Universe Today posts a fantasy what-if picture under title, "What Mount Sharp Would Look Like on Earth." Mt. Sharp, a three-mile high mount in Gale crater on Mars, appears under blue skies. The article reassures reader to avoid confusion below:
"Mars hasn’t sprouted a nitrogen-and-oxygen atmosphere overnight. The image above is a crop from a panoramic mosaic made of images from NASA’s Curiosity rover, showing Gale crater’s central peak Mount Sharp (or Aeolis Mons, if you prefer the official moniker.) Don’t let the blue sky fool you though — the lighting has been adjusted to look like a sunlit scene on Earth, if only to let geologists more easily refer to their own experience when studying the Martian landscape."
The present writer wonders? A prior post also shows blue Martian skies, "Martian Sky Is Blue."