NASA's twin rovers, Spirit and Opportunity, were slated for a three month life. Both far exceeded that. Spirit is now dead but Opportunity continues its trek of exploration over Mars since 2004. The images it continues to return are staggering.
Mars's True Colors
This image from Opportunity is as close as the researchers can get to the true colors on the Red Planet. It is a collage of images taken through a combination of filters. The rover was on its way to Endurance crater at this point in its travels.
The Dunes at Endurance
Sand dunes are prevalent all over Mars's surface. These at Endurance crater, encountered early in Opportunity's travels, appear like ocean waves. This also is an image formed from several taken through various filters to give a close-to-true color view of the Red Planet.
Endurance is just a short jaunt from Opportunity's landing site, but it took the rover almost a year to reach the area at its slow crawl, well under a mile an hour, with stops along the way.
Opportunity at Work
Opportunity used its rock abrasion tool on a rock named "Gagarin" during March 10 and 11, 2005. This false-color image shows the circular mark created where the tool exposed the interior of the rock at a target called "Yuri." The circle is about 1.8 inches in diameter. Gagarin is at the edge of a highly eroded, small crater that was named "Vostok" for the spacecraft that carried Cosmonaut Yuri Gagarin on the first human spaceflight on April 12, 1961.
Meteors on Mars
Opportunity found an iron meteorite on Mars, the first meteorite of any type ever identified on another planet. The pitted, basketball-size object is mostly made of iron and nickel. Readings from spectrometers on the rover determined that composition. There was no clue as to how long it had been lying on the surface.
By 2007, Opportunity had made its way to an interesting crater the team named Victoria, about 6.2 miles from its landing site. The rover was sent into this crater to explore its rim and rock formations. The cliff in this image is named Cape St. Vincent. It is a promontory approximately 39 feet tall on the northern rim. Layers seen in Cape St. Vincent have proven to be among the best examples of meter scale cross-bedding observed on Mars to date. Cross-bedding is a geologic term for rock layers which are inclined relative to the horizontal and which are indicative of ancient sand dune deposits. Scientists have determined that the rocks at Victoria Crater once represented a large dune field, like the Sahara desert on Earth, and that this dune field migrated with an ancient wind flowing from the north to the south across the region. Other rover chemical and mineral measurements have shown that many of the ancient sand dunes studied in Meridiani Planum (the plain on which the rover landed) were modified by surface and subsurface liquid water long ago!
A New Goal
After Victoria, the rover team looked for a new goal for their amazing vehicle. They found it far on the horizon, Endeavour, a crater 13 miles in diameter, about 25 times wider than Victoria crater. Opportunity snapped this image of the crater rim April 28, 2010.
Visible is an outcrop of rocks at the foot of the rover and beyond these rocks are rippled dunes, which are about 8 inches tall. The west rim of Endeavour, about 8 miles away, appears on the left on the horizon. (Remember, Mars is smaller than Earth, so the horizon is not as far.) The rim of a smaller, more-distant crater, Iazu, 4 miles in diameter and about 22 miles away, is on the far right. On the horizon in between is a blanket of material ejected from the impact that created Iazu crater, and darker features that are portions of the west and southwest rim of Endeavour.
Opportunity began a marathon from Victoria to Endeavour in September 2008 after spending two years exploring Victoria.
Along the Way
A panoramic view of the Santa Maria crater, along the way to Endeavour. Santa Maria is a small crater with a diameter of about 300 feet. It exhibits interesting rock formations the rover team wanted to investigate on the drive to the ultimate destination, which can be seen on the horizon.
This is a false color image designed to show the different types of rocks and soils in the crater.
The Long Trek
Opportunity's path from its landing site inside Eagle crater, at the upper left end of the track to a point about 2.2 miles from the rim of Endeavour crater earlier this year. The yellow line shows the rovers path, and its stops are notated.This view was taken by the Mars Reconnaisance Orbiter
Endeavour crater has been the rover team's destination for Opportunity since the rover finished exploring Victoria crater in August 2008. In honor of Opportunity's rover twin, the team has chosen "Spirit Point" as the name for the site on Endeavour's rim targeted for Opportunity's arrival at Endeavour. Spirit, which worked halfway around Mars from Opportunity for more than six years, ended communication in March 2010.
Opportunity reached the point in its traverse indicated on this map on May 27, 2011. By that time, Opportunity had driven a total of 18.58 miles
The western rim of Endeavour has a series of ridges. Spirit Point is the southern edge of a ridge called "Cape York." Farther south on the rim, a ridge called "Cape Tribulation" offers exposures identified from orbit as clay minerals.
Opportunity approaches its goal. The closest of the distant ridges visible along the Endeavour rim is informally named "Solander Point." Opportunity may investigate that area in the future. The rover's first destination on the rim, called "Spirit Point" in tribute to Opportunity's now-inactive twin, Spirit, is to the left (north) of this scene.
The lighter-toned rocks closer to the rover in this view are similar to the rocks Opportunity has driven over for most of the mission. However, the darker-toned and rougher rocks just beyond that might be a different type for the rover to investigate.
The ground in the foreground is covered with iron-rich spherules, nicknamed "blueberries," which Opportunity has observed frequently since the first days after landing. They are about 0.2 inch (5 millimeters) or more in diameter.
Opportunity arrived at the rim of Endeavour crater on Aug. 9, 2011. It had travelled more than 13 miles for almost three years since leaving Victoria crater in August 2008.
This view shows the "Spirit Point" area of the rim and another small crater, "Odyssey" on the rim. The interior of Endeavour can be see beyond.
A Strange Rock
This rock, named "Tisdale 2" was the first rock Opportunity examined in detail on the rim of Endeavour crater. It has textures and composition unlike any rock the rover examined during its first 90 months on Mars. Its characteristics are consistent with the rock being a breccia -- a type of rock created by broken fragments of older rocks fused together
Tisdale 2 is about 12 inches high. The black vertical line superimposed on the image shows the work plane of Opportunity's robotic arm when the arm placed the rover's microscopic imager and alpha particle X-ray spectrometer over the rock.
This is a false color image to highlight the varied types of minerals in the rock.
Another Unique Rock
"Chester Lake" is not a lake bed, but a rock outcrop. This false color image emphasizes differences among materials in the rock and soil. The images were taken on Sept. 7, 2011.
The Chester Lake rock is about 3 feet across. It lies on the southeastern side of a low ridge called "Cape York," which forms a portion of the western rim of Endeavour crater.
Chester Lake differs from "Tisdale 2," which is a boulder excavated during an impact event that produced a small crater on the rim. Both rocks appear to be breccia.
Opportunity continues its investigation of Chester Lake, and will continue to explore Endeavour crater. More incredible images from Mars are sure to be forthcoming.