Nine years ago today, the Opportunity rover landed on Mars and began one of the most astonishing chapters in spaceflight history. Expected to survive three months on the surface of the red planet, this plucky explorer has lasted 36 times that long. Along the way, it has inspired the world, changed our understanding of Mars, and led the way for the next generation of rovers.
Opportunity's most important finds include the existence of meteorites on the martian surface, the discovery of minerals such as hematite which form in the presence of water, and the first-ever observations of the martian atmosphere's temperature profile. These observations, in conjunction with data from her sister rover Spirit and the Phoenix lander, have greatly expanded our understanding of water and the water cycle on Mars. In carrying out these studies, Opportunity has logged a record 35 kilometers of driving on the martian surface.
Such a lifespan has taken quite a toll on the rover. It lost its sister in early 2010 when Spirit froze to death after getting stuck facing the wrong way. Problems with its wheels and robotic arm force it to navigate slowly and limit where it can look. Dust on its solar panels reduces the amount of power generated, which the rover needs both to keep warm and to continue its investigations. But, overall, Opportunity remains in remarkably good health.
So, as Opportunity begins an improbable tenth year on the surface of Mars, let's wish it good roving, better health, and best of luck!