Forthcoming 2005 Mars
(4)
Masatsugu MINAMI
|
T |
he apparition of the 2005 Mars is just the
next apparition of the great apparition, and so as far as we experienced it
must be akin to the 1990 apparition or to the 1973 apparition. In order to draw
up a plan of the campaign in 2005, to look back on these preceding apparitions
may be instructive.
Similar apparitions occurred several times during these one hundred years
as are they listed as follows (in the order of the opposition days)
27 Nov 1990 δ=18.1"
25 Nov 1911 δ=18.3"
18 Nov 1858 δ=19.2"
07 Nov 2005
δ=20.1"
04 Nov 1926 δ=20.4"
25 Oct 1973 δ=21.5"
20 Oct 1894
δ=21.7"
10 Oct 1941 δ=22.8"
where δ implies the maximal angular
diameter when the planet was closest to the Earth.
As seen, the 2005 Mars is quite akin to the
1926 apparition (79 years cycle), and further we should say the 2005 Mars lies
mid-way between the 1990 and the 1973 apparition. The 1973 Mars should be said
similar to the 1894 Mars. The 1941 Mars was particular, and it was quite akin
to the grand opposition (opposition making a twin with the 1939 great
opposition whose δ was 24.1" ) and has been remembered as the year
when Bernard LYOT was active at the Pic du Midi and produced a lot of excellent
composite images.
Here
we touch a bit upon the year of the 1894 Mars: Since it was the first year
Percival LOWELL planned a Mars campaign at
As to the 1894 Lowell Mars, the present writer gave a series of talks at Anamidzu
Lowell Conference in May 2004 based on LOWELLs Mars published in 1895, and also
reported about it, and so the following items are no more than a repetition,
but here we pick out the least cases that are appropriate to our plan of the
2005 observation. We never here enter into the logics or perspectives of P
LOWELL.
We should first say the observation at
The observation was carried from 22 May 1894 to 3 April 1895. During this
long period they made a total of 917 drawings. On 22 May 1894, the angular
diameter was only about 8 arcsecs, and even then they started the routine
observation. We suppose this must have depended on a strong suggestion by W H
PICHERING to start their observation from the southern early spring within the
period the south polar cap was not so melted away. Note that it was on 28 May
that they got into Flagstaff, and really on 31 May LOWELL observed Mars for the
first time with PICKERING but with a 30cm refractor, while it was on 1 June
that they started to observe by the use of a main 45cm F/17.5 Brashear refractor (the famous Clark 61cm refractor was
installed in July 1896, and could not be used in 1894). So we should say Mars
arrived before their plan. On 22 May, 24 May, 25May and 27 May they had to use
a 15 cm refractor, the one LOWELL once brought into Tokyo, but on 22 May W H
PICKERING already found a rift inside the spc and so they were forced to count
22 May into as the first day of their observation period.
As far as our experience was concerned, we checked in 1986 that the centre
of the spc began to be shadowy compared with the surrounding brighter torus
ring just before the southern spring equinox λ=180°Ls, and as noted again in Report 11 of CMO #276,
Parva Depressio was observed in 1988 from 3 June 1988 (λ=208°Ls) at ω=161°W, and in 2003 Parva Depressio was quite
evident on Maurice VALIMBERTIs image on 24 June 2003 (λ=209°Ls) at ω=127°W, and so we can
suppose PICKERING was successful in detecting Parva Depressio on 22 May. On 31
May, they observed the surfaces showing Syrtis Mj and the rift was considered
extending from 170°W to 345°W, and hence this was mainly occupied by Rima Australis including Parva
Depressio. On 10 June DOUGLASS found another rift. The shadowy areas inside the
spc play a serious and decisive role on
In 2005, the days correspond to the beginning of May 2005. On 10 May 2005, and λ=208°Ls with the angular diameter
δ=7.1". If we want to pin down the spring equinox, we must start from
around 24 March 2005. With respect
to the happening of the 2001 dust storm, it is necessary to for us to be on a
train of observations in March. Fortunately the sub-Earth point latitude on 1
March is 10°S, and henceforward the south pole declines further to us, and reaches
about 25°S around the beginning of June. Next bottom will visit at the end of
September to 10°S, but then rises up again.
We here digress, but we should like to stress that from the point of view
of the dust circumstances which we encountered in 1973 (a sister apparition of
1894), it is also preferable to start earlier: It is known in 1973, at least
two conspicuous dust disturbances occurred (biggest one was onset at λ=300°Ls), but there is a reason that there must
have occurred another big dust disturbance much earlier which influenced the
following dust storms. In 1973, Professor S MIYAMOTO started on 28 April 1973
(λ=195°Ls, δ＝7.1"), and we can consider that this was
determined from the same background as employed by the Lowell team, but even
then this was too late from the view-point of the dust phenomena.
Among many observations made by the Lowell team, LOWELLs detection of two bright spots in the midst
of the spc on 7 June is known as a pioneering work of the flare detection on
the planet Mars. They dazzled like stars and flashed out and then disappeared
after a few minutes. He calculated their position located at Ω=280°W~290°W, Φ=76°S and so it could be regarded to be
associated with Novus Mons when it stayed still inside the spc.
As was pointed out also at the Conference last year, we may say DOUGLASS
had a keen eye to the darker part, while
During the campaign, it was reported they detected a total of 736
irregularities along the terminator, 694 out of which were measured. Of these
403 were depressions and 291 were the projections. We dont here discuss about the unbalance of the
numbers of the depressions and projections, nor their causes as atmospheric or
geographical, but the concern about the terminator of the
DOUGLASS made also an interesting observation on 26 and 27 November GMT of
a bright spot which was detected in the unilluminated part of Mars. The one
observed on 26 November at 4:35GMT was on the southern part of Protei Regio,
and the one on 27 November appeared at 5:15 GMT nearly 9 degrees north. The
description is quite detailed: if similar observation is made they are easily
compared. They considered this to be an atmospheric variation. (Here the date
and time have been converted into the modern GMT. If the time in the
Percival LOWELL was not a serious observer
and often he was absent from Flagstaff even when the planet is in the very
season, but we should say his plan of the 1894 campaign was quite successful
maybe under the advisory PICKERING to cover the whole season of the southern
hemisphere. As the spc thawed, Novus Mons was detached and they observed around
from λ=238°Ls the deviation of the centre of the spc from the pole to the direction
of ω=054°W, and decided the spc disappeared on 13 October. This was slightly before
λ=300°Ls and should be said earlier than expected (at those time, it was
believed the cap does not vanish as nowadays and soon grow large).
The
1894 Mars was thus seen rather high in the sky from Flagstaff and we want to
emphasise the 1894 Mars provided LOWELL to survey the possible cycle of the
southern hemisphere to match his desire to be acquainted with the Martian
season during the period from the season where the spc was largest to the
season where the spc melted away. We also suggested their observations of the
terminator should be revived in some sense.
