19 April 2012
The Mars Exploration Rovers are amazing robots. Designed for 90 days[?], one of them has lasted eight years and is still driving around on Mars. To put its travels in perspective, here's a plot of Opportunity's total drive path on a map of San Francisco.
[Source: Ground track and extracted path.]
The path Opportunity has traveled over the past eight years would be an eight hour walk for a human. It also has yet to reach the distance traveled in just five months by the Soviet Lunokhod 2[?] rover back in 1973.
Successfully landing and operating any rover is a tremendous challenge. But I'd somewhat assume that we'd be able to progress more in the past 40 years. I'm looking forward to seeing what the Mars Science Laboratory can do this August -- assuming it survives its insane landing sequence.