"We're excited because from here on out what we're going to do is a repeat of something we've done before," Dr. Grotzinger says. "With that comes more confidence, a chance for fewer surprises, and increased efficiency."
Yet even the tests were a bit like movie trailers, giving researchers hints of discoveries to come – yielding evidence for an ancient stream bed and rock types paving parts of the crater floor that appear to have formed in the presence of water.
Geological models of the surface, based on data from Mars orbiters, pointed to Gale Crater's floor as a once-watery site.
"But we had no idea that we were going to find the rest of this stuff," he says, referring to the types of rocks and their flagstone-path-type layout at Curiosity's current location – a zone on the crater floor the team has dubbed Yellowknife.
If Curiosity had "gone long" and landed on the flank of Mt. Sharp instead of its planned landing site, "and we would have found stuff like this, we could have considered it to be very much the stuff we chose the landing site to go find," Grotzinger says.
Mt. Sharp is a towering summit inside Gale Crater. Its strikingly layered slopes hold the promise of revealing much about the early history of Mars's climate and the geological forces that built the mountain. Near the base, Curiosity will be hunting for signs that the crater might have been a suitable place for life to emerge shortly after Mars formed and its climate – it is believed – was warmer and much wetter.