2001 Mars Observation Reports -- #12--
OAA MARS SECTION
Mars Observations
in the First Half of July 2001
from 1 July 2001 (188°Ls) to 15 July 2001 (196°Ls)
based on the article published in CMO #248 (25 July 2001)
by Masatsugu
MINAMI, Director of the OAA Mars Section
HE planet now suffering
from an out-of-season dust cloud showed the apparent
diameter of 20.5 arcsecs on 1
July (188°Ls) while it went down to 19.2 arcsecs on
15 July (196°Ls). Usually a detailed image is expected on such an occasion, but
this time a global observation was needed. The central latitude went up from
6.1°N to 7.3°N, and the phase angle was 15° to 26°. The surface might loose the
meaning of its season because of the rapid development of the yellow cloud, but
the nph was active in accordance with the season. The trend
of the spc was also interesting.
We acknowledge receipt of the observations this period
as follows:
AKUTSU,
Tomio (Ak) Tochigi,
Japan
4 Sets of CCD Images (4, 10, 15
July 2001) f/70
32cm spec with a Teleris 2
ASADA,
Tadashi (As) Munakata, Fukuoka, Japan
12 Sets of CCD Images (1, 2, 4, 8
July 2001) 30cm
spec equipped with a Lynxx PC
BARNETT,
John H (JBn) VA, USA
2 Drawings (1, 11 July 2001) 270, 360x 18cm refractor$
BATES,
Donald R (DBt) Mt
Locke/Houston, TX, USA
2 Colour Images (8, 9 July 2001) f/120 25cm
speculum, Elite Chrome 200
BIVER,
Nicolas (NBv) Versailles,
France / Noordwijk, Netherlands!
2 Colour Drawing (12!, 14 July 2001)
190x 20cm speculum! / 330x
26cm speculum
CAVE,
Thomas R (TCv) Long Beach, CA,
USA
2 Drawings (2, 5 July 2001) 390, 400, 550x 33cm speculum
CIDADÃO,
António José (ACd) Oeiras, Portugal
6 Sets of CCD Images (4/5, 6 July 2001) 25cm LX200SCT with
an ST-5C + AO
FALSARELLA,
Nélson (NFl) Sao Jose do Rio Preto - SP, Brasil
9 CCD Images (6, 9, 10 July
2001) 20cm speculum + AVA ASTROVID 400
GRAFTON,
Edward A (EGf) Houston,
TX, USA
3 Sets of CCD Images (5, 7, 11 July
2001) f/60 35cm
Celestron
SC with an ST6
HEATH,
Alan W (AHt) Nottingham, UK
3 Drawings (1, 3, 4 July 2001) 200x 20cm SCT
HIGA,
Yasunobu (Hg) Naha, Okinawa, Japan
38 Video Images (1, 2, 3, 6~10, 12,
13, 14 July 2001)
25cm f/6.7
speculum equipped with a Sony VX-900
HIKI,
Toshiaki (Hk)
Minowa, Nagano, Japan
14 Drawings (1, 3, 4, 10, 11, 14, 15
July 2001) 430x 22cm speculum
ISHADOH,
Hiroshi (Id) Naha, Okinawa, Japan
19 Drawings (1, 2, 6, 7, 8, 9+, 10+, 11, 12,
13, 15 July 2001)
340, 400x 31cm
speculum/420x 25cm speculum+
ISHIBASHI,
Tsutomu (Is) Sagamihara,
Kanagawa, Japan
7 Colour Images (26, 27, 28 June;
1; 3, 8, 10 July 2001) 31cm f/6.4 spec, Fujichrome
400F
KUMAMORI,
Teruaki (Km) Sakai,
Osaka, Japan
5 CCD Colour Images (2, 3‡, 10, 13‡ July
2001)
20cm Dall
Kirkham with a Sony PC-5 / 60cm Cassegarain‡ with a
Sony TRV-900
MELILLO,
Frank J (FMl) Holtsville, NY, USA
10 Sets of CCD Images (3, 7, 10, 13
July 2001) 20cm SCT with a Starlight Xpress MX5
MINAMI,
Masatsugu (Mn) Fukui* / Naha,
Okinawa, Japan
82 Drawings (1*~4*, 7*, 8 ~10,
11†, 12~15
July 2001)
400x 20cm refra* / 420,
530x 25cm spec/ 400x
31cm speculum chez ISHADOH†
MOORE, David M (DMr) Phoenix,
AZ, USA
7 Sets of CCD Images (8, 9, 11, 15
July 2001) f/40 36cm Cass with an Astrovid 2000 video
camera
MORITA,
Yukio (Mo) Hatsuka-ichi, Hiroshima, Japan
15 Sets of CCD Images (1~4, 7, 9, 10
July 2001) f/50 25cm speculum equipped with an ST-5C
MURAKAMI,
Masami (Mk) Fujisawa, Kanagawa, Japan
33 Drawings (1~5, 8~11, 13, 15 July
2001) 320, 400x 20cm speculum
NAKAJIMA,
Takashi (Nj) Fukui, Japan
35 Drawings (2, 3, 4, 7, 9, 14, 15
July 2001) 400x 20cm refractor*
NARITA,
Hiroshi (Nr) Kawasaki,
Kanagawa, Japan
15 Drawings (2~5, 8, 9, 10, 13 July 2001) 320,400x
20cm refractor
NISHITA,
Akinori (Ns) Fukui, Japan
1 CCD Colour Image (4 July 2001) f/190 20cm refr*equipped
with an Apogge AP7p
PARKER,
Donald C (DPk) Miami,
FL, USA
11 Sets of CCD Images (3, 5, 6, 7,
9, 13# July 2001)
f/36,44 41cm Meade SCT/ f/39 41cm Newtonian# equipped
with a Lynxx PC
PARKER,
Timothy J (TPk) CA, USA
1 Set of CCD Images (1 July 2001) 31cm Cass with a 3
CCD Cam
PEACH,
Damian A (DPc) King's Lynn, Norfolk,
UK
1 Set of CCD Images (2 July 2001) f/21 31cm Meade SCT
with an ST-5C
1 Colour Drawing (3 July 2001) 405x 31cm Meade SCT
SCHMUDE,
Richard W, Jr (RSc) GA, USA
1 Drawing (15 July 2001) 240x
10cm refractor
SCHULZ,
Robert (RSz) Wien, Osterreich
2 Sets of CCD Images (4&, 14 July
2001)
30cm Clark refraktor& /20cm Meade
SCT with Webcam Philips
TAN,
Wei-Leong (WTn) Singapore
29 Sets of CCD Images (1, 2, 6, 8,
9, 10, 12~15 July 2001)
f/16 28cm SCT equipped with an ST-7E
TEICHERT,
Gérard (GTc) Hattstatt, France
1 Drawing (3 July 2001) 330, 310x 28cm Schmidt-Cassegrain
TSUNEMACHI, Hitomi (Ts) Yokohama,
Japan
8 Drawings (1, 14 July 2001) 360x 12.5cm Fluolite
refractor
VALIMBERTI,
Maurice (MVl) Viewbank,
Victoria, Australia
12 CCD Colour Images (4, 9, 13 July
2001) f/80 15cm
refra with a TC245 based camera
WAKUGAWA,
Tetsuo (Wk) Kochinda, Okinawa,
Japan
4 CCD Colour Images (1 July 2001) 40cm speculum
equipped with a Sony VX-1000
$ Richmond
Astronomical Society Ragland Observatory
‡ Sakai
City Observatory
* Fukui
City Observatory
Development of the Yellow Cloud :
1 July~3 July
(188°Ls) :
As has been noted the observers of the CMO Okinawa
were enjoying the fine skies already from 21 June, though the observers in the mainland
were still suffering from the rainy season. However on 1 July, several
observers including ASADA (As), HIKI (Hk), MORITA (Mo), MURAKAMI (Mk), TSUNEMACHI (Ts), and the present writer (Mn)
were endowed with a lull and were able to observe the surface. At Fukui, Mn started from 20:30 JST (11:30GMT at ω=189°W) and
noticed that the whole surface was covered already by the yellow cloud, and
there was still a broad vivid streak of dust cloud along Phæthontis-Electris.
At ω=199°W, though Propontis I was sighted, there was witnessed an effect
of a violent disturbance inside and near Elysium and it was apparent that the
dark patch in Ætheria was quite deformed. Strangely, there came down a dark
segment inside Elysium. WAKAGAWA (Wk)'s images at
ω=190°W~206°W, As's at
ω=198°W~224°W, Mo's at ω=204°W~243°W and HIGA (Hg)'s Video tape from ω=195°W to ω=268°W all show
these new aspects. ISHADOH (Id) started from
ω=213°W. Syrtis Mj appeared as expected, and Id
observed until ω=260°W (16:20 GMT). The deformed shape of the Ætheria dark
patch was also checked by Ts at ω=230°W. TAN (WTn) at Singapore produced images at
ω=243°W~266°W. Syrtis Mj just remains dark only at the northern part and
the eastern part of S Sabæus
looks to have been affected.
On 2 July (188°Ls), we (Nj and Mn) started from 10:50 GMT (at ω=161°W) at Fukui. Clouds floated, but
when the planet was near at the meridian, we had a nice and long break in the
clouds under a good seeing. We observed that a further disturbance had occurred
in the area of Elysium: though Propontis I was weaker, the shadowy streak
inside Elysium and the Ætheria dark patch made some differences than the day
before. There was seen a bright small disturbance to the south of the dark
patch at Ætheria . Mn's
observations were made at ω=212°W and 222°W. Km's
image at ω=211°W also shows strangely that from Phlegra
(that is dark) to Ætheria a shadowy area prevails across Elysium. As's images made at ω=188°W~230°W comprise these
features. Hg's Tape also shows this from ω=186°W to
ω=195°W. Though the dark markings, some being deformed because of dust,
were seen through, it wasapparent visually that the
whole surface (except for the circumpolar regions) had been affected by the
vast yellow cloud. The surface looked like a bright yellow glove, the faint
markings being scattered in perspective up to the limbs. The bright yellow
surface, looking pretty glossy, was attractive, and Nj and the present writer (both experienced the great yellow
clouds in 1956, 1971 and 1973) assented that we had never seen such a beautiful
surface completely/globulously covered by the bright
yellow cloud. At the same time, we concluded that the event was never local and
already it reached a new stage: It was apparent it will never easily subside
again so that it must be global. The cloud was not so thick yet, but we could
easily conclude that since its power had made the cloud to rapidly expand down
to the northern hemisphere, the cloud, though yet thin, should also have
already expanded into another hemisphere. How one can believe the present limb
of the disk should just be the end of the vivid yellow cloud that presents? We
so wrote a notice that night that the yellow cloud was already so global
that any observer in a different hemisphere should be on the alert. The quiet
invasion of the thin yellow cloud should be watched in terms of the delicate
tint of yellow, not by another standard to judge whether the dark markings
should become fainter. The frequent use of the IR range will not help to detect
a faint flow of the yellow cloud. The airborne dust should first be checked
before an arrival of any burst of dust disturbance.
On 3 July (189°Ls), we started from ω=164°W at Fukui: The dust streak at Phæthontis
looked quite active, and the following branch was bright again at the place
where the cloud on 29 June crossed M Cimmerium: It was notable on 3 July that
the western part of M Cimmerium was suddenly darkened largely. The Elysium area
was also active. The yellow cloud looked to become gradually thicker. MORITA (Mo)'s work from 1 July to 4 July is
excellent and precious: He made sets of images at the same ω angles (this
is the very method recommended by the CMO): The images show how the dust cloud
was active from day to day for example affecting the markings differently. Note
that this series is a very sequel to AKUTSU's images on 30 June (cited in #247 at p3048). KUMAMORI (Km) has the images at ω=188°W on 2 July and following 3 July.
4 July (189°Ls):
On the day there was a new movement to the east: At
Fukui, we started from 10:50 GMT (at ω=152°W), and observed until
ω=182°W that an area in Dædalia to the east of M
Sirenum was sharply bright suggesting there had been a burst of dust. VALIMBERTI (MVl) in Australia worked on the day and
made excellent images from earlier: The burst was first caught at 9:14 GMT(ω=129°W) just after the CM. More interestingly this image shows another smaller resonant
burst just to the north of Solis L. The colour images
of MVl do not show the expanding yellow cloud, but since we
shared the observation times, the morning side must have been yellow hazed and
hence the uniformity of the surfaces suggests the yellow cloud had already
reached at least the longitude of Solis L. At the following area, the western
part of M Cimmerium was further darkened as shown on Mo's images as well as on NISHITA's image at ω=225°W.
5 and 6 July (191°Ls):
GRAFTON (EGf)'s images on 5 July at ω=058°W
show
two tiny dust disturbances near Solis L, which must be
reproductions of the bright dust spot MVl
caught on 4 July. Don PARKER (DPk)'s images on the day were at
ω=033°W, and do not show the area yet, while they show the yellow dust
must have reached already as we judge from the abnormality of the area of Auroræ S. DPk employed the LRGB
method; we suppose he made up for the lost contrast.
On 6 July (191°Ls), the dust germs gave a great change: DPk's Red images at ω=048°W and 060°W show two
bright streaks; one from upper Thaumasia down to Auroræ
S and the other from Claritas down to the NE direction. These images were sent
with a quick note (cited in #247 LtE) and at the same
time he wrote a message to the present writer (cited this issue). We were of
the opinion that an earlier arrival of the yellow dust ingredients brought
about the bursts.
We were watching the planet 8 to 10 hours behind from America. Id made an important observation on 7 July that Olympus Mons
appeared as a dark spot at ω=170°W. This implies the activity of the dust
cloud was in a new stage: The depth of the cloud increased to the extent that
just the summit was uncovered while the outskirts were all thickly buried. After
that the summit (as well as those of Tharsis Montes) was observed in contrast
as a brownish spot from morning to evening. We so rewound HIGA (Hg)'s Videotape and noticed it was already spotted on 6 July
(191°Ls) but not earlier than 4 July, and so we concluded the new stage was
completed on 5 or 6 July. This corresponds timely to the burst near Solis L.
7 and 8 July
(192°Ls):
DPk's
drawing on 8 July
On 7 July (191°Ls), EGf shot at ω=020°W,
and DPk at
ω=026°W~031°W: the preceding streak looks to have been
widened. On the same day, MOORE (DMr) caught the two streak
near the centre at ω=043°W~068°W: The aspect is quite reminiscent of the
streaks of the 1973 dust cloud seen on 16 October a few days after the
outbreak. The aspect must be related with the topography of the area and the
altitude of the dust cloud stratum. On 8 July, the present writer (Mn) moved to Naha
to watch the planet and made every-day-observations since then for a month.
9 July~15 July (196°Ls):
DPk's drawings on 9 July
On 9 July (192°Ls), Don PARKER (DPk) in Florida
observed at ω=354°W and reported that S Meridiani
diminished. Two hours later MOORE (DMr) in Arizona confirmed the phenomenon at
ω=023°W/028°W. We otherwise heard on 9 July from Sam WHITBY (SWb) in Virginia that at 2h GMT Sinus Sabæus and Sinus Meridiani were unrecognizable though the
seeing was good. Almost all of M Erythræum was
buried, but its eastern end and the dark band in Noachis was recognized.
However on 11 July (193°Ls), DMr wisely shot from the same angle and proved that
the Noachis part had become fainter. The remaining isolated patch at the east
end of M Erythræum was caught a little earlier by EGf in Texas at ω=343°W. On 15 July (196°Ls), DMr's images at ω=340°W show that another
strange new band runs from the remaining patch at M Erythræum
down to the eastern part of S Sabæus crossing
Deucalionis R just like a pseudo Sabæus . On 13 July
(195°Ls), DPk made a set of good images at ω=292°W~302°W
where a lot of markings are shown to be fainter or deformed. Depressiones Hellesponticæ
however is going to show up.
On 9 July (192°Ls) DPk thus shot at ω=354°W, DBt in Texas at ω=020°W,
DMr at ω=028°W, and then came the excellent
images by MVl in Melbourne
at ω=084°W/090°W. At Naha, Okinawa, ISHADOH (Id) and
Mn used a 25cm Newtonian and observed together from
ω=110°W to ω=183°W and near them HIGA (Hg)
videotaped from ω=130°W to ω=178°W. During the Japan time, Mk
observed at ω=139°W, and Mo shot at ω=154°W,
and as well TAN (WTn) in Singapore produced images at
ω=164°W~170°W. Thus we may say we covered continuously a half sphere. On
MOORE (DMr)'s images M Acidalium is near the CM and the western
Erythræum fades and on MVl's, M
Acidalium is in the evening and the faded Erythræum
prevails while Ascræus Mons is coming. In Japan Mk saw
the isolated Olympus Mons near the CM and Mo shot
it, and in Okinawa it gradually sank as
Propontis I made a figure. It may be possible to chase the rise and fall of the
nph as well as the dust complex at the southern
hemisphere.
On 13 July (195°Ls) also MVl made a good series of images from ω=040°W
to 095°W nearly every 10 degrees, and Mn at
Naha made observations eight times every 10 degrees from ω=082°W to 150°W,
and Hg videotaped from ω=108°W to ω=142°W. Mk also observed at ω=091°W, 101°W, 111°W, Km at ω=107°W, Id at
ω=130°W, 145°W, and WTn in Singapore observed at ω=115°W~127°W.
The pair of Ascræus and Olympus Montes were watched
amusingly from ω=100°W to ω=150°W. Arsia Mons was also visible in a
brownish tint and to the south of it there was a strange dark patch which must
have once appeared in 1973, maybe the east end of Valhalla so named in 1988. AKUTSU (Ak) made an
excellent images of the place on 10 July at ω=135°W. On the day (10 July),
Mo also made a good series of RGB and IR images
from ω=140°W to ω=160°W.
Steps of the Yellow Cloud
:
In the case of the southern summer dust cloud, the easterly plays
usually a main role to make the dust procession to the west. It however appears
that the expansion of the present yellow cloud, aroused in early spring, was
not caused by the easterly. Instead we consider that by an unknown reason or
reasons a faint existence of airborne dust gave rise to a strong local
disturbance and this may supply further airborne dust to bring about other
several resonances. Such sharp disturbances as seen on 28 June in Libya, on 1 July near Elysium, on 4 July at Dædalia, and those on 5 and 6 near Solis L as well as the
unknown source for the obscuration of S Meridiani
should all be resonances caused by the preceding expansion of a faint yellow
cloud. Such a rapid expansion to the northern hemisphere seen on 1 July cannot
be assumed without an earlier arrival of the thin dust caused by the stable
disturbance seen near M Cimmerium and Libya on 29 June. We have never
witnessed a rapid motion of any bright core to invade some remote areas this
time. The bright disturbance might be resonances, but they looked as if
independent each other. On 1 July we saw a violent disturbance near Elysium,
but before that we noticed that the lower sphere had already been covered well
by the yellow cloud. It was not so deep since the markings were all shot
through the IR light and also visually checked by the eyes. But it was very
apparent the surface was full of airborne dust. So if the depth of the cloud is
shallow and if one only refers to the monitor or to the IR images one may not
be aware of the existence of the precursory yellow cloud. Some presence of the
dark markings on the images does not deny the existence of a vast stirring of
the dust. The aspects on the images made by planetary experts for example by
PEACH (DPc) on
2 and 3 July at ω=334°W and by CIDADÃO (ACd) on 4/5
and 6 July cannot be said normal when the angular diameter kept
larger than 20 arcsecs. The yellow cloud went to be thick
in depth and around 5 and 6 July to the extent that only the summits of the
Montes appeared always as singular spots. The question whether the markings are
visible or not is a matter of degree, and the expansion of yellow cloud should
first be checked by the colour not by the fading of
the markings at an earlier stage. We don't consider that any of the present day
ccd images are made rich to realise
the deep colour of the yellow cloud.
Polar Regions :
We wanted to describe about the activity of the nph especially seen at the later part of the present period as
well as the apparently rapid recession of the spc, but
we postpone it and come back to the review later in a 2001 Note.
he next issue shall review
the observations during a fortnight period from 16 July (196°Ls) to 31 July
2001 (205°Ls). 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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