NASA's rover Opportunity visits Victoria Crater, viewed from orbit by the High Resolution Imaging Science Experiment on NASA's Mars Reconnaissance Orbiter in October of 2006. Opportunity is a small dot on the crater's lip, at top right. Opportunity first reached the crater's rim on September 27, 2006. #

Workers put final touches to the two new Mars exploration rovers at NASA's Jet Propulsion Laboratory, on February 10, 2003, in Pasadena, California. The identical robotic explorers will search for evidence of liquid water in two separate areas of the red planet. #

Rover 1 (Opportunity) and lander. A “Martian mechanic” checks beneath the completely deployed Rover 1 lander. Atop the lander is Rover 1 with its wheels and solar arrays in the stowed position. #

On July 7, 2003, at Launch Complex 17-B, Cape Canaveral, Florida, a Delta II Heavy launch vehicle lifts off, carrying the rover Opportunity towards Mars, at 11:18 p.m. EDT. #

On the day of Opportunity's landing—202 days after launch —Pete Theisinger, Project Manager, and Jennifer Trosper, Spirit Mission Manager for Surface Operations react as the first images arrive from the NASA Mars Rover Opportunity. #

California Governor, Arnold Schwarzenegger cheers with Dr. Steve Squyres, principal investigator for Opportunity, and other Mars rovers team members in the Mission Control Center at NASA's JPL in Pasadena, California, on January 24, 2004, following the safe landing of the Opportunity rover on Mars. #

The interior of a crater surrounding the Mars Exploration Rover Opportunity at Meridiani Planum on Mars can be seen in this color image from the rover's panoramic camera, on January 24, 2004. Note the disturbances in the soil from the airbags, which were used to cushion the landing. The airbags are now deflated, seen at bottom. #

An image taken by Opportunity on October 7, 2004, shows a bizarre, lumpy rock informally named Wopmay on the lower slopes of Endurance Crater. Scientists believe the lumps in Wopmay were formed by one of two processes. Either they were caused by the impact that created the football field-sized crater, or they arose when water soaking the rock dried up. #

This image from Opportunity shows an extreme close-up of round, blueberry-shaped formations in the Martian soil near a part of the rock outcrop at Meridiani Planum called Stone Mountain, on February 12, 2004. Scientists studied these curious formations for clues about the soil's formation. #

Clouds appear in the Martian sky above Endurance Crater in this mosaic of frames taken by the navigation camera on NASA's Rover Opportunity at about 9:30 a.m. on the rover's 290th sol (November 16, 2004). These clouds are part of a band that forms near the equator when Mars is near the part of its orbit that is farthest from the Sun. #

This image taken by the panoramic camera onboard Opportunity shows the rover's now-empty lander, the Challenger Memorial Station, at Meridiani Planum, Mars, on February 27, 2004. #

Opportunity gained this view of its own heat shield during the rover's 325th martian day (December 22, 2004). The main structure from the successfully used shield is to the far left. Additional fragments of the heat shield lie in the upper center of the image. The heat shield's impact mark is visible just above and to the right of the foreground shadow of Opportunity's camera mast. #

The remains of the heat shield that protected the rover from temperatures of up to 2,000 degrees Fahrenheit as it made its way through the martian atmosphere. This two-frame mosaic was taken on the rover's 335th martian day, or sol, (January 2, 2005). The view is of the main heat shield debris seen from approximately 10 meters (about 33 feet) away from it. Many rover-team engineers were taken aback when they realized the heat shield had inverted, or turned itself inside out. #

A view of a rock called “Block Island,” the largest meteorite yet found on Mars, comes from the panoramic camera on Opportunity. Analysis of Block Island's composition using the rover's alpha particle X-ray spectrometer confirmed that it is rich in iron and nickel. The rock is about 60 centimeters (2 feet) across. #

The first dust devil that Opportunity observed on Mars. The whirlwind appeared in a routine drive-direction image taken by Opportunity's panoramic camera right after a drive during the 2,301st Martian day, or sol, of the rover's mission on Mars, July 15, 2010. #

The panoramic camera aboard Opportunity acquired this panorama of the “Payson” outcrop on the western edge of Erebus Crater during Opportunity's sol 744 (February 26, 2006). From this vicinity at the northern end of the outcrop, layered rocks are observed in the crater wall, which is about 1 meter (3.3 feet) thick. The view also shows rocks disrupted by the crater-forming impact event and subjected to erosion over time. #

Opportunity's twin rover, Spirit, on its 1,277th sol. Spirit became stuck in soft soil in late 2009, and its last communication with Earth was sent on March 22, 2010. #

This image taken by Opportunity shows a target dubbed “Campbell” on a rock called “MacKenzie” in “Endurance Crater.” Opportunity dug a hole into the target with its rock abrasion tool, then captured this picture with its microscopic imager on sol 184 (July 30, 2004). The image mosaic is about 6 centimeters (2.4 inches) across. #

Opportunity edged close to the top of the “Duck Bay” alcove along the rim of Victoria Crater during the rover's 952nd Martian day, or sol (overnight September 27 to 28), and gained this vista of the crater. The rover's navigation camera took several exposures combined into this mosaic view of the crater's interior. The far side of the crater is about 800 meters (one-half mile) away. The rim of the crater is composed of alternating promontories, rocky points towering approximately 70 meters (230 feet) above the crater floor, and recessed alcoves, such as Duck Bay. #

An example of spectacular cross-bedding in Victoria crater on the outcrops at Cape St. Mary, which is an approximately 15-meters-(45-feet) high promontory located along the western rim of Victoria crater and near the beginning of the rover's traverse around the rim. These Pancam super-resolution images have allowed scientists to discern that the rocks at Victoria Crater once represented a large dune field that migrated across this region. #

A photo from June 28, 2007 of tracks left by Opportunity as it traveled along the rim of Victoria Crater can be seen clearly in this image taken by the HiRISE camera on NASA's Mars Reconnaissance Orbiter spacecraft. #

Opportunity climbs out of Victoria Crater on August 28, 2008, following the tracks it had made when it descended into the 800-meter-diameter (half-mile-diameter) bowl nearly a year earlier. The rover's navigation camera captured this view back into the crater just after finishing a 6.8-meter (22-foot) drive that brought Opportunity out onto level ground during the mission's 1,634th Martian day, or sol. #

This view from Opportunity shows the tracks left by a drive executed with more onboard autonomy than has been used on any other drive by a Mars rover. Opportunity made the curving, 15.8-meter (52-foot) drive during its 1,160th Martian day, or sol (April 29, 2007). It was testing a navigational capability called “Field D-star,” which enables the rover to plan optimal long-range drives around any obstacles in order to travel the most direct safe route to the drive's designated destination. Victoria Crater is in the background, at the top of the image. #

Opportunity catches its own late-afternoon shadow in a view eastward across Endeavour Crater on Mars. The rover used a panoramic camera between about 4:30 and 5:00 p.m. local Mars time to record images taken through different filters and combined into this mosaic view. The view is presented in false color to make some differences between materials easier to see, such as the dark sandy ripples and dunes on the crater's distant floor. #

This image, taken by the microscopic imager, shows a geological region of the rock outcrop at Meridiani Planum, Mars dubbed “El Capitan.” The area in this image, taken on Sol 28 of the Opportunity mission, is 1.5 centimeters (0.6 inches) across. Round particles the size of BBs are embedded in the outcrop. From shape alone, these spherules might be formed from volcanic eruptions, from lofting of molten droplets by a meteor impact, or from accumulation of minerals coming out of solution inside a porous, water-soaked rock. Opportunity's observations that the spherules are not concentrated at particular layers in the outcrop weigh against a volcanic or impact origin, but do not completely rule out those origins. #

An elongated crater called “Spirit of St. Louis,” with a rock spire in it, dominates this scene from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity.This scene from late March 2015 shows a shallow crater called Spirit of St. Louis, about 110 feet (34 meters) long and about 80 feet (24 meters) wide, with a floor slightly darker than surrounding terrain. The rocky feature toward the far end of the crater is about 7 to 10 feet (2 to 3 meters) tall, rising higher than the crater's rim. #