By the numbers Opportunity or Mars Exploration Rover-B


1/24/04: Date rover landed on Mars.

2: Number of rovers on that planet from Earth.

3: Number of weeks Opportunity landed after twin rover Spirit landed on other side of Mars.

100: Distance in meters the rovers can travel daily.

90: Days the rovers were expected to operate.

721 and counting: Days rovers have actually operated on Mars.

Source: NASA