Today in the history of astronomy, a long-lived rover begins its mission on the surface of the Red Planet.
Among other achievements, Spirit (illustrated here) provided evidence that Mars was geologically active, and once had water favorable for life. Credit: NASA/JPL-Caltech
- The Spirit rover, launched on January 4, 2004, significantly exceeded its initial 90-sol mission exploring Gusev Crater, operating for 20 times its planned duration.
- A 2005 investigation revealed high concentrations of carbonates in “Comanche” rocks, providing the first clear evidence of a past wet, non-acidic Martian environment potentially favorable to life.
- In 2007, an idle wheel suddenly exposed a piece of nearly pure silica, a material on Earth that typically forms near hot springs or acidic steam vents, hinting at potentially habitable regions in Mars’ past.
- After suffering a dust storm in 2009 and becoming stuck in soft mud, Spirit was designated a stationary research platform in January 2010 and ceased communications after its last signal on March 22.
The Spirit rover landed on Mars on January 4, 2004. Like its twin, Opportunity, Spirit was assigned an initial mission of only 90 soles. This extended the lifetime of the mission by more than 20 times, and provided invaluable science in the exploration of the Red Planet. It made its home in Gusev Crater, an ancient impact site and possibly a huge dry lake.
Although Opportunity left it far behind, Spirit still had an impressive science mission lifetime. Highlights included the rover’s 2005 investigation of a group of rocks named “Comanche”. It took nearly five years for scientists to understand what the rover had discovered there, but the result was powerful. The rocks contained high concentrations of carbonates, which can only form in wet, non-acidic environments. Rovers had found signs of acidic water before, but this was their first clear evidence that Mars once had water that could have been favorable for life.
In 2006, one of the Spirit’s front wheels, which was causing trouble to its engineering team, stopped completely. Undaunted, the team instructed Spirit to drive backwards on five wheels, pulling their unresponsive sixth behind them. In this handicapped condition the soul continued successfully for years. Continuing to uncover signs that Mars was once highly active, on December 10, 2007, researchers announced that Spirit’s dragging dead wheels had suddenly cleared a patch of nearly pure silica. On Earth, such material typically forms near hot springs or in areas where acidic steam forces its way through narrow spaces. Both environments on Earth are popular for microbial life, so Martian silica points to habitable regions in Mars’ past.
Spirit spent much of 2008 experiencing massive dust storms, which obscured its solar arrays and reduced the power available for science activities. In 2009, it regained enough energy to resume driving, but on May 1, the rover ran into soft soil in Troy and became stuck in a swamp. The rover team spent more than a year attempting to free Spirit, but to no avail. In January 2010, the rover team declared Spirit a stationary research station. As the Red Planet went into winter, Spirit prepared for lower sunlight levels and the associated reduction in available electricity. But the soul never woke up from its hibernation. The team heard the rover’s last call on March 22.
