Hovering over the image, as I did when I took the screen grab above, reveals the reason: today is the birthday of Giovanni Schiaparelli, whose canal-covered maps of Mars fired the imaginations of countless planet-watchers. While Mars didn't turn out to have any canals, Schiaperelli and his maps are still fondly remembered among Mars enthusiasts.
This all ties in to something that a post on Phil Plait's Bad Astronomy reminded me of yesterday: Google Mars. Google Mars is actually bundled with the 5.0 release of Google Earth - so if you have the latest version of Google Earth, you also have access to global maps of Mars! Here's a quick introduction:
I downloaded the latest version of Google Earth a week or so ago, so I just dove right into the Mars option without really paying much attention to the tutorial. The first thing you see (after a brief initialization) when you open the Mars option is this:
Mars! The patchwork strips of different resolutions have to do with how different regions of Mars have been imaged by different orbiters. I zoomed in for a closer look:
I was intrigued by the images on sticks that were dotted across the surface. I knew there were symbols used to indicate landing points and specific areas of interest, but these looked like...animals?
Closer inspection showed that these images indicated where I could find Amazonian Manatees, Aye-Aye Lemurs, Rodrigues Fruit Bats, and other endangered species on the surface of Mars! Apparently the Last Chance to See tour markers that I had downloaded from Gareth's Another Chance to See had been superimposed on the surface of Mars!
(I briefly toured Google Sky, and saw the same effect there when I discovered that a small green marker near, I think, Sirius was actually an image of a Komodo Dragon!)
I tootled around a bit, tossing around the Red Planet like it was a bowling ball in a ball polisher. Almost at random I picked out a region of higher resolution and began to zoom in on it.
A quick zoom on this terrain revealed strips of another color tucked away - even higher resolution images. I zoomed in further.
This looked like the edge of a canyon - and the blue stripe down the middle suggested that there was an area of even higher resolution there! I kept zooming in.
This is really interesting looking terrain. On Mars. On another planet. And here I was, zooming into it. What was that bright thing near the top?
A closer zoom revealed more interesting stuff: fractured terrain, a canyon wall, and - was that a piece of the canyon that had detached itself?
Zooming in even closer suggested that, yes, this white trapezoid (about 275 feet, or 84 meters, across its "base") appeared to be a chunk of the white terrain in the lower left that had broken off and crashed below, leaving scattered boulders and...
...plumes of billowing dust?
No. No way. Clicking on a red informational box on the border of the image, I got this information:
Rocky Mesas of Nilosyrtis Mensae RegionWell, of course any proposed landing site for the Mars Science Laboratory would have been gone over with a fine-toothed comb. The likelihood that someone would have overlooked an image of an avalanche in progress in that neighborhood is virtually nil.
This image was taken by the High Resolution Imaging Science Experiment (HiRISE) camera on board NASA's Mars Reconnaissance Orbiter (MRO) spacecraft.
See this image’s observation information page.
Observation ID: PSP_003231_2095
Image of: Proposed MSL landing site in Nilosyrtis
Location: 29.29°N 73.29°E
Acquired on: April 5, 2007
Here's a fun little detail: a boulder apparently fell, rolled, bounced, rolled, and bounced again, skipping over the surface several times before it came to rest. That boulder is just eleven feet across - 3.5 meters. The smallest details visible in this image are less than two feet across, the size of a small dog! On Mars!
Here's an oblique view of this region. I have not exaggerated the vertical scale, but it is possible to magnify this so things appear stretched to three times their actual height.
If you'd like to check this out, you can open Google Earth, select the Mars option, and zoom to Latitude 29°23′11.33″N, Longitude 73°17′3.60″E (or just "Fly To" PSP_003231_2095). Let me know what you think, and what else you may discover on Mars!