From Nicolas BIVER
@. . . . . . . . .Mars Storm under stormy
weather! Storm under storm...that's a bit the way I can describe my only
observation of the event, recently.
I don't know if you got some information from European observers, but our
longitude should have favored the observation of the obscuration of Syrtis
Major by the dust for the last 2 weeks.
Unfortunately I left
Since then, I got a telescope (25cm on the week-ends and 20cm in the
week) to use after July 7, but weather did not cooperate much, either in France
or in Noordwijk, Netherlands, where I finally got in
touch with Mars on July
12.9 UT:
From there Mars culminates barely at 10 degrees above horizon (52.2 deg.
N), and I actually observed it at 8 degrees (Second drawing)...For those who
can get it 40 degrees high in the sky, I observe it through 4 times thicker atmosphere
and turbulence!
Fortunately this Netherland countryside is flat
like sea and seeing not so bad as wind is more likely laminary:
On July 12.9 the seeing was good for what you would expect so low, fair to poor
in absolute.
The problem was that sky cleared up (it took a bit longer to clear Mars
low at the southern horizon) thanks to the wind of a storm system, blowing more
than 60 km/h, and I had also the problem of not getting my scope blown away! [even behind (low) buildings I couldn't find some rest from
these though windy conditions]
In any case, at CML 253, Syrtis Major should have been clearly visible
(by comparison to a drawing of June 5 – see http://www.lesia.obspm.fr/perso/nicolas-biver/marsnews.html#M2001)
but was not identified although the NPC and Utopia seemed clearly identified
(so not too much a seeing/wind shake effect). The SPC was tentatively seen
small, also, most of disk being patches of low contrast albedo
features, one likely related to Mare Cimmerium?
I wish you all better observing conditions for this on-going storm [on
Mars, please not on Earth!!],
(
@. . . . . . . Thanks for the update on Mars
dust storm.
From France, mostly (July14.9; 20.8; 21.8 and .9), plus July
16.9 from Noordwijk, I made a few drawings of Mars (I
hope to find a way to scan then soon), with CML 140 to 218. The border of the
NPC/NPH is the darkest feature, but the NPH may have been partially obscured by
dust at some times (?).
M. Cimmerium seemed lightly and partially visible and M. Sirenum quite
ill defined. There is actually a darker complex, roughly between Longitudes 80
and 120 and in the southern hemisphere (covering Solis Lacus - Aonius Sinus - Phoenicis Lacus - Tithonius Lacus (up to Tharsis?) region) that seemed a bit
more obvious last Week-end (July 20.9-22.8), with lighter (storm clouds)
patches to the South and at lower CML, apparently.
I have otherwise a more general question:
Although it has now been clear to all of us that we are
watching a major global dust storm on Mars, why hasn't it be reported in an IAU
Circular?
I don't know if it is usually done, but so far one was issued about the
sighting of
It may be now a bit late, but wouldn't it have been an opportunity to
publicize amateurs (continuous) contribution in Mars observation to the
astronomical community (even if it has also been monitored by some (MGS)
professional means)?
What do you think?
(
@ . . . . . . . Dear Masatsugu, CMO
observers, I attach here some drawings I made of Mars while no so many feature
were visible due to the dust storm...
I
will send more soon and prints by mail, as well as post them on my web page (in
(
@ . . . . . . . Dear all Mars observers, Here
are 2 drawings made at CMLs (31-50) where much more
should be visible, although Mars was only 11 degrees high in the sky from the
How long can we expect such a storm to
last? When was the previous major
one of comparable extension and duration? [in the 70s?
or some more recent than Viking 1&2
time]
(2 August
@. . . . . . . Please find here copies
(actually color prints of ~100 dpi scans of the originals, that are available
on my web page) of my recent Mars drawings since my
last mail. Part of them now cover the large dust storm period that started a
month ago, and although it is now hard to distinguish clearly any features
(contrast are exaggerated on the drawings) it makes Mars even more fascinating,
like a new planetary surface to discover!
On the other hand, I partly moved to
Now Mars is moving away from us, getting smaller and closer in the sky to
the Sun. But viewing conditions shouldn't worsen any more during the next 5
months: I have noticed that it will transit always after sunset (which is
happening earlier every day), during twilight though, until December! In
addition, after September it will also get higher in the sky.
For now, I try to observe Mars as often as possible, watching the
evolution of this major storm.
Clear and Steady Skies,
Regards,
(
Nicolas
BIVER (Noordwijk, the
Netherlands/Versailles,
