Click for full image.

Today’s cool image is cool not because of anything visible within it, but because of its location. The picture to the right, cropped to post here, was taken on May 27, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). While the terrain shown is a relatively featureless plain of craters and gullies not unlike the surface of the Moon, what we are really looking at is the peak of Mars’ tallest mountain, Olympus Mons.

That’s right, this spot on Mars sits about 70,000 feet above Mars’ mean “sea level”, the elevation scientists have chosen as the average elevation on Mars from its center. At 70,000 feet, this peak is more than twice as high as Mount Everest on Earth.

Yet you wouldn’t really know you are at this height if you stood there. The scale of this mountain is so large that this peak, which actually forms the southern rim of the volcano’s 50 to 60 mile wide caldera, is actually relatively flat. If you stood here, you would not see the vast distant terrain far below. Instead, you’d see an ordinary horizon line in the near distance only slightly lower than where you stand.

The overview map to the right marks this peak by the black dot. The terrain here is so flat because the caldera’s rim is itself so wide, extending from 10 to 30 miles from the caldera to the point where the mountain begins to slope downward to the vast lava flood plains that cover hundreds and hundreds of miles of Mars in all directions.

In fact, the scale of this mountain would make the skill to climb it more in line with a hard core hiker than a mountain climber. At few points from bottom to top would you ever have to scale a cliff. Instead, the journey would be one long, long, long trudge up a never-ending slope, running almost 300 miles from base to peak. Even the mountain’s edge, that seems so much like a cliff, is actually less a cliff and more a somewhat steeper slope. All you’d need at a few points is to switch back a few times to lessen the grade.