For about the past 30 months, the Opportunity rover has been exploring Cape Tribulation on Mars, a towering ridge on the rim of Endeavour crater. Now, Opportunity has finally left that location, to continue its journey southward down the western side of the crater rim. The views have been scenic from the top of Cape Tribulation, but now it is time to move on, and head to the next major target, an ancient gully not too far to the south-east, also on the crater rim. This gully is thought to have been carved by running water millions or billions of years ago, so scientists are very interested in examining it up close, and the rover is now almost there.
Thirteen years. That is how long NASA’s Opportunity rover has now been exploring Meridiani Planum on Mars; not bad for a robot which was designed with a hoped-for nominal 90-day mission. Today marks the 13th anniversary of the landing of Opportunity, on Jan. 24, 2004 PST (Jan. 25, 2004 UTC). The mission since then has been nothing short of incredible, as Opportunity soon found evidence that Meridiani Planum used to be a much wetter place than it is now. It was a place where microbial life could have existed; whether it actually did or not is still unknown but Opportunity continues to provide more clues as it continues exploring vast sandy plains and mountainous crater rims.
Water on Mars is one of the most talked about and controversial subjects in planetary science. It is now well-known that Mars used to be a much wetter place than it is now, although just how much water there was, and how long it lasted, is still a matter of considerable debate. Direct evidence from rovers, landers, and orbiters, including observations of ancient riverbeds, gullies, and lakes, has shown how at one time Mars was much more Earth-like than it is today. Rovers like Curiosity, Opportunity, and Spirit have actually driven over long-dried-up lakebeds, salty playa lakes, and regions of ancient geothermal activity such as hot steam vents. Now, the Opportunity rover is going to visit another feature not yet explored by any other rover or lander: a gully thought to have been carved by water millions or billions of years ago.
NASA’s current rovers, Curiosity and Opportunity, are continuing to explore their respective regions of Mars, with new findings that are providing yet more clues as to the geological history and potential past habitability of this fascinating world. They have also both just completed significant steps in their journeys and are now entering new and exciting phases of their missions. Both missions have found yet more evidence that the Mars we see today – cold and dry – was once much wetter and potentially habitable, at least for microorganisms.
Almost, but not quite… the Opportunity rover is now driving to another area on the hillside where it is currently located, after attempting to reach a difficult rock target. The rover wasn’t quite able to get close enough to the target to conduct further studies, after driving on the steepest slope ever encountered by any rover so far, on Knudsen Ridge.
NASA’s Curiosity rover on Mars may have been stealing the spotlight in recent years, but the other rover, Opportunity, is still going strong after 12 long years. Opportunity has survived the harsh environment and various challenges for much longer than anyone anticipated, and now is taking on a new task: climbing slopes as steep as 30 degrees while searching for deposits of clay minerals which had already been detected by orbiting spacecraft. The region where Opportunity landed, Meridiani Planum, is mostly flat plains, but now on the rugged edge of the huge Endeavour crater, the rover is becoming something of a mountain climber.
We’ve all seen the commercials for the Energizer Bunny, which keeps going and going and going… it just never seems to stop. This makes for an interesting analogy with the Opportunity rover, which is just now passing its 12th anniversary on Mars. Not just 90 days, as hoped for, but 12 years and counting. Incredible. And in that time, Opportunity has helped to fundamentally alter our understanding of this fascinating world.