Spirit drove through the basin south of "Husband Hill," mainly driving over sand and dune deposits until it came across this spectacul...

Spirit discovered this remarkable patch of bright, loose soil while driving toward "Home Plate" along the floor of the basin south of ...

This view combines frames taken by the panoramic camera on Opportunity's 652nd through 663rd Martian days, or sols (Nov. 23 to Dec. 5, 2005), ...

In this selfie, Spirit shows her solar panels gleaming in the Martian sunlight and carrying only a thin veneer of dust two years after the rov...

This is the Opportunity "Erebus Rim" panorama, acquired on sols 652 to 663 (Nov. 23 to Dec. 5, 2005 ), as Opportunity was exploring sa...

This synthetic image of NASA's Opportunity Mars Exploration Rover inside Endurance Crater was produced using "Virtual Presence in Space...

This synthetic image of NASA's Opportunity Mars Exploration Rover inside Endurance Crater was produced using "Virtual Presence in Space...

This synthetic image recreates what Opportunity might look like in Endurance Crater. Produced using "Virtual Presence in Space" techno...

In late November 2005 while descending "Husband Hill," Spirit took the most detailed panorama so far of the "Inner Basin," one...

This image shows a portion of the rim of "Erebus Crater" in the Meridiani Planum region of Mars.

Hundreds of images taken by Spirit were combined into this 360-degree view of "Husband Hill Summit" and the rover's deck.

These images of a sand "ripple" were acquired by Opportunity using its panoramic camera on sol 644 and its navigation camera on sol 645.

This synthetic image of the Spirit Mars Exploration Rover in the "Columbia Hills" was produced using "Virtual Presence in Space...

This synthetic image of the Spirit Mars Exploration Rover on top of a rock called "Jibsheet" was produced using "Virtual Presence ...

This synthetic image of the Spirit Mars Exploration Rover on the flank of "Husband Hill" was produced using "Virtual Presence in S...

Locations of landers and rovers on Mars.

This false-color panoramic image, taken on martian day, or sol, 561 (Aug. 22, 2005) by the Opportunity rover, shows the nature of the outcrop ...

More than 1.5 years into their exploration of Mars, both of NASA's Mars Exploration Rovers continue to send a cornucopia of images to Earth.

This image hows several dust devils moving from right to left across a plain inside Mars' Gusev Crater, as seen from the vantage point of NASA...

This panoramic image, dubbed "Rub al Khali," was taken by Opportunity on the plains of Meridiani during the rover's 456th to 464th sol...

If a human with perfect vision donned a spacesuit and stepped onto the martian surface, the view would be as clear as this sweeping panorama t...

Opportunity's wheels dug more than 10 centimeters (4 inches) deep into the soft, sandy material of a wind-shaped ripple in Mars' Meridiani Pla...

A portion of an exposure of bedrock dubbed "Larry's Outcrop" shows little layering in this view, in contrast to nearby outcrops called...

This is a zoomed in view on Spirit 's "Lookout" panorama on the drive up to the summit "Husband Hills."

This is the Spirit panoramic camera's "Lookout" panorama, acquired on the rover's 410th to 413th martian days, or sols (Feb. 27 to Mar...

Gazing across the landscape of the "Columbia Hills" in Gusev Crater on Mars, scientists saw hints of tilted rock layers across the are...

These two images from 10 days apart show that dust was removed from the panoramic camera's calibration target on NASA's Mars Exploration Rover...

This image shows rocky debris and dust, which planetary scientists call "regolith" or "soil," that has been churned up by the ...

Opportunity used its panoramic camera to take the images combined into this mosaic view of the rover.

This view captured by Spirit called "Legacy" panorama, combines images taken between the landing site and the rim of "Bonnevile Cr...

NASA's Mars Exploration Rover Spirit took this image of the region near "Husband Hill."

This stunning image features the heat shield impact site of NASA's Mars Exploration Rover Opportunity.

Since landing on Mars a year ago, NASA's pair of six-wheeled geologists have been constantly exposed to martian winds and dust.

Opportunity found an iron meteorite on Mars, the first meteorite of any type ever identified on another planet.

This image from Opportunity's panoramic camera features the remains of the heat shield that protected the rover from temperatures of up to 2,0...

Opportunity captured this view of "Burns Cliff" after driving right to the base of this southeastern portion of the inner wall of "...

This stunning image mosaic of the "Columbia Hills" is the first 360-degree panorama taken by Spirit after arriving at the hills.

At a rock called "Clovis," the rock abrasion tool on Spirit cut a 9-millimeter (0.35-inch) hole. To the right of the drill hole is a...

This false-color image taken by Spirit shows a group of darker rocks dubbed "Toltecs," lying to the southeast of the rover's position....

As NASA's Mars Exploration Rover Opportunity creeps farther into "Endurance Crater," the dune field on the crater floor appears even m...

As Opportunity crept farther into "Endurance Crater," the dune field on the crater floor appears even more dramatic, as seen in this f...

As Opportunity crept farther into "Endurance Crater," the dune field on the crater floor appeared even more dramatic.

The rock abrasion tool on NASA's Mars Exploration Rover Spirit ground two holes in a relatively soft rock called "Wooly Patch" near th...

This self-portrait of NASA's Mars Exploration Rover Opportunity comes courtesy of the Sun and the rover's front hazard-avoidance camera.

This view from the Mars Exploration Rover Opportunity's panoramic camera is a false-color composite rendering of the first seven holes that th...

The pointy features, dubbed "Razorback," in this image may only be a few centimeters high but they generate major scientific interest.

This image is an approximately true color rendering of the slope of "Endurance Crater," which the Opportunity rover explored in 2004.

This false-color image highlights mysterious and sparkly dust-like material that is created when the soil in this region is disturbed.

This close-up image taken by Spirit highlights the nodular nuggets that cover the rock dubbed "Pot of Gold."

This 360-degree panorama shows "Endurance Crater" and the surrounding plains of Meridiani Planum.