NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, Spirit and Opportunity, exploring the planet Mars. It began in 2003 with the launch of the two rovers to explore the Martian surface and geology; both landed on Mars at separate locations in January 2004. Both rovers far outlived their planned missions of 90 Martian solar days: MER-A Spirit was active until March 22, 2010, while MER-B Opportunity was active until June 10, 2018.
Gusev is a crater on the planet Mars and is located at 14.5°S 175.4°E and is in the Aeolis quadrangle. The crater is about 166 kilometers in diameter and formed approximately three to four billion years ago. It was named after Russian astronomer Matvey Gusev (1826–1866) in 1976.
Meridiani Planum is a plain located 2 degrees south of Mars's equator, in the westernmost portion of Sinus Meridiani. It hosts a rare occurrence of gray crystalline hematite. On Earth, hematite is often formed in hot springs or in standing pools of water; therefore, many scientists believe that the hematite at Meridiani Planum may be indicative of ancient hot springs or that the environment contained liquid water. The hematite is part of a layered sedimentary rock formation about 200 to 800 meters thick. Other features of Meridiani Planum include volcanic basalt and impact craters.
Spirit, also known as MER-A or MER-2, is a Mars robotic rover, active from 2004 to 2010. Spirit was operational on Mars for 2208 sols or 3.3 Martian years. It was one of two rovers of NASA's Mars Exploration Rover Mission managed by the Jet Propulsion Laboratory (JPL). Spirit landed successfully within the impact crater Gusev on Mars at 04:35 Ground UTC on January 4, 2004, three weeks before its twin, Opportunity (MER-B), which landed on the other side of the planet. Its name was chosen through a NASA-sponsored student essay competition. The rover got stuck in a "sand trap" in late 2009 at an angle that hampered recharging of its batteries; its last communication with Earth was on March 22, 2010.
Sinus Meridiani is an albedo feature on Mars stretching east-west just south of the planet's equator. It was named by the French astronomer Camille Flammarion in the late 1870s.
Endurance is an impact crater lying situated within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars. This crater was visited by the Opportunity rover from May until December 2004. Mission scientists named the crater after the ship Endurance that sailed to the Antarctic through the Weddell Sea during the ill-fated 1914-1917 Imperial Trans-Antarctic Expedition, considered to be the last expedition of the Heroic Age of Antarctic Exploration organized by Ernest Shackleton.
Eagle is a 22-metre long impact crater located on the Meridiani Planum extraterrestrial plain, situated within the Margaritifer Sinus quadrangle (MC-19) portion of the planet Mars. The Opportunity rover came to rest inside Eagle crater when it landed in 2004. Scientists were delighted that the rover landed there, as the crater contains rocky outcroppings that helped prove that Meridiani was once an ocean floor.
Victoria is an impact crater on Mars located at 2.05°S, 5.50°W in the Meridiani Planum extraterrestrial plain, lying situated within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars. This crater was first visited by the Mars Exploration Rover Opportunity. It is roughly 800 metres (2,600 ft) wide, nearly eight times the size of the crater Endurance, visited by Opportunity from sols 951 to 1630. It is informally named after Victoria – one of the five Spanish ships of Ferdinand Magellan and the first ship to circumnavigate the globe – and formally named after Victoria, Seychelles. Along the edges of the crater are many outcrops within recessed alcoves and promontories, named for bays and capes that Magellan discovered.
NASA's 2003 Mars Exploration Rover Mission has amassed an enormous amount of scientific information related to the Martian geology and atmosphere, as well as providing some astronomical observations from Mars. This article covers information gathered by the Opportunity rover during the initial phase of its mission. Information on science gathered by Spirit can be found mostly in the Spirit rover article.
In geology, cross-bedding, also known as cross-stratification, is layering within a stratum and at an angle to the main bedding plane. The sedimentary structures which result are roughly horizontal units composed of inclined layers. The original depositional layering is tilted, such tilting not being the result of post-depositional deformation. Cross-beds or "sets" are the groups of inclined layers, which are known as cross-strata.
In geology, ripple marks are sedimentary structures and indicate agitation by water or wind.
Beagle is a crater lying within the Margaritifer Sinus quadrangle (MC-19) portion of the planet Mars, the crater is one of multiple topographical depressions within the Meridiani Planum extraterrestrial plain, which was explored by the Opportunity rover. It was located by the rover in images taken on sol 855, 310 metres (1,107 ft) away. It is on the edge of the much larger ejecta blanket surrounding the crater Victoria, named the Victoria Annulus. This impact crater was named in honor of HMA Beagle of the Royal Navy, ordered in February 1817, which carried Charles Darwin on his voyage round the world.
El Capitan is a layered rock outcrop found within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars, this geological outcrop was first discovered and observed by the Mars Exploration Rover Opportunity in February 2004. The rock outcrop was named for El Capitan, a topographical mountain lying within the state, Texas.
Becquerel is a 167 km-diameter crater at 22.1°N, 352.0°E on Mars, in Arabia Terra in Oxia Palus quadrangle. It is named after Antoine H. Becquerel.
Sedimentary structures include all kinds of features in sediments and sedimentary rocks, formed at the time of deposition.
The Margaritifer Sinus quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Margaritifer Sinus quadrangle is also referred to as MC-19. The Margaritifer Sinus quadrangle covers the area from 0° to 45° west longitude and 0° to 30° south latitude on Mars. Margaritifer Sinus quadrangle contains Margaritifer Terra and parts of Xanthe Terra, Noachis Terra, Arabia Terra, and Meridiani Planum.
To date, interplanetary spacecraft have provided abundant evidence of water on Mars, dating back to the Mariner 9 mission, which arrived at Mars in 1971. This article provides a mission by mission breakdown of the discoveries they have made. For a more comprehensive description of evidence for water on Mars today, and the history of water on that planet, see Water on Mars.
The composition of Mars covers the branch of the geology of Mars that describes the make-up of the planet Mars.
Opportunity is a robotic rover that was active on the planet Mars from 2004 to 2018. Launched on July 7, 2003, Opportunity landed on Mars' Meridiani Planum on January 25, 2004 at 05:05 Ground UTC, three weeks after its twin Spirit (MER-A), also part of NASA's Mars Exploration Rover Mission, touched down on the other side of the planet. While Spirit became immobile in 2009 and ceased communications in 2010, Opportunity exceeded its planned 90 sol duration of activity by 18 years, 41 days. Opportunity continued to move, gather scientific observations, and report back to Earth until 2018. What follows is a summary of events during its continuing mission.
