DUST ACTIVITY ON MARS

[Whitters]

DUST ACTIVITY ON MARS: Mars has been receding from Earth and fading since
last August. This week, though, the red planet has gotten a smidgen
brighter. The reason: a dust storm is brewing. Bright dust clouds on Mars,
reflecting sunlight more than the underlying terrain have boosted the
planet's total brightness by about 0.17 magnitudes.

Amateur astronomers using 12 to 16 inch telescopes have been tracking the
dust clouds responsible for this change.  You can see their pictures on
spaceweather.com. So far the dust storm is a regional one; it spans only a
fraction of a martian hemisphere.  Sometimes such clouds grow to encircle
all of Mars, but that hasn't happened in this case--at least not yet.

[Mike]

This dust may well effect the craft due to land next week. Dust on solar panels is not good !!

[Rick]

(From BAA Electronic Circular 00127)

Martian dust storm: Chryse-Argyre-Thaumasia

A regional dust storm has broken out on Mars. Dr Donald Parker (USA) writes of his CCD images taken on December 13 (Ls = 315 degrees): "A significant dust storm has arisen to cover Chryse, Erythraeum M., Aurorae Sinus, Candor, with smaller clouds in northern Argyre and possibly Aram." On December 9-10 Chryse and Candor were bright, especially in Parker's red light images, but no definite obscurations were present. Typically storms in this region break out in eastern Valles Marineris or in southwest Chryse (classical SW Xanthe). Data from December 14-16 indicate a spreading of the dust to include part of Thaumasia.

Bad weather has plagued observational work in the UK throughout December to date, but it can stated that CCD images by Michael Foulkes on December 5 show the region to have been normal then, whilst images by Damian Peach on December 9 and drawings by the Director on December 15 show the longitude of Hellas to be normal too. Visual work by Gianluigi Adamoli (Italy) on December 3 provides further confirmation, as do drawings by Gerard Teichert (France) on December 7-9. (This shows the value of routine work, which far too many observers have already abandoned!)

The seasonally latest planet-encircling dust storm known began at Ls = 311 in 1924 December, suggesting that the present event will not exceed large regional status. The December 13 images recall a similar regional event in 1990 November.

Mars is well-placed for northern temperate observers, although good seeing will be needed to identify features upon the small disk. From western Europe, only the eastern end of the dust-affected region can be presently seen at the morning terminator with the planet well past the meridian, but the storm longitudes will be better placed for viewing later as they become visible over the evening limb.

Richard McKim,
Director, BAA Mars Section, 2003 December 16.

[ This Message was edited by: Rick on 2003-12-18 11:32 ]