National Aeronautics and Space Administration

“ We have an image to show you the trail behind the Spirit rover. See the tracks. Lander out of view. See the back face of Adirondack. It may have looked really big but we drove right over it. Another interesting thing is that this was a drive to get to White Boat, a small white rock but also the first test on Mars of the rovers Autonomous Navigation System. That means the rover was in charge of its drive. The people on the ground tell it where we want it to go but it decides how to get there. That opens up new opportunities and distances. We can only plan so far in the images we see. ”

“ Reasonably fine layers could even have been some kind of lava flows. That was ruled out when we saw how thin these layers were. I think that the idea that this was some kind of course-grained sedimentary rock, a sandstone or something like that is ruled out by the high-res MI pictures. These look the way they're weathering like a very fine-grained ash or sediment. Spherical grains. One way to make round things is to tumble them. That's ruled out by the fact that they're round while still embedded in the matrix. ”

“ Third possibility is that they're what geologists call concretions. Concretions form when fluids carrying dissolved stuff diffuses through a rock and precipitates around a nucleus and it grows little spherical granules within the rock. ”

“ It is buff colored, or tan, finely laminated, thickness of layers a few mm at most. And then, embedded in it, like blueberries in a muffin, are these little spherical grains I'm calling spherules, spherical granules, because we don't know what they are yet, though I'm gonna run through the theories. They are different in color. The spherules are very, very gray - much, much different from the matrix they're embedded in. This next image is false color generated using infrared bands processed to really bring out those bright dots in the outcrop. ”

“ We also have a track of all the bounces. At the far left is where the back shell and parachute hit. This is a picture of the vehicle. One of the things to note is how bit it is relative to the crater. The lander fills a fairly sizable portion of the crater. If you'll go to the next picture, I _believe_ :D that we are actually seeing the rover. The rover will not be right because it has dark solar panels. Not at the right angle to see them glint. Won't know for sure until I take another picture after the rover has moved. ”

“ Lapilli, I'm still clinging to that one but compositional evidence not in favor. Another thing you might think about are something called ooids, grains that are rounded and created in a wave environment. ”