Ashwin Vasavada, project scientist for the Mars Science Laboratory mission:
It’s a summer of milestones for Mars Exploration. Fifty years ago, Mariner 4 became the first spacecraft to take close-up pictures of Mars. Thirty-nine years ago, the Viking 1 Lander became the first spacecraft to successfully land on the Red Planet. And now, Curiosity celebrates 3 years on Mars — operating well over a thousand Martian days.
In three years, the 1-ton rover has made some significant findings, including encouraging information about radiation levels on the Martian surface, the presence of methane, and — of course — water on the Red planet.