Meridiani Planum
Encyclopedia
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
' equator (centered at 0.2°N 357.5°W), in the westernmost portion of Terra Meridiani. It hosts a rare occurrence of gray crystalline hematite
Hematite
Hematite, also spelled as haematite, is the mineral form of iron oxide , one of several iron oxides. Hematite crystallizes in the rhombohedral system, and it has the same crystal structure as ilmenite and corundum...
. On Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
, hematite is often formed in hot spring
Hot spring
A hot spring is a spring that is produced by the emergence of geothermally heated groundwater from the Earth's crust. There are geothermal hot springs in many locations all over the crust of the earth.-Definitions:...
s or in standing pools of water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
; 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
Sedimentary rock
Sedimentary rock are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....
formation about 200 to 800 meters thick. Other features of Meridiani Planum include volcanic
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
and impact crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
s.
Mars rover Opportunity
In 2004, Meridiani Planum was the landing site for the second of NASANASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
's two Mars Exploration Rovers, named Opportunity
Opportunity rover
Opportunity, MER-B , is a robotic rover on the planet Mars, active since 2004. It is the remaining rover in NASA's ongoing Mars Exploration Rover Mission...
. It had also been the target landing site for Mars Surveyor 2001 Lander
Mars Surveyor 2001 Lander
The NASA Mars Surveyor 2001 Lander was a planned Mars probe which was canceled in May 2000 in the wake of the failures of the Mars Climate Orbiter and Mars Polar Lander missions in late 1999...
, which was cancelled after the failures of the Mars Climate Orbiter
Mars Climate Orbiter
The Mars Climate Orbiter was a 338 kilogram robotic space probe launched by NASA on December 11, 1998 to study the Martian climate, atmosphere, surface changes and to act as the communications relay in the Mars Surveyor '98 program, for Mars Polar Lander...
and Mars Polar Lander
Mars Polar Lander
The Mars Polar Lander, also referred to as the Mars Surveyor '98 Lander, was a 290-kilogram robotic spacecraft lander, launched by NASA on January 3, 1999, to study the soil and climate of Planum Australe, a region near the south pole on Mars, as part of the Mars Surveyor '98 mission...
missions.
Results from Opportunity indicate that its landing site was once saturated for a long period of time with liquid water, possibly of high salinity and acidity. Features that suggest this include cross-bedded sediments, the presence of many small spherical pebbles that appear to be concretion
Concretion
A concretion is a volume of sedimentary rock in which a mineral cement fills the porosity . Concretions are often ovoid or spherical in shape, although irregular shapes also occur. The word 'concretion' is derived from the Latin con meaning 'together' and crescere meaning 'to grow'...
s, vug
Vug
Vugs are small to medium-sized cavities inside rock that may be formed through a variety of processes. Most commonly cracks and fissures opened by tectonic activity are partially filled by quartz, calcite, and other secondary minerals. Open spaces within ancient collapse breccias are another...
s inside rocks, and the presence of large amounts of magnesium sulfate
Magnesium sulfate
Magnesium sulfate is a chemical compound containing magnesium, sulfur and oxygen, with the formula MgSO4. It is often encountered as the heptahydrate epsomite , commonly called Epsom salt, from the town of Epsom in Surrey, England, where the salt was distilled from the springs that arise where the...
and other sulfate-rich minerals such as jarosite
Jarosite
Jarosite is a basic hydrous sulfate of potassium and iron with a chemical formula of KFe3+362. This sulfate mineral is formed in ore deposits by the oxidation of iron sulfides...
.
Craters within Meridiani Planum
- Airy CraterAiry (Martian crater)Airy is an impact crater on Mars, named in honor of the British Astronomer, Royal Sir George Biddell Airy . The crater is approximately 40 kilometers in diameter and is located at 0.1°E 5.1°S in the Meridiani Planum region. The much smaller crater Airy-0, which defines the location of Mars' prime...
– 40 kilometre (km) in diameter and about 375 km west-southwest of OpportunityOpportunity roverOpportunity, MER-B , is a robotic rover on the planet Mars, active since 2004. It is the remaining rover in NASA's ongoing Mars Exploration Rover Mission...
- Airy-0Airy-0Airy-0 is a crater on Mars whose location defines the position of the prime meridian of that planet. It is about across and lies within the larger crater Airy in the region Sinus Meridiani....
– Lies within the Airy crater, and defines the Martian Prime MeridianPrime MeridianThe Prime Meridian is the meridian at which the longitude is defined to be 0°.The Prime Meridian and its opposite the 180th meridian , which the International Date Line generally follows, form a great circle that divides the Earth into the Eastern and Western Hemispheres.An international...
- Airy-0
- Argo CraterArgo (crater)Argo is a crater located in the Meridiani Planum, on Mars, that was visited by the Opportunity rover approximately on its 365th Martian sol. The crater is located approximately south of the heat shield and Heat Shield Rock.-External links:*...
– Visited by Opportunity - Beagle CraterBeagle (crater)This article is about the crater on Mars. For other uses, see Beagle .Beagle is a crater on Mars in Meridiani Planum which was explored by the Opportunity rover. It was located by the rover in images taken on sol 855 , 310 metres away...
– Visited by Opportunity - Beer CraterBeer (Martian crater)Beer is a crater on Mars named in honor of the German astronomer Wilhelm Beer. It is located at 14.4°S 351.8°E .Beer and collaborator Johann Heinrich Mädler produced the first reasonably good maps of Mars in the early 1830s. When doing so, they selected a particular feature for the prime meridian...
- Eagle CraterEagle (crater)Eagle is a 22-metre impact crater located on Mars on Meridiani Planum. The Opportunity rover came to rest inside Eagle crater when it landed in 2004...
– Landing site of Opportunity and 30 metre diameter - Emma Dean CraterEmma Dean (crater)Emma Dean is a small impact crater in Meridiani Planum on Mars that was visited by the Opportunity rover from sols 929 to 943. The much larger crater Victoria lies about 100m to the east....
– Visited by Opportunity - Endurance CraterEndurance (crater)Endurance is an impact crater on Mars that 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 in an exploration voyage organized by Ernest Shackleton.The rover entered the crater interior on...
– Visited by Opportunity - Erebus CraterErebus (crater)Erebus is a crater on Mars visited by the Opportunity rover on the way to the much larger crater Victoria. It is named after the polar exploration vessel HMS Erebus...
– Visited by Opportunity - Mädler CraterMädler (Martian crater)Mädler is a crater on Mars named in honor of the German astronomer Johann Heinrich Mädler. It is located at 2.7°E 10.7°S.Mädler and collaborator Wilhelm Beer produced the first reasonably good maps of Mars in the early 1830s. When doing so, they selected a particular feature for the prime meridian...
- Santa Maria CraterSanta Maria (crater)Santa Maria is an impact crater on Mars located at 2.172°S, 5.445°W in Meridiani Planum, visited by the Mars Exploration Rover Opportunity. It sits north west of the much larger Endeavour crater. It is about 80-90 meters across.-Exploration:...
- Visited by Opportunity - Victoria CraterVictoria (crater)Victoria is an impact crater on Mars located at 2.05°S, 5.50°W in Meridiani Planum, visited by the Mars Exploration Rover Opportunity. It is roughly 730 metres wide, nearly eight times the size of the crater Endurance, visited by Opportunity from sols 951 to 1630...
– Visited by Opportunity and 750 metre diameter - Vostok CraterVostok (crater)Vostok is a crater on Mars that was reached by the rover Opportunity on sol 399 . Vostok is located roughly 1200 meters south of Endurance in Meridiani Planum...
– Visited by Opportunity