Mars Section        


Highlights of the 2015-2017 Mars Apparition


Mountains of Mitchel Captured from Ls 253 to Ls 255.


Images of the Hellas-to-Argyre Dust clouds in September are below. In my opinion, these clouds are produced by winds from the continuing sublimation of the CO2 ice cap.




The images below from April 5th to May 9th provide evidence for strong South to North straight-line winds in the Hellas basin from Ls 130 to Ls 150. This period is the middle of winter in the Southern Hemisphere. I propose that the sublimation of CO2 ice produces straight-line winds. With the ice exposed to sunlight, the frozen CO2 sublimes, creating enormous winds up to 400 km/h.[2] Each southern winter, the seasonal CO2 ice cap covers the surface to a latitude of 50°.[28]  This means that the Northern edge of the cap bisects Hellas.  See Christopher Go’s and Anthony Wesley’s March images below the April and May images. The grey-colored CO2 cap covers the Southern one-fourth of Hellas. It can be deduced that sublimation winds here contribute to the waves of dust in Hellas. Hellas is immense with the South to North diameter about 1,300 miles that is roughly the distance from the US-Canada border to the Pan-handle of Texas. So with that diameter, a significant temperature gradient is likely in the South to North direction that can continue the strong sublimation winds that carry immense waves of dust from South polar regions to the Northern wall of Hellas.  These detailed images by Clyde Foster and Efrain Riveras Morales show what I think are the results of these winds. References are courtesy of Wikipedia.

Also note that the floor of Hellas is blue in the April images and white in the May 9th image. A blue color can mean the presence of H2O water vapor but what would be its source? Temperatures in the South polar regions are warm enough for CO2 sublimation but not H2O sublimation. However, the north polar cap of Mars does get warm enough for H2O sublimation. Maybe this is a source of the water vapor. See page 399 of a Traveler’s Guide to Mars by William K. Hartmann published 2003.


First recorded images in this apparition of Wind-Blown Dust Clouds in Hellas. Also, the Northern extremes of the SPC are visible and are grey colored. I don’t remember ever seeing the CO2 part of the SPC in amateur images! Pardon me for saying “Wow”. See images below. About one-fourth of Southern Hellas is covered by the seasonal cap.

Many small features distinguishable on Clyde Foster’s image below!


Images from Feb 17, 2016 to Mar 01, 2016. Have you ever seen

such a broad expanse of white clouds over the Martian disk?


 Images from February 7th, 8th and 12th 2016

These images show heavy concentrations of H2O clouds in the equatorial regions of Mars. The gaseous clouds sublime from the granular North Polar Cap and move Southward higher and higher in the atmosphere. To the right(West) of the CM orographic clouds are visible over 3 of the Tharsis volcanoes. To the East of the CM, Acidalia planita and Chryse planita are like deep valleys in the Northern hemisphere where possibly an orographic type of action produces equatorial H2O clouds. But, it may be some other mechanism. Also interesting, the green and blue images show bright areas indicating low altitude fogs and clouds above that. Further, the February 7th and 8th red images show the same bright areas that suggest ground frost.

Images from December 11th 2015


The dark markings are sharp and very detailed with Mars only 5″ in diameter on 12-11-2015. A stand out marking is Nilosyrtis that had mostly vanished in the last 5 apparitions. A noticeable change is a new prominent dark band under Sabaeus Sinus.  It is late Spring in the Northern Hemisphere. During Spring the North Polar Cap shrinks unevenly leaving ice outcrops such as the one shown here in Uchronia.

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