Humphrey on the Inside

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

This scene from NASA's Mars rover Opportunity shows "Wharton Ridge," on the western rim of Endeavour Crater. The ridge's name honors the memory of astrobiologist Robert A. Wharton (1951-2012). The ...

Textured rows on the ground in this portion of "Perseverance Valley" are under investigation by NASA's Mars Exploration Rover Opportunity, which used its Navigation Camera to take the component ima...

John Callas has been a leader of NASA's Mars Exploration Rover Project since the project's inception in 2000, and has been the project manager since 2006.

This image shows segments of the western rim of Mars' Endeavour Crater. NASA's Mars rover Opportunity has explored parts of the rim since 2011. The view covers an area about 9 miles wide. It was ta...

This grouping of two test rovers and a flight spare provides a graphic comparison of three generations of Mars rovers developed at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The setting is ...

Researchers used NASA's Mars Exploration Rover Opportunity to find a water-related mineral on the ground that had been detected from orbit, and found it in the dark veneer of rocks on the rim of En...

This close-up view of a target rock called "Last Chance" was acquired by the microscopic imager on the arm of NASA's Mars Exploration Rover Opportunity on March 3, 2004, during the 39th Martian day...

This image from the Mars Exploration Rover Spirit's rear hazard identification camera shows the rover's hind view of the lander platform, its nest for the past 12 sols, or martian days. The rover i...

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

This self-portrait from Opportunity shows dust accumulation on the rover's solar panels as the mission approached its fifth Martian winter.

This before-and-after pair of images of the same patch of ground in front of NASA's Mars Exploration Rover Opportunity 13 days apart documents the arrival of a bright rock onto the scene.

This set of images from NASA’s Mars Reconnaissance Orbiter shows a fierce dust storm is kicking up on Mars, with rovers on the surface indicated as icons.

This Martian scene shows contrasting textures and colors of "Hinners Point," at the northern edge of "Marathon Valley," and swirling reddish zones on the valley floor to the left.

This image from the panoramic camera on NASA's Mars Exploration Rover Opportunity shows a rock called "Chocolate Hills," which the rover found and examined at the edge of a young crater called "Con...

A lunar eclipse, a solar eclipse and Mars has a close encounter with a comet.

NASA's Mars Exploration Rover Opportunity obtained this view from the top of the "Cape Tribulation" segment of the rim of Endeavour Crater. The rover reached this point three weeks before the 11th ...

A forward-looking view of a portion of the "Columbia Hills" captured by Spirit shows the expansive hills ahead. It features "Husband Hill" to the left, "West Spur" in the center, and a talus (rock...

The enhanced-color image taken by the microscopic imager on the Mars Exploration Rover Spirit shows the rock dubbed "Mazatzal" after a portion of its surface was brushed clean by the rover's rock a...

Two generations of Rovers.

This graphic compares atmospheric opacity in different Mars years from the point of view of NASA’s Opportunity rover. 

Rover 2 is driven over staggered ramps to test the suspension's range of motion.

This July 18, 2017, image from the navigation camera (Navcam) on the mast of NASA's Mars Exploration Rover Opportunity provides a look back to the crest of Endeavour Crater's rim after the rover be...

Cumulative driving by NASA's Mars Exploration Rover Opportunity surpassed marathon distance on March 24, 2015, as the rover neared a destination called "Marathon Valley," which is middle ground of ...

In the Payload Hazardous Servicing Facility, technicians remove one of the circuit boards on the Mars Exploration Rover 2 (MER-2).