Spirit and Opportunity continue their successful sojourn on Martian soil and both rovers are well on their way to exciting science targets. Spirit has traveled more than 700 meters since its January 3rd landing in the middle of Gusev Crater. The rover is now just 2 kilometers from the Columbia Hills Complex, a destination it could reach in mid to late June. As Spirit approaches the hills, its cameras and spectrometers will be looking for signs of shorelines, layering, or other indicators that water once collected in Gusev to form a lake.
Opportunity continues to make the bigger splash, however. On April 17th, its 82nd day on the Martian surface, the robotic field geologist traversed 141 meters, shattering its own daily distance record by 41 meters. Opportunity is having a relatively easy time navigating the flat, sandy, nearly rockless terrain of Meridiani Planum. It covered more territory in just this one day than the rover Sojourner covered during its entire 83-day mission in 1997.
Opportunity is currently investigating rocks at the edge of a small crater nicknamed Fram. This impact feature lies 450 meters from Eagle Crater, where Opportunity landed on January 25th. The rover's next target is a much larger crater named Endurance, which is only 250 meters away. Endurance is considerably deeper than either Eagle or Fram. With Endurance's wide vertical scale, scientists hope to find a rock outcrop that is thicker than the one Opportunity investigated in Eagle Crater. If Opportunity finds a thicker outcrop, it will give scientists important information about the timescale that water existed on the red planet's surface. Opportunity could reach Endurance by early May.
En route to Fram, Opportunity's spectrometers sniffed a volcanic rock nicknamed Bounce. The spectra revealed striking mineralogical similarities to two Martian meteorites found on Earth, Shergotty (found in India in 1865) and EETA79001 (found in Antarctica in 1979). Orbital images reveal a large impact crater 50 kilometers to the southwest that might be the source of Bounce. This rock has high concentrations of the mineral pyroxene, making it distinctly different from any rock previously studied on Mars.
Both rovers remain in excellent health, and their power and thermal systems continue to operate with minimal deterioration in the frigid Martian environment. Each rover has exceeded its 90-day minimum lifetime and might function into late 2004.