- Jezero crater and region
- Water-rich terrain
- Possible channel bringing sediment to the crater
- Jezero crater delta - chemical alteration by water (hi-res)
- Detected clay materials suggest an ancient lake
Feature type | Shield volcano |
---|---|
Coordinates | 8°24′N69°30′E / 8.4°N 69.5°E |
Diameter | ~1 300 km [1] |
Peak | ~2.3 km [2] |
Discoverer | Christiaan Huygens |
Eponym | Gulf of Sidra |
Syrtis Major Planum (formerly Syrtis Major Planitia) is a massive shield volcano in the eastern hemisphere of Mars. A "dark spot" (an albedo feature), Syrtis Major Planum is located in the boundary between the northern lowlands and southern highlands of Mars just west of the impact basin Isidis in the Syrtis Major quadrangle. It was formerly believed to be a plain, and was therefore described as a planitia. Later data from the Mars Global Surveyor revealed that it is actually a broad topographic rise. [2] The dark color of Syrtis Major Planum comes from the basaltic volcanic rock of the region and the relative lack of dust.
The selected landing site for the Mars 2020 mission that includes the rover Perseverance and the helicopter drone Ingenuity was Jezero crater, at 18°51′18″N77°31′08″E / 18.855°N 77.519°E [3] within the region. [4] The northeastern region of Syrtis Major Planum was also considered a potential landing site.
Syrtis Major is centered near at 8°24′N69°30′E / 8.4°N 69.5°E . It extends some 1,500 km (930 mi) north from the planet's equator, and spans 1,000 km (620 mi) from west to east. It is in the Syrtis Major quadrangle. It encompasses a large slope from its western edge at Aeria, dropping 4 km (2.5 mi) to its eastern edge at Isidis Planitia. Most of Syrtis Major has slopes of less than 1°, a much lower inclination than the slopes of the Tharsis shield volcanoes. It has a 350 km × 150 km north–south elongated central depression containing the calderas Nili Patera and Meroe Patera, which are about 2 km deep. [1] [2]
The roughly 2,300-meter high peak of Syrtis Major is located northwest of Nili Patera. The floors of the calderas are unique among large Martian volcanoes as they are not elevated relative to the terrain surrounding Syrtis Major. This may account for the high degree of magmatic evolution and hydrothermal activity seen in Nili Patera. The floor of Nili Patera is the less cratered, and therefore the younger, of the two. While most of the rock is basaltic, dacite has also been detected in Nili Patera. [1] [2]
Satellite gravity field measurements show a positive gravity anomaly centered on the caldera complex, suggesting the presence of a 600 km × 300 km north–south elongated extinct magma chamber below, containing dense minerals (probably mainly pyroxene, with olivine also possible) that precipitated out of magma before eruptions. [5] Crater counts date Syrtis Major to the early Hesperian epoch; it postdates formation of the adjacent Isidis impact basin. [2]
The name Syrtis Major is derived from the classical Roman name Syrtis maior for the Gulf of Sidra on the coast of Libya (classical Cyrenaica).
Syrtis Major was the first documented surface feature of another planet. It was discovered by Christiaan Huygens, who included it in a drawing of Mars in 1659. He used repeated observations of the feature to estimate the length of day on Mars. [6] The feature was originally known as the Hourglass Sea but has been given different names by different cartographers. In 1850s, Angelo Secchi called the feature Atlantic Canale. Later he called it Scorpion and Cook Sea or Cook Canal. [7] .
In Richard Proctor's 1867 map it is called the Kaiser Sea, after Frederik Kaiser of the Leiden Observatory. In 1876, Camille Flammarion called it the Mer du Sablier (French for "Hourglass Sea") when he revised Proctor's nomenclature. The name "Syrtis Major" was chosen by Giovanni Schiaparelli when he created a map based on observations made during Mars' close approach to Earth in 1877. [8] [9]
Syrtis Major was the object of much observation due to its seasonal and long-term variations. This led to theories that it was a shallow sea and later that its variability was due to seasonal vegetation. In the 1960s and 1970s, the Mariner and Viking planetary probes led scientists to conclude that the variations were caused by wind blowing dust and sand across the area. It has many windblown deposits that include light-colored halos or plumose streaks that form downwind of craters. These streaks are accumulations of dust resulting from disruption of the wind by the elevated rims of the craters ('wind shadows'). [1]
Nili Patera is a 50 km diameter caldera at the center of the Syrtis Major Volcanic Complex. [10] It and Meroe Patera located to the south are the primary named calderas within a nested caldera complex developed by multiple eruption and collapse events. [2] In the Northeast quadrant of Nili Patera is a 630 m tall volcanic cone named Nili Tholus, [10] on and around this cone is a light-tone lava flow of chemically evolved lava [11] with multiple occurrences of relict silica sinter deposits created by a formerly active hot spring system. [12]
Nili Patera was the subject of a 2010 study into moving sand dunes and wind ripples. The study showed that dunes are active and that sand ripples are actively migrating on the surface of Mars. [13] A following study also showed that the sand dunes move at about the same flux (volume per time) as dunes in Antarctica. This was unexpected because of the thin air and the winds which are weaker than Earth winds. It may be due to "saltation" - ballistic movement of sand grains which travel further in the weaker Mars gravity.
The lee fronts of the dunes in this region move on average 0.5 meters per year. The selection may be biased here as they only measured dunes with clear lee edges to measure. The ripples move on average 0.1 meters per year. [14]
Arabia Terra is a large upland region in the north of Mars that lies mostly in the Arabia quadrangle, but a small part is in the Mare Acidalium quadrangle. It is densely cratered and heavily eroded. This battered topography indicates great age, and Arabia Terra is presumed to be one of the oldest terrains on the planet. It covers as much as 4,500 km (2,800 mi) at its longest extent, centered roughly at 21°N6°E with its eastern and southern regions rising 4 km (13,000 ft) above the north-west. Alongside its many craters, canyons wind through the Arabia Terra, many emptying into the large northern lowlands of the planet, which borders Arabia Terra to the north.
Terra Sabaea is a large area on Mars. Its coordinates are 2°N42°E and it covers 4,700 kilometres (2,900 mi) at its broadest extent. It was named in 1979 after a classic albedo feature on the planet. Terra Sabaea is fairly large and parts of it are found in five quadrangles: Arabia quadrangle, Syrtis Major quadrangle, Iapygia quadrangle, Ismenius Lacus quadrangle, and Sinus Sabaeus quadrangle.
Isidis Planitia is a plain located within a giant impact basin on Mars, located partly in the Syrtis Major quadrangle and partly in the Amenthes quadrangle. At approximately 1,900 km (1,200 mi) in diameter, it is the third-largest confirmed impact structure on the planet, after the Hellas and Utopia basins. Isidis was likely the last major basin to be formed on Mars, having formed approximately 3.9 billion years ago during the Noachian period, by an impactor around 200 kilometres (120 mi) in diameter. Due to dust coverage, it typically appears bright in telescopic views, and was mapped as a classical albedo feature, Isidis Regio, visible by telescope in the pre-spacecraft era.
The geology of Mars is the scientific study of the surface, crust, and interior of the planet Mars. It emphasizes the composition, structure, history, and physical processes that shape the planet. It is analogous to the field of terrestrial geology. In planetary science, the term geology is used in its broadest sense to mean the study of the solid parts of planets and moons. The term incorporates aspects of geophysics, geochemistry, mineralogy, geodesy, and cartography. A neologism, areology, from the Greek word Arēs (Mars), sometimes appears as a synonym for Mars's geology in the popular media and works of science fiction. The term areology is also used by the Areological Society.
Olympia Undae is a vast dune field in the north polar region of the planet Mars. It consists of a broad "sand sea" or erg that partly rings the north polar plateau from about 120° to 240°E longitude and 78° to 83°N latitude. Stretching about 1,100 km (680 mi) across and covering an area of 470,000 km2, Olympia Undae is the largest continuous dune field on Mars. It is similar in size to the Rub' Al Khali in the Arabian Peninsula, the largest active erg on Earth.
Nili Fossae is a group of large, concentric grabens on Mars, in the Syrtis Major quadrangle. They have been eroded and partly filled in by sediments and clay-rich ejecta from a nearby giant impact crater, the Isidis basin. It is at approximately 22°N, 75°E, and has an elevation of −0.6 km (−0.37 mi). Nili Fossae was on the list of potential landing sites of the Mars Science Laboratory, arriving in 2012, but was dropped before the final four sites were determined. Although not among the last finalists, in September 2015 it was selected as a potential landing site for the Mars 2020 rover, which will use the same design as Curiosity, but with a different payload focused on astrobiology. Nili Fossae is also considered ideal for future human exploration, with the prominent Gavin Crater at 21.43°N, 76.93°E considered the most likely landing zone in Nili Fossae.
Volcanic activity, or volcanism, has played a significant role in the geologic evolution of Mars. Scientists have known since the Mariner 9 mission in 1972 that volcanic features cover large portions of the Martian surface. These features include extensive lava flows, vast lava plains, and the largest known volcanoes in the Solar System. Martian volcanic features range in age from Noachian to late Amazonian, indicating that the planet has been volcanically active throughout its history, and some speculate it probably still is so today. Both Mars and Earth are large, differentiated planets built from similar chondritic materials. Many of the same magmatic processes that occur on Earth also occurred on Mars, and both planets are similar enough compositionally that the same names can be applied to their igneous rocks.
The Noachis quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Noachis quadrangle is also referred to as MC-27.
The Syrtis Major quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Syrtis Major quadrangle is also referred to as MC-13.
The Iapygia quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Iapygia quadrangle is also referred to as MC-21. It was named after the heel of the boot of Italy. That name was given by the Greeks It is part of a region of Italy named Apulia. The name Iapygia was approved in 1958.
The Mare Tyrrhenum quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. This quadrangle is also referred to as MC-22. It contains parts of the regions Tyrrhena Terra, Hesperia Planum, and Terra Cimmeria.
Hesperia Planum is a broad lava plain in the southern highlands of the planet Mars. The plain is notable for its moderate number of impact craters and abundant wrinkle ridges. It is also the location of the ancient volcano Tyrrhena Mons. The Hesperian time period on Mars is named after Hesperia Planum.
Hargraves is a Hesperian-age complex double-layered ejecta impact crater on Mars. It was emplaced near the crustal dichotomy in the vicinity of the Nili Fossae, the Syrtis Major volcanic plains, and the Isidis impact basin, and is situated within the Syrtis Major quadrangle. Hargraves has been the target of focused study because its ejecta apron is particularly well-preserved for a Martian crater of its size. It has been analogized to similar double-layered ejecta blankets on Earth, including that of the Ries impact structure, which was where the conceptual model for how such craters formed was first advanced.
Nili Patera is a dune field on Mars. It is located on top of a lava bed, at the site of an ancient volcano, the Nili Patera caldera of Syrtis Major, near the Martian equator, and it is one of the most active dune fields of Mars. Its location coordinates on Mars are 8.7° N latitude, 67.3° E longitude. It is being actively studied by the HiRISE camera, on board the Mars Reconnaissance Orbiter, at the rate of one image every six weeks. The study of the movement of the dunes provides information regarding wind variation as a function of time and furthers the study of surface erosion characteristics of the Martian landscape. This information can then be used for the development and design of future Mars expeditions. The dunes of the Patera field are of the barchan type and their study by HiRISE was the first one to establish dune and ripple movement of a minimum of 1 metre on Mars. The Patera dune field, was also the first to be investigated using the COSI-Corr software, which was originally developed to analyse the movement of earthbound dunes. The research results from the evidence provided by the monitoring of the Nili Patera field, indicate sand fluxes of the order of several cubic metres per metre per year, similar to the flux observed at the sand dunes of Victoria Valley in Antarctica.
Abalos Undae is a dune field on Mars in the periphery of Planum Boreum, the Martian North pole. It is one of the officially named northern circumpolar dune fields, along with Olympia, Hyperboreae, and Siton Undae, and also one of the densest of the region. Its northernmost boundary is located in the southwest channel that separates the Abalos Colles formation from the main polar ice cap, and from there the dune field extends southwest all the way to the lowlands of Vastitas Borealis.
Siton Undae is one of the largest and densest dune fields in the vicinity of Planum Boreum, the Martian northern polar ice-cap. It is named after one of the classical albedo features on Mars. Its name was officially approved by IAU on 20 March 2007. It extends from latitude 73.79°N to 77.5°N and from longitude 291.38°E to 301.4°E. Its centre is located at latitude 75.55°N, longitude 297.28E (62.72°W), and has a diameter of 222.97 kilometres (138.55 mi).
Ogygis Undae is the only named southern hemisphere dune field on Mars. It is named after one of the classical albedo features on Mars, Ogygis Regio. Its name, which refers to Ogyges, a primeval mythological ruler in ancient Greece, was officially approved by the International Astronomical Union (IAU) on September 17, 2015. It is situated just outside Argyre Planitia, a plain located in the southern highlands of Mars. The dunes of Ogygis Undae extend from latitude −49.94°N to −49.37°N and from longitude 292.64°E to 294.93°E. They are centered at latitude −49.66°N, longitude 293.79°E (66.21°W), and extend approximately 87 km to the east and west from there. Ogygis Undae has an area of 1904 km2, and due to its large size is a primary subject for research on Martian dune morphology and sand composition.
Northeast Syrtis is a region of Mars once considered by NASA as a landing site for the Mars 2020 rover mission. This landing site failed in the competition with Jezero crater, another landing site dozens of kilometers away from Northeast Syrtis. It is located in the northern hemisphere of Mars at coordinates 18°N,77°E in the northeastern part of the Syrtis Major volcanic province, within the ring structure of Isidis impact basin as well. This region contains diverse morphological features and minerals, indicating that water once flowed here. It may be an ancient habitable environment; microbes could have developed and thrived here.
The Thaumasia Plateau is a vast sloping volcanic plain in the western hemisphere of Mars, and is the most extensive component of the Tharsis Rise by area. Syria Planum, Solis Planum, Sinai Planum, and Thaumasia Planum are the constituent sectors of the plateau, which sits between 8 km and 4 km above the surrounding southern highlands. It is bounded by vestigial basement terrains that predate the formation of Tharsis. This area has been proposed to be a drainage basin that sourced the floodwaters forming the outflow channels surrounding Chryse Planitia.