Topographic map of the location of Trouvelot Crater
|Quadrangle||Oxia Palus quadrangle|
|Eponym||Étienne Léopold Trouvelot, a French astronomer (1827–1895)|
Trouvelot is a crater on Mars, located in the Oxia Palus quadrangle at 16.2° north latitude and 13.1° west longitude near the crustal dichotomy in the circum-Chryse region. It is roughly located along the dichotomy between Arabia Terra to the northeast and the southernmost of the circum-Chryse outflow channels to the southwest. Trouvelot crater measures approximately 149 kilometers in diameter and was named after Étienne Léopold Trouvelot, a French astronomer (1827–1895). The naming was adopted by IAU's Working Group for Planetary System Nomenclature in 1973.
Impact craters generally have a rim with ejecta around them, in contrast volcanic craters usually do not have a rim or ejecta deposits. As craters get larger (greater than 10 km in diameter) they usually have a central peak. The peak is caused by a rebound of the crater floor following the impact.
There is a part of Trouvelot that displays many thin, light-toned layers; these may be evidence that a lake was present in the past. Many craters once contained lakes.Because some crater floors show deltas, we know that water had to be present for some time. Dozens of deltas have been spotted on Mars. Deltas form when sediment is washed in from a stream entering a quiet body of water. It takes a bit of time to form a delta, so the presence of a delta is exciting; it means water was there for a time, maybe for many years. Primitive organisms may have developed in such lakes; hence, some craters may be prime targets for the search for evidence of life on the Red Planet.
Many places on Mars show rocks arranged in layers. Rock can form layers in a variety of ways. Volcanoes, wind, or water can produce layers.Sometimes the layers are of different colors. Light-toned rocks on Mars have been associated with hydrated minerals like sulfates. The Mars Rover Opportunity examined such layers close-up with several instruments. Some layers are probably made up of fine particles because they seem to break up into fine dust. Other layers break up into large boulders, so they are probably much harder. Basalt, a volcanic rock, is thought to be present in the layers that form boulders. Basalt has been identified on Mars in many places. Instruments on orbiting spacecraft have detected clay (also called phyllosilicate) in some layers. Recent research with an orbiting near-infrared spectrometer, which reveals the types of minerals present based on the wavelengths of light they absorb, found evidence of layers of both clay and sulfates in many places, especially craters. This is exactly what would appear if a large lake had slowly evaporated. Moreover, since some layers contain gypsum, a sulfate which forms in relatively fresh water, life could have formed in some craters.
Scientists are excited about finding hydrated minerals such as sulfates and clays on Mars because they are usually formed in the presence of water.Places that contain clays and/or other hydrated minerals would be good places to look for evidence of life.
Holden is a 140 km wide crater situated within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars, located with the southern highlands. It is named after American astronomer Edward Singleton Holden. It is part of the Uzboi-Landon-Morava (ULM) system.
The Memnonia quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Memnonia quadrangle is also referred to as MC-16.
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 atwith 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.
Eberswalde, formerly known as Holden NE, is a partially buried impact crater in Margaritifer Terra, Mars. Eberswalde crater lies just to the north of Holden, a large crater that may have been a lake. The 65.3-km-diameter crater, centered at 24°S, 33°W, is named after the German town of the same name, in accordance with the International Astronomical Union's rules for planetary nomenclature. It was one of the final four proposed landing sites for the Mars rover Mars Science Laboratory mission. This extraterrestrial geological feature lies situated within the Margaritifer Sinus quadrangle (MC-19) region of Mars. Although not chosen, it was considered a potential landing site for the Mars 2020 rover, and in the second Mars 2020 Landing Site Workshop it survived the cut and was among the top eight sites still in the running.
Terby is a crater on the northern edge of Hellas Planitia, Mars. It is in the Iapygia quadrangle. The 174 km diameter crater is centered at 28°S, 73°E with an elevation of −5 km. It is named after François J. Terby. It is the site of an ancient lakebed and has clay deposits. Using data from Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter missions researchers believe Terby's layers were formed from sediments settling under water. Crater counts show this happened during the Noachian period. It used to be thought that Terby Crater contained a large delta. However, newer observations have led researchers to think of the layered sequence as part of a group of layers that may have extended all the across Hellas. There is no valley large enough at the northern rim of Terby to have carried the large amount of sediments necessary to produce the layers. Other details in the layers argue against Terby containing a delta. Fan deposits are some of the thickest on Mars. Hydrated minerals, including Fe/Mg phyllosilicates, have been detected in several layers.
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.
The Arabia quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Arabia quadrangle is also referred to as MC-12.
The Lunae Palus quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The quadrangle is also referred to as MC-10. Lunae Planum and parts of Xanthe Terra and Chryse Planitia are found in the Lunae Palus quadrangle. The Lunae Palus quadrangle contains many ancient river valleys.
The Oxia Palus quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Oxia Palus quadrangle is also referred to as MC-11.
The Sinus Sabaeus quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. It is also referred to as MC-20 . The Sinus Sabaeus quadrangle covers the area from 315° to 360° west longitude and 0° to 30° degrees south latitude on Mars. It contains Schiaparelli, a large, easily visible crater that sits close to the equator. The Sinus Sabaeus quadrangle contains parts of Noachis Terra and Terra Sabaea.
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.
Vernal is a crater on Mars, located at 6° north latitude and 355.5° east longitude in the Oxia Palus quadrangle. It is measures approximately 55.5 kilometers in diameter and was named after Vernal, Utah, United States. Structures resembling springs on Earth were found in Vernal crater.
Wislicenus is an impact crater on Mars, located in the Sinus Sabaeus quadrangle at 18.4° south latitude and 348.6° west longitude. It measures approximately 140 kilometers in diameter and was named after German astronomer Walter Wislicenus (1859–1905). The name was adopted by the IAU in 1973.
Spallanzani is a crater on Mars, located in the Hellas quadrangle at 58.0° south latitude and 86.4° east longitude. It measures approximately 72 kilometers in diameter and was named after Italian biologist Lazzaro Spallanzani (1729–1799). The name was adopted by IAU's Working Group for Planetary System Nomenclature in 1973.
Tikhonravov is a large, eroded crater in the Arabia quadrangle of Mars. It is 344 kilometres (214 mi) in diameter and was named after Mikhail Tikhonravov, a Russian rocket scientist. Tikhonravov is believed to have once held a giant lake that drained into the 4500 km long Naktong-Scamander-Mamers lake-chain system. An inflow and outflow channel has been identified. Many craters once contained lakes.
Flammarion is an impact crater in the Syrtis Major quadrangle on Mars at 25.2 ° N and 48.3 ° E. It is 173.0 km in diameter. Its name was approved in 1973, and refers to French astronomer Camille Flammarion. There may have been a lake in the crater in the past because a channel is visible on the rim in the picture below and layers are visible in one of the pictures.
Danielson Crater is an impact crater in the Oxia Palus quadrangle on Mars at 7.93° N and 7.11° W. and is 66.7 km in diameter, and is north of the Meridiani Planum, south of Arabia Terra and west of the planet's meridia. Its name was approved in 2009, and it was named after American engineer G. Edward Danielson.
Rutherford is an impact crater on Mars. It is located the Oxia Palus quadrangle inside Arabia Terra at 19.2° N and 10.7° W. and measures approximately 107 kilometers in diameter. The crater was named after British physicist Ernest Rutherford in 1973.
Crommelin Crater is an impact crater in the Oxia Palus quadrangle of Mars, located at 5.1°N latitude and 10.2°W longitude. It is 113.9 km in diameter. It was named after British astronomer Andrew Crommelin (1865–1939), and the name was approved in 1973 by the International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN).
In summer 1965, the first close-up images from Mars showed a cratered desert with no signs of water. However, over the decades, as more parts of the planet were imaged with better cameras on more sophisticated satellites, Mars showed evidence of past river valleys, lakes and present ice in glaciers and in the ground. It was discovered that the climate of Mars displays huge changes over geologic time because its axis is not stabilized by a large moon, as Earth's is. Also, some researchers maintain that surface liquid water could have existed for periods of time due to geothermal effects, chemical composition or asteroid impacts. This article describes some of the places that could have held large lakes.