image at LCM=105W 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=092W, the image shows a flow of the pale mist from Chryse.

  On 20 Feb (120Ls), Mn observed from LCM=053W to LCM=102W: Seeing being poor, M Acidalium looked quite faint compared with the area of M Erythrm and Auror S. Chryse-Xanthe was whitish bright, but unstable. At LCM=092W, Xanthe was white near the terminator. On the day, Mo produced images at LCM=091W and 095W: Here also are shown two light spots inside Xanthe and the following area. In R, the light areas are strangely more prominent than the dark markings.
 On 21 Feb (121Ls),
Hg took Video at LCM=053W, 073W, 083W, 092W, Id watched at LCM=076W, 085W, 095W, and Mk observed at LCM=078W. 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=073W, and at around LCM=083W, the s-limb and Xanthe are light.

  On 22 Feb (121Ls), 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=034W to LCM=083W: The seeing turned better, and M Acidalium was well dark. At LCM=044W, it looked normal but less dark than the area of M Erythrm. Mn recorded that Tempe was pinkish free from mist. To the east of Chryse, a brighter core seemed to exist though there was no brighter area inside the disk at LCM=034W. At LCM=054W, an ebm was seen from the evening Chryse to the morning Tharsis (thru R60, O56, G), Tharsis being slightly off-white. At LCM=063W onward, M Acidalium became faded in a tint of brown and the following region looked largely densely reddish. The sph was roundish definite, but its inside was not uniform in intensity. At LCM=073W, Chryse-Xanthe was quite white but not so bright. Mk observed at LCM=056W & 066W: M Acidalium was weaker than the area of M Erythrm, and much weaker in the latter. He observed the Chryse mist did not creep up. The sph was blue- whitish.

  The CCD images on the day by Mo are also interesting: He produced them at LCM=070W, 075W, 080W one set of which was uploaded on the CMO Web-Site: The Chryse matter in R and G is made of a series of light stains like a furrow, and the images at LCM=080W show three light spots there. In B the sph and Xanthe are light.

  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 Tempe, Ophir and Xanthe. Out of these, Tempe does not appear in B implying that Tempe is free from the whitish mist or cloud. On the contrary, Ophir must have been full of cloud/mist, and finally Xanthe must be covered also by a white cloud/mist. It is difficult to detect any dust cloud inside the light deserts like Chryse, but this time at most we consider that Chryse was thickly covered by a dense white cloud mixed with the airborne dust. Note that every bright area in R does not correspond to the dust cloud, and we hope nobody believe Tempe is dust cloudy because it is light in R while dark in B. According to Id, Chryse was white or light grey on 21 February. The phenomenon that Chryse is whitish bright in the afternoon is quite a common one usually observed there, and in 1999 at the same season, we often observed bright cores inside Chryse and Xanthe (eg; on 16 Apr 1999 (125Ls) at LCM=048W and 21 Apr 1999 (127Ls) at LCM=044W etc). Cf the description in CMO #215. As to the Thaumasia sph at the same season noted by Mk, see CMO #216.

  During the Japanese period, WASIUTA (MWs) observed on 18 Feb (120Ls) at LCM=306W, 316W where Syrtis Mj was dark evident and Hellas appeared brilliant. He also detected the npc on the N edge (#240 LtE). On 19 Feb (119Ls), MELILLO (FMl) obtained a Wr#25 image at LCM=313W in which Syrtis Mj and a northern marking are present while Hellas is not described.

  In Japan, the sky recovered on 26 Feb (123Ls): Mn observed from LCM=346W (every+10W) to LCM=047W. In the first half, the seeing was preferable (-2C outside), and from the outset at 17:40 GMT S Sabs and M Acidalium were definitely seen, and though Hellas had already sunk, the sph sharply whitish, visible also thru R60 (a JIS filter cutting shorter waves than 600 nm). Chryse looked whitish bright at the f limb, and the mist remained near the limb and was gradually weakened. In the latter, Chryse was inside the disk, but no bright core inside. The npc was flat but quite evident. Mk also observed on the day at LCM=028W, 037W where a faint white area near the preceding terminator came up to Chryse. M Acidalium was less dark than the dark area on the southern hemisphere. Tempe was slightly light. Mo secured images at LCM=029W, 037W, 041W: In R, the dark markings in the south are prominent, M Acidalium is shown up and a light furrow is seen in Chryse in R as well as in G (not so conspicuous in B).
  On 27 Feb (123Ls),
Hg chose the angles at LCM=357W, 006W, 016W, 025W 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 (122Ls) at LCM=278W: Syrtis Mj was near the CM and Hellas was brilliant. This was made in twilight at 11:30GMT in VA. On 27 Feb (123Ls), MWs also observed at LCM=235W, and at 245W: By the use of Wr#80A, Elysium was roundish light bounded the following side by the theria dark patch. Inside the sph, the morning side was brighter, maybe the morning-to-noon Hellas. On the same day 27 Feb (123Ls), PARKER (DPk) took CCD pictures at LCM=236W and at 247W where Elysium was roundish light in R as well as in B. Hellas is whitish bright near the f limb though the rest of the sph is rather dull. Syrtis Mj looks bluish though the phase angle was large. Hesperia is clearly cut. Cebrenia is lighter. Utopia definite. Blurred around the npc.

 

 1 ~ 15 March 2001

 

O

n 1 Mar (124Ls), MWs drew at LCM=211W, 220W in which the morning Hellas was checked.

  DPk made an instructive series of images on the day at LCM=186W, 209W, 223W: The description is superb and equal in quality to the previous images on 27 Feb, but the series show how Elysium becomes whitish cloudy just deep in the afternoon, and how Syrtis Mj and Hellas appear from the f limb.
  At LCM=186W, Elysium Mons (at longitude =211W) is just 13after 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=209W, and presents its blue aspect at LCM=223W. The original sph is duller than Hellas. To the north of Utopia, the npr is flatly light also in R. The R images show clearly Propontis I as well as the dark band made of Phlegra and Cerberus quite in the same forms as we observed in 1999. Phlegra is as well broad and brownish (or densely reddish).

  On 2 March (125Ls), Hellas came into sight from Japan. Mn observed from LCM=317W to LCM=006W: Hellas remained a bit when LCM=337W, and disappeared by the time of LCM=346W while the sph instead became very thick. The morning mist at Chryse became thicker, and might be connected with the evening mist at ria. M Acidalium was normal and gradually darker. The npc was evident. Hg obtained images at LCM=331W and 341W: Chryse is not yet morning bright within this range.
  On 4 Mar (126Ls),
DPk produced images at LCM=197W : Elysium is white at about 1:40 pm LMT. Hg described Hellas blue whitish on 5 Mar (126Ls) at LCM=299W; S Sabs is shot. Hg further secured images on 6 Mar (127Ls) from LCM=272W (at 17:40 GMT) to LCM=328W (at 21:29 GMT) every 40 minutes. Hellas gradually sank and Chryse became whiter along the f limb.
  On 6 Mar, HERNANDEZ (
CHr) observed earlier at around LCM=175W: 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 (127Ls), PEACH (
DPc) observed at LCM=066W (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=288W, 298W in which Hellas is bright in G and B while weak in R perhaps due to the poor seeing.
 On 9 Mar (128Ls),
Id started from 21:00 GMT and observed at LCM=293W, 307W where Hellas was brilliant. In the former, Libya looked light and in the latter S Sabs was detected.
  On 10 Mar (128Ls),
MWs observed at LCM=118W (at 9:40 GMT) where Tharsis was bright near the evening terminator. In Japan, Mo obtained images at LCM=279W & 284W: Syrtis Mj is near at the CM, and Hellas is brighter in the order of B, G and R.

  On 11 Mar (129Ls), Mo took CCD sets of images at LCM=262W, 269W and 273W: The first set is good, and the morning Hellas is bright in R also. In R, Cebrenia is light and the shadowy spot at Utopia is visible. Elysium, light in B, appears white in the colour composite.
  At Fukui,
Mn observed at LCM=266W, 276W, 286W: The images were stable and Hellas was conspicuous and showed a clear boundary in general; at LCM=276W 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 S Sabs became obvious.
 On 12 Mar (129Ls),
MWs observed at LCM=103W and detected the Tharsis evening cloud. AKUTSU (Ak) took CCD pictures at LCM=256W: the pale Hellas is shown, but the presence of Syrtis Mj is unknown.
  On 13 Mar (130Ls), at the Fukui City Observatory, the CMO Fukui Trio NAKAJIMA (
Nj), NISHITA (Ns) and Mn gathered: Nj & Mn observed from LCM=199W to LCM=262W: From around LCM=205W, the sph became very brighter. At LCM=218W Hellas was shown to shine on the f limb while Syrtis Major was not detected (because of the tiny angular diameter): Elysium was one-point ighter bounded east by a dark band of Phlegra-Cerberus. The theria dark patch was also quite evident. Cebrenia was a bit light. The morning part of Utopia was hazy. At LCM=228W, Syrtis Mj was quite obvious. At LCM=238W, the morning-to-noon Hellas looked brighter than the rest of the pale sph. There was seen a shadowy broad faint band from M Cimmerium to theria. At LCM=252W, Hellas now prevailed on the southern hemisphere. The white Elysium was then on the p limb.

  Ns tried on the day to equip the 20 cm refractor with his new cooled CCD camera. He did not use any filter to produce the images at LCM=248W, 259W. The processed images show Elysium and Cebrenia to be lighter, pinching the theria dark patch. Hesperia seems to be shown. Hellas' image may be identical with a could-be Red Hellas.
  Different place at Fujisawa,
Mk observed simultaneously at LCM=199W, 208W; exactly the angles taken by DPk on 1 and 4 March.
  On 14 Mar (131Ls), the sky over Naha was clear, but
Id overslept and only observed at LCM=250W, 260W: Hellas was round and whitish bright, Elysium was roundish bright near the Sunset terminator and the top of Utopia was clearly seen. The npc was faint and obscure.
  On 15 Mar (131Ls),
Mn observed from LCM=180W to LCM=248W where Elysium appeared near noon and moved to the evening side. Phlegra-Cerberus was rather dark evident as in 1999, and from LCM=199W the theria dark patch came into sight. The sph was pale but not so brilliant until then, while from around LCM=218W the Hellas effect stood out. The npc was dim but evident. At LCM=238W a shadowy broad band faintly looked to go down from M Cimmerium to theria.

  On the same day, Mo observed at LCM=230W ~ 237W and obtained a good set at LCM=233W: In R Elysium and Cebrenia are equally light, but in G and B Elysium more prevails, so that Elysium is whiter. The theria dark patch is evident and looks connected with the spike of M Cimmerium. In B, the f side is lighter, so that the morning Syrtis Mj appears blue in the composite. Hellas is whitish bright, while the preceding sph is not white.
 On the morning,
Ns also obtained another image at LCM=234W: Elysium and Cebrenia are light visible. Libya is also a bit lighter preceding Syrtis Mj. Unfiltered yet.

  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 (131Ls) or 30 Apr (132Ls) 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(124Ls, app diam=7.8") should be considered to have behaved as the one on DPk's images taken on 24 Apr 1999 (129Ls, 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.


N

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 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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