Well not for this old rock-hound, who remains duly impressed a full two weeks after the announcement was publicized. This truly is the smoking gun for the former presence of running water on Mars. Previous studies have shown that minute amounts of water still reside near the Martian poles and perhaps beneath the Martian surface elsewhere. But this is verifiable and visible evidence that rivers once ran on Mars! (A River Ran On It).
In this posting, I include images released by NASA with their own captions beautifully describing each one (I modified the captions slightly to reduce redundancy). The full story as posted on the NASA web site can be read and accessed here. Wow! This is really impressive. Stay tuned to NASA and this blog for more fantastic discoveries from Mars.
Where Water Flowed DownslopeThis image shows the topography, with shading added, around the area where the rover Curiosity landed on Aug. 5 PDT (Aug. 6 EDT). Higher elevations are colored in red, with cooler colors indicating transitions downslope to lower elevations. The black oval indicates the targeted landing area for the rover known as the "landing ellipse," and the cross shows where the rover actually landed.
An alluvial fan, or fan-shaped deposit where debris spreads out downslope, has been highlighted in lighter colors for better viewing. On Earth, alluvial fans often are formed by water flowing downslope. New observations from Curiosity of rounded pebbles embedded with rocky outcrops provide concrete evidence that water did flow in this region on Mars, creating the alluvial fan. Water carrying the pebbly material is thought to have streamed downslope extending the alluvial fan, at least occasionally, to where the rover now sits studying its ancient history.
Remnants of Ancient Streambed on MarsNASA's Curiosity rover found evidence for an ancient, flowing stream on Mars at a few sites, including the rock outcrop pictured here, which the science team has named "Hottah" after Hottah Lake in Canada’s Northwest Territories. It may look like a broken sidewalk, but this geological feature on Mars is actually exposed bedrock made up of smaller fragments cemented together, or what geologists call a sedimentary conglomerate. Scientists theorize that the bedrock was disrupted in the past, giving it the titled angle, most likely via impacts from meteorites.
The key evidence for the ancient stream comes from the size and rounded shape of the gravel in and around the bedrock. Hottah has pieces of gravel embedded in it, called clasts, up to a couple inches (few centimeters) in size and located within a matrix of sand-sized material. Some of the clasts are round in shape, leading the science team to conclude they were transported by a vigorous flow of water. The grains are too large to have been moved by wind. This image mosaic was taken by Curiosity's 100-millimeter Mastcam telephoto lens on its 39th Martian day, or sol, of the mission (Sept. 14, 2012 PDT/Sept. 15 GMT).