What you see is not always what you get.

At the end of sol 12, after completing observations of Kaibab, the FIDO team was disappointed because they couldn't reach the piece of bedrock they wanted to further study with the robotic arm instruments. The team decided that the overhang on the Kaibab rock made it too dangerous to proceed in trying to extend the arm.

The team was faced with a dilemma: should they send the rover north or south on the next sol? Toward the north sat a light colored, flat area named "Bonneville" that scientists thought contained recently formed mud cracks. Mud cracks might indicate that water, and possibly even life, existed at the site recently. However, there was also the option to go south, where some contrasting darker and brighter rock units presented by orbital data had caught scientists' attention. These unique rock units were not evident at the rover's present or past locations, and some scientists felt that investigating a broad range of rock types was more important than the investigation of mud cracks, which were believed to be a fairly common feature in the region.

After a long period of vigorous debate, scientists decided to head toward the Bonneville site, hoping to find the mud cracks. Upon arrival, to the scientists' surprise, there were no mud cracks! Instead, the scientists found bedrock, which is the type of rock they had wanted to test at Kaibab. The bedrock at Bonneville was less dangerous to reach. The bedrock had been scoured by past water flows, which had eroded the rock surface over time, making it very accessible to the FIDO rover instruments. Scientists collected data using the APXS, Microscopic Imager (MI), and Mössbauer instruments.

Jim Rice

"Exploration is a trial and error process," explains Jim Rice, an astrogeologist from Arizona State University, who also helps decide where to point the camera on the Mars Odyssey orbiter. "Scientists formulate hypotheses by analyzing observations and data. Sometimes the hypothesis is proven wrong, but this is not a bad thing, because it eliminates one possibility and helps bring scientists closer to a better understanding of the true nature of the landscape."

Science team members all seem to agree: you can't always predict what you'll find once you venture out to a new place, but you can always find something interesting to study once you get there. After all, humans have only landed spacecraft on the surface of Mars three times before (Viking 1 & 2 and Mars Pathfinder), so there's much still to discover.