Signs of water jumped out almost immediately, and just six weeks after Opportunity landed, NASA held a press conference in Washington to announce definitive proof that water once existed on Mars.

• 水的遗迹几乎立刻跃入眼帘，“机遇号”着陆仅仅6周后，nasa就在华盛顿举办记者招待会，向外界公布了火星曾经有水的确凿证据。