Monday, 30 June 2008

NASA's Misrepresentation of Mars

Mars' northern orange sky and horizon, seen by NASA's Phoenix Mars Lander. The lander's solar panel and Robotic Arm with a sample in the scoop are also visible. The image was taken by the lander's Surface Stereo Imager looking west during Phoenix's Sol 16 (June 10, 2008), or the 16th Martian day after landing. The image was taken just before the sample was delivered to the Optical Microscope. (NASA/JPL-Caltech/University of Arizona/Texas A&M University) visit the link for the full gallery including pictures taken by orbiting NASA and ESA probes)

AWESOME PICTURES ... but the colour representations here are very misleading.

The colour in many shots has been altered to portray Mars as the "Red Planet" rather than revealing the darker colour of the soil and light blue sky.

First thing's first: THE MARS SKY IS BLUE. The colour of the sky works the same way as it does on earth. The relatively short wavelength of blue light is bent by the small molecules that make up the atmosphere.

The only time the sky becomes RED is when there is a heap of Dust blown up. Being bigger than CO2 or O2 molecules, the Dust reflects the longer wavelength of Red light. Same as on Earth.

And we also know the Mars atmosphere is devoid of dust a great deal of the time from the space based photography provided by the orbiters. The shots we are getting of the surface are crystal clear - no dust haze !

On most days the Mars sky is a pale blue colour thanks to the thin atmosphere's minimal light scattering effect. Same as at high altitude on earth. Same physics, different planet.

NASA also likes to show the Martian SURFACE as much lighter than it actually is. Just as the sky has been altered, the ground colouring has been presented in a way to represent a "Red Mars."

Ordinarily the soil is mostly a DARK reddish colour. The effect of this soil on light operates the same as our Moon. The Moon's soil is a very dark grey and yet reflects the sunlight as white -somewhat like a mirror. The Mars soil on the other hand is dark and reddish, and reflects the sunlight as light Red.

Altering images is fine in terms of revealing certain details but it can hinder comparative analysis based on colour comparisons against earth geology and atmospheric physics.

I don't know why, but NASA likes to obfuscate various facts about Mars.

Google all this stuff and find out for yourself (try typing "why is the sky blue" and go on from there).

[Posted at the SpookyWeather blog, June 30th, 2008.]

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