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The International MarsWatch Electronic Newsletter

Volume 3; Issue 2
December 2, 1997
Circulation: 1490

Mars Symbol Mars Symbol

Dear Marswatch participant,

I have just received the following report of extensive local and perhaps global dust activity on Mars from members of the Mars Global Surveyor science team. Along with the MGS data, Todd Clancy reports corroborating evidence for rapid high altitude warming of the atmosphere (consistent with increased dust loading) from recent microwave telescopic observations.

As always, additional optical and infrared observations of this dust activity would be very useful for tracking the growth and decay of Mars dust activity, and for assistance with calibration of the MGS science instruments. Mars is a very challenging observational target right now (close to the Sun, angular size 4.6 arcsec), but many of you have risen to the challenge before... Go catch some dust!

If you are able to obtain images, please upload them to the pub/incoming directory at the anonymous ftp site, as the JPL Pathfinder ftp site is no longer supported.

--Jim Bell
Cornell University

Mars Symbol Mars Symbol

Summary of Mars Dust Activity Observed by the Mars Global Surveyor Spacecraft

Forwarded Message from John Pearl and Mike Smith

Status of the Noachis+ Dust Storm -- 12/01/97

Continuing analysis of TES data of the dust storm in Noachis and points west (and east). Results below are based on the entire dataset from drag and all rolls for each orbit.

P049 (Ls=224°; 11/25/97):
Small-scale (~300 km) dust activity observed in the Noachis region.

P050 (Ls=225°; 11/26/97):
Excellent coverage, with drag pass and first roll giving data centered on the Noachis region. The storm covers latitudes 15°S-50°S, between longitudes 325°W-360°W/0°W-5°W.

P051 (Ls=226°; 11/29/97):
Scattered coverage of the storm region. It remains within previous latitudes, but spreads to 15°W, with indications of activity near latitude 25°S penetrating eastward to 305°W. Limited activity north of Argyre (~40°S,~50°W); some increase of dust up the eastern slope of Sinai and Solis Plana (~25°S,~65°W).

P052 (Ls=227°; 11/29/97):
Good coverage east of 345°W; sparse coverage to west. Activity continues to spread westward. Fairly intense activity to 55°W at 40°S, with limited increases as far as 70°W. Storm becoming fairly intense into Hellespontus Montes, and as far east as 310°W at 55°S. Southern extent to 60°S near zero longitude.

P053 - drag and first roll only (Ls=227°; 11/30/97):
Consistent with reports by MOC, the storm continues to intensify, spreading south onto the polar cap along a broad front from 30°W eastward to 290W. Considerable activity north of Argyre, and from 10°S to 30°S at longitude 290°W (we have only drag pass data here so far, and so cannot define the E-W extent of this activity). Significant increase of low level dust from there north to 35°N.

Mars Symbol Mars Symbol

Jim Bell will continue to maintain the email distribution list as well as the various Cornell and JPL Marswatch-related WWW archives. If you are receiving duplicate copies of the International MarsWatch Electronic Newsletter, or you want your name added to or removed from the distribution list, please send him an email at

Jim Bell
Cornell University
Department of Astronomy
Center for Radiophysics and Space Research
424 Space Sciences Building
Ithaca, NY 14853-6801
Phone: 607-255-5911; fax: 607-255-9002

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