The atmosphere of Mars is not thin

[aurora]

The atmosphere of Mars is more extensive than the Earth atmosphere:

1- The sun-set afterglow is more extensive and lasts more that on Earth.
2- The dust whirling storms extend high in the atmosphere to about 12miles or 20 kilometers, which is more than that on Earth.
Such height of the dust storms on earth extends to about the height of the troposphere where the winds and storms exist.

The implication of the sun-set afterglow:
This afterglow is a manifestation in the troposphere and is ascribed to the dust particles in this troposphere which on Earth extends to 11-14 kilometers, and in the polar regions it is much less in height.

The implication of an extensive atmosphere on Mars more than that on Earth:
It indicates Mars is larger than Earth, not smaller.

[ The Wrong Calculations of Astronomers Concerning Mars ]

[freedom]

Here is an image from NASA and its caption:

http://www.nasa.gov/mission_pages/MR.../pia15545.html

[freedom]

And this is about the sunset afterglow on Mars: which is estimated as long as 2 hours more thanthat of Earth which lasts for about 1.5 hour.

http://www.nasa.gov/multimedia/image...ature_347.html