Top 10 Discoveries by Mars Rovers Spirit & Opportunity: A Scientist's View
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Dust Devils, Ancient Habitable Environments & MoreNASA's Opportunity Mars rover has now been exploring the Red Planet for a decade. The golf-cart-size robot landed on the night of Jan. 24, 2004, three weeks after its twin, Spirit.
Spirit and Opportunity were originally tasked with 90-day missions that called for them to search for signs of past water activity on the Red Planet. Both rovers far outlasted their warranties; Spirit was declared dead in 2011, and Opportunity continues roving to this day. And they both made big discoveries that have fundamentally reshaped scientists' understanding of Mars and its environmental history.
Rover deputy principal investigator Ray Arvidson, of Washington University in St. Louis, submitted a Spirit and Opportunity Top 10 list to SPACE.com to mark the mission's 10 years of Mars exploration in 2014. To be clear, these are Arvidson's personal opinions, not a consensus of the mission team.
FIRST STOP: Mars Atmosphere Dynamics
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Modern Waters, Part 2Spirit: Ferric sulfates were moved down the soil column by modern waters at Troy, Husband Hill, Gusev Crater. [Related: Trapped Mars Rover Finds Signs of Buried Martian Water in Recent Past]
NEXT: Water Meets Hot Rocks
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Water Interacting with Hot RockSpirit: Iron-magnesium carbonates at the Comanche outcrop, Husband Hill, Gusev Crater, showing that water interacted with magma.
NEXT: Ancient Hydrothermal System
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An Ancient Hydrothermal SystemSpirit: Opaline silica at Home Plate, Gusev Crater, formed in volcanic fumeroles and/or hydrothermal vents. Again, showing that water was interacting with magma. [Related: Habitable Hotspots on Mars? Volcano Vents May Be Signs]
NEXT: Wind-Blown Ripples
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A Habitable Environment Long AgoOpportunity: The rover has found evidence that ancient Mars may have been habitable for millions of years. At the rim of Endeavour Crater, Cape York; the rover discovered ferric and aluminous smectite clays in finely layered Matijevic formation rocks that pre-exist the Endeavour impact event. Alteration in moderately acidic and reducing waters, perhaps mildly oxidizing for ferric smectites. These are the oldest rocks examined by Opportunity (roughly 4 billion years old), and they were exposed to waters much more habitable than the waters that led to the Burns formation. [Video: Mars Could Have Supported Life, NASA Finds]
NEXT: Ancient Acidic Lakes
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Ancient Acidic LakesOpportunity: The Meridiani plains' Burns formation as sulfate-rich sandstones with hematitic concretions formed in ancient acidic and oxidizing shallow lakes and reworked into sand dunes and cemented by rising groundwaters.
More Mars Rover Reading:
- Latest News About Mars Rovers Opportunity and Spirit
- Latest Mars Rover Photos from Spirit and Opportunity
- How NASA's Mars Rovers Spirit and Opportunity Work (Infographic)
- Rover Tracks on Mars | SPACE.com Video Show
- 10 Amazing Mars Discoveries by Spirit & Opportunity
- Mars Rover's '90 Day Mission' Now In 10th Year | Video
- Occupy Mars: History of Robotic Red Planet Missions (Infographic)
- Mars Explored: Landers and Rovers Since 1971 (Infographic)