2001 Mars Observation Reports -- #13--
OAA MARS SECTION
Mars Observations
in the Second Half of July 2001
from 16 July 2001 (196°Ls) to 31 July 2001 (205°Ls)
based on the article published in CMO #249 (10 August 2001)
by Masatsugu
MINAMI, Director of the OAA Mars Section
T |
HE global yellow cloud
stays longer than expected (while the
THIS time we received still a lot of observations from
the following observers:
AKUTSU, Tomio (Ak)
6 Sets of CCD Images (16, 20, 27,
30 July 2001) f/70 32cm spec with a Teleris
2
ASADA, Tadashi (As) Munakata,
5 Sets of CCD Images (21, 23, 27
July 2001) 30cm
spec equipped with a Lynxx PC
BIVER, Nicolas (NBv)
10 Colour Drawings (12, 14, 16, 20,
21, 24, 28, 30 July 2001)
330x 26cm
speculum/300x 20cm speculum
CAVE, Thomas R (TCv)
4 Drawings (14, 18, 19, 27 July
2001) 400x 33cm speculum
Di SCIULLO,
Maurizio (MSc)
1 Set of CCD Images (31 July 2001) 25cm Excelsior Optics E-258
FALSARELLA, Nélson (NFl)
1 CCD Image (25 July 2001) 20cm speculum + AVA ASTROVID 400
GRAFTON, Edward A (EGf)
2 Sets of CCD Images (28, 31 July
2001) f/60 35cm
HEATH, Alan W (AHt) Long Eaton,
2 Drawings (12, 13, 14, 19, 23, 27,
30 July 2001) 160,
200x 20cm SCT
HIKI, Toshiaki (Hk)
18 Drawings (20#, 21##, 23, 24,
30 July 2001)
430x 22cm speculum
420x 25cm SCT,
430x 35cm SCT, 480x 40cm spec (chez WAKUGAWA)#
420x 25cm SCT,
330x 21cm spec, 400x 31cm spec (chez ISHADOH)##
ISHADOH, Hiroshi (Id)
7 Drawings (16, 23, 26, 27, 31 July
2001) 290, 340, 400x 31cm speculum
ISHIBASHI, Tsutomu (Is)
2 Colour Images (16 July 2001) 31cm f/6.4 spec, Fujichrome
400F
KUMAMORI, Teruaki (Km)
5 CCD Colour Images (19‡, 20, 23,
29July 2001)
20cm Dall
Kirkham with a Sony PC-5 / 60cm Cassegarain‡ with a
Sony TRV-900
MELILLO, Frank J (FMl)
1 CCD Image (21 July 2001) 20cm SCT with a Starlight Xpress MX5
MINAMI, Masatsugu (Mn)
96 Drawings (16~19, 20#, 21#, 22**, 23~31
July 2001)
420, 530x 25cm
spec
420x 25cm SCT,
480x 40cm spec (chez WAKUGAWA)#
480, 600x 40cm
spec (chez Isao MIYAZAKI)**
MOORE, David M (DMr)
3 Sets of CCD Images (18, 22, 27
July 2001) f/40 36cm Cass with an Astrovid
2000 video camera
MORITA, Yukio (Mo)
23 Sets of CCD Images (15, 20**, 21**, 22, 24,
25, 26, 27 July 2001)
35cm SCT** / f/50 25cm speculum
equipped with an ST-5C
MURAKAMI, Masami (Mk) Kanagawa /
17 Drawings (16, 20#, 21##, 23, 30
July 2001)
320, 400x 20cm
speculum
420x 25cm SCT,
430x 35cm SCT, 480x 40cm spec (chez WAKUGAWA)#
420x 25cm SCT,
330x 21cm spec, 400x 31cm spec (chez ISHADOH)##
NAKAJIMA, Takashi (Nj)
25 Drawings (19, 22, 23, 25, 26, 28
July 2001) 400x 20cm refractor*
NARITA, Hiroshi (Nr)
9 Drawings (16, 20, 23, 24, 30 July 2001) 320,400x 20cm refractor
NISHITA, Akinori (Ns)
6 CCD Colour Images (20#, 25, 26 July 2001)
35cm SCT #
f/190 20cm refractor*equipped
with an Apogge AP7p
PARKER, Donald C (DPk)
5 Sets of CCD Images (18, 30, 31
July 2001) f/36 41cm Newtonian equipped with a Lynxx PC
TAN, Wei-Leong (WTn)
17 Sets of CCD Images (17, 18, 21,
23, 24, 29, 30 July 2001) f/16 28cm SCT equipped with an ST-7E
TEICHERT, Gérard (GTc)
3 Drawings (21, 22, 25 July 2001) 330, 310x 28cm
Schmidt-Cassegrain
TSUNEMACHI, Hitomi (Ts)
80 Drawings (20#, 21##, 22**, 23~31
July 2001)
420, 530x 25cm
speculum
420x 25cm SCT, 430x
35cm SCT, 480x 40cm spec (chez WAKUGAWA)#
420x 25cm SCT, 330x
21cm spec, 400x 31cm spec (chez ISHADOH)##
480, 600x 40cm spec
(chez
VALIMBERTI, Maurice (MVl) Victoria,
1 Set of CCD Images (24 July 2001) f/80 15cm refractor with a TC245 based camera
‡
*
The Yellow Cloud :
The yellow cloud thickly covers the whole of the Martian surface (except for
the polar regions), and at present there is no sign of
subsiding. On 31 July, 38 days had passed since the first dust burst occurred.
We write so as 31 July (38 days).
Receiving a phone call from DOBBINS (TDb) about the occurrence of the dust storm, HEATH (AHt) however thought M
Cimmerium and M Sirenum were still visible on 14 July
(21 days) at ω=201°W, and 19 July (26 days) at ω=176°W. Note that
because of the veiling by the storm even KUMAMORI (km)'s
image by a 60cm Cass on 19 July does not show any particular dark markings at ω=020°W.
This implies that the deformed part corresponding to the western part of M
Cimmerium darkened since 3 July (10 days) (see MORITA's images at p3071 of #248) still remained dark (veiled of
course by the global yellow cloud). MOORE (DMr)
produced images on 27 July (34 days) at ω=225°W where the patch still shows up.
In mid-July, there were observed in
Activity of the North Polar Hood :
The north polar hood (nph) has been very active
(since 2 July?), and for example for several days 13 July (20 days)~15 July (22
days) it was observed here that the portion of the nph to
the north of Ascræus Mons looked bulged up. On 16
July (23 days) the brim-side of the nph
following M Acidalium was very bright. Particularly on 17 July (197°Ls, 27
days) we observed an extraordinarily bright oval on the brim; to the extent
that we have never seen such a brightness: At ω=055°W, Mn in Okinawa noticed at the morning side of the nph a brighter spot while it came up near the CM at around ω=094°W,
though it was less brighter then. It was however very conspicuous around ω=074°W:
the bright matter looked as if spouting out from the nph to the SW direction so that the border of the nph showed a gap there. On the night after observation, HIGA (Hg) visited Mn's observing place
(quite near his place) and told that he had also noticed the bright oval on the
Video monitor and assured it was very white because it was also seen bright
through the blue light on the 3ccd Video monitor. WTn in
In response to the activity, the area to the east of M Acidalium was variable:
On 21 July (28 days), Mk (chez ISHADOH) and Mn (chez WAKAGAWA) observed by coincidence at ω=021°W
and noticed that the area between Deuteronilus and
the dark border of the nph was rather light (km's image on 19 July at ω=020°W and ASADA (As)'s R images on 21 July at ω=010°W already showed Deuteronilus faintly). On 22 July (29 days) Ts and Mn (with Id and Hg) visited Isao MIYAZAKI's observatory (at Gushikawa, Okinawa) and used his
40 cm Newtonian to observe the area: there was some dusty streams in the desert
and the area showed a complex as if another faint dark marking existed to the
east of M Acidalium.
The nph itself was considered normally thick or thin: The
northern part of M Acidalium was seen through the nph
several times on 20 July at ω=025°W (by Mn), on
21 July (200°Ls) at ω=035°W (by Hk), ω=036°W (by Mn), on
23 July at ω=035°W (by Mn), and on 24 July at ω=035°W
(by Mn), ω=040°W (by Ts):
Such a shadowy segment was often observed inside the nph.
The nph continued to be active: On 28 July (35 days) the
morning patch to the north of M Acidalium was intense. The nph looked also complex on 30 July (37 days) and 31 July (38
days); on 30 July at ω=310°W a portion to the NW of Utopia showed a
shadowy area inside, and on 31 July, ISHADOH (Id)
observed at ω=282°W that the nph was subdued with a
shadowy segment inside. From the opposite side seen from the
Finally we note that the band adjacent to the perimeter of the nph was quite dark this period in general as if the dust cloud
avoided the water-vapour barrier of the north
circumpolar region. See the dark fringe of the nph in
any of B and G images in the case of the ccd images.
Tharsis Ridges and Olympus
From the Orient, Olympus Mons and Tharsis Montes
faced to us as interesting dark spots in mid-July. On 16 July (23 days),
Olympus Mons was first clearly witnessed by Mn at ω=084°W
(one Martian hour after
Noachis :
We finally note that Depressiones Hellesponticæ became visible from 24 July; it showed a dark
blue (not veiled) tint adjacent to the spc and
its morning cloud.
The South Polar Cap and Its Morning Cloud :
The south polar cap (spc) was thin at the
southern limb, and followed by a thick persistent morning cloud: The cloud
stayed always on the limb often with a sharp and dark boundary, and so it was
often confused with the spc. At around 200°Ls, the
snow line of the spc is usually at
58°S~60°S if seen from around 000°W , and at around ~62°S from the opposite
180°W. Hence if the central latitude is 7°N, we can expect a thicker spc on the southern limb, and so it is possible for the spc to have shrunk much faster. The morning cloud, apparently
made of water vapour, looks also out of usual season:
At the same season in 1986 (a round 5 July 1986) such a cloud was seldom
observed, and as well it was not conspicuous in 1969 (around 1 August 1969).
End of July :
In
ERRATA : We are sorry for the mistakes in the list at
page 3068: The dates of observations by Don BATES should be read 8, 9 July and
those by Nicolas BIVER should be 12, 14 July.
T |
he next issue (#250)
shall review the observations during a fortnight period from 1 August (206°Ls)
to 15 August 2001 (214°Ls). CMO #251 shall be published on 25 September 2001.
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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