Saturday, March 9, 2013

What Color is the Martian Sky?


Madame L,
 
Great blog! Thanks to Jeff for introducing me to it.  

I do have a question, and who better than you to answer it?
If you were standing on the surface of Mars and staring into the sky, would the sky be blue?  (And why?)

Sincerely,

Not a Martian


Dear Fellow Earthling,

Thank you for reading Madame L's blog, and thanks for your question. 

Madame L has been asking these kinds of questions ever since was a little girl asking her daddy why the sky was blue. He gave a long explanation which was unconvincing to Madame L's four-year-old self, even though it was probably the right answer.*

Mars Pathfinder panorama of landing site taken by IMP





Check out this photo taken by NASA's Mars Pathfinder. Is that eerily beautiful, or what? The sky is a kind of yellow tinged with brown, and here's the answer to your second question:

This color is caused by a small amount of magnetite in the dust particles in the atmosphere.

Madame L was fascinated to read, though, as she researched this topic, that getting an image to show the "true" color of the sky of Mars is really difficult. Maybe when we actually have people there, we'll have a better idea of the color.


Keep those questions coming! (But please don't ask about Rayleigh scattering, which makes little to no sense at all to Madame L.)

Sincerely,

Madame L


1 comment:

Jeff Wynn said...

I recall once seeing a NASA rover image that had been color calibrated against a color wheel... and the non-dusty sky of Mars was pinkish red.

But then again, the Romans reported in 6 - 8 separate, unequivocal documents that the star Sirius was red-orange. It's the brightest star in the sky right now (mainly because it's just 8 light-years away), and is a hot and certifiable blue-white spectral type A1V today.

It's been puzzling Latin-reading astronomers for at least two centuries.
~~~~~