Instruct: Given a question, retrieve relevant documents that can help answer the question.
Query: How large is the Elysium Planitia region of Mars?
A 2005 photo of a locale in Elysium Planitia at 5°N, 150°E by the Mars Express spacecraft shows what may be ash-covered water ice. The volume of ice is estimated to be 800km (500mi) by 900km (560mi) in size and 45m (148ft) deep, similar in size and depth to the North Sea.[3] The ice is thought to be the remains of water floods from the Cerberus Fossae fissures about 2 to 10 million years ago. The surface of the area is broken into 'plates' like broken ice floating on a lake (see below). Impact crater counts show that the plates are up to 1 million years older than the gap material, showing that the area solidified much too slowly for the material to be basaltic lava.[4]
InSight, launched from Earth May 5, 2018, the lander touched down on Mars November 26, 2018 on Elysium Planitia. 
Perhaps the youngest outflow channel on Mars is Athabasca Valles. It lies 620 miles southeast of the large volcano Elysium Mons. Athabasca was formed by water that burst out of Cerberus Fossae, a set of cracks or fissures in the ground. Cerberus Fossae most likely was formed from the stress on the crust caused by the weight of both Elysium Mons and Tharsis volcanoes. Current evidence suggests that Cerberus floods probably erupted in several stages. Near the start of these channels (Cerberus Fossae), the system is called Athabasca Valles, to the south and east it is called Marte Vallis. Flow rates in Marte Vallis have been estimated at around 100 times that of the Mississippi River. Eventually, the system just seems to fade out in the plains of Amazonis Planitia.
On November 22, 2016, NASA reported finding a large amount of underground ice in the Utopia Planitia region of Mars. The volume of water detected has been estimated to be equivalent to the volume of water in Lake Superior. ()
Phlegra Montes is a system of eroded Hesperian-Amazonian-aged massifs and knobby terrain in the mid-latitudes of the northern lowlands of Mars, extending northwards from the Elysium Rise towards Vastitas Borealis for nearly . The mountain ranges separate the large plains provinces of Utopia Planitia (west) and Amazonis Planitia (east), and were named in the 1970s after a classical albedo feature. The massif terrains are flanked by numerous parallel wrinkle ridges across Phlegra Dorsa.
David H. Scott and Mary G. Chapman of the United States Geological Survey published an examination of Elysium Planitia in 1991, including an updated geologic map of the region, proposing that Elysium Planitia was a basin that held a paleolake, interpreting the features in what they dubbed the "Elysium Basin" as sedimentary in origin.
The name Elysium refers to a place of reward (Heaven), according to Homer in the Odyssey.
The Elysium quadrangle covers the area 180° to 225° west longitude and 0° to 30° north latitude on Mars. Elysium Planitia is in the Elysium quadrangle. The Elysium quadrangle includes a part of Lucus Planum. A small part of the Medusae Fossae Formation lies in this quadrangle. The largest craters in this quadrangle are Eddie, Lockyer, and Tombaugh. Elysium contains major volcanoes named Elysium Mons and Albor Tholus and river valleys—one of which, Athabasca Valles may be one of the youngest on Mars. On the east side is an elongated depression called Orcus Patera. A large lake may once have existed in the south near Lethe Valles and Athabasca Valles.
Chryse Planitia is a roughly circular volcanic plain west of the Tharsis bulge and its associated volcanic systems. This region contains the most prominent and numerous outflow channels on Mars. The channels flow east or north into the plain.In this region it is particularly difficult to distinguish outflow channels from lava channels but the following features have been suggested as at least overprinted by outflow channel floods:Several channels flow either onto the plains of Amazonis and Elysium from the southern highlands, or originate at graben within the plains. This region contains some of the youngest channels. Some of these channels have rare tributaries, and they do not start at a chaos region. It has been suggested the formation mechanisms for these channels may be more variable than for those around Chryse Planitia, perhaps in some cases involving lake breaches at the surface.Several outflow channels rise in the region west of the Elysium volcanic province and flow northwestward to the Utopia Planitia. As common in the Amazonis and Elysium Planitiae regions, these channels tend to originate in graben. Some of these channels may be influenced by lahars, as indicated by their surface textures and ridged, lobate deposits at their margins and termini. The valleys of Hephaestus Fossae and Hebrus Valles are of extremely unusual form, and although sometimes claimed as outflow channels, are of enigmatic origin.Three valleys flow from east of its rim down onto the floor of the Hellas basin.It has been argued that Uzboi, Ladon, Margaritifer and Ares Valles, although now separated by large craters, once comprised a single outflow channel flowing north into Chryse Planitia. The source of this outflow has been suggested as overflow from the Argyre crater, formerly filled to the brim as a lake by channels (Surius, Dzigai, and Palacopus Valles) draining down from the south pole. If real, the full length of this drainage system would be over 8000 km, the longest known drainage path in the solar system. Under this suggestion, the extant form of the outflow channel Ares Vallis would thus be a remolding of a pre-existing structure.
Athabasca Valles is a late Amazonian-period outflow channel in the central Elysium Planitia region of Mars, located to the south of the Elysium Rise. It is part of a network of outflow channels in this region that are understood to emanate from large fissures in the Martian surface rather than the chaos terrains that source the circum-Chryse outflow channels. Athabasca Valles in particular emanates from one of the Cerberus Fossae fissures and flows downstream to the southwest, constrained to the south by a wrinkle ridge for over 100 km, before debouching into the Cerberus Palus volcanic plain. Athabasca Valles is widely understood to be the youngest outflow channel on the planet.
Athabasca Valles is located within the broader Elysium Planitia region and cross-cuts a vast swath of plains land interpreted to be composed largely of flood basalts. The outflow channels of central Elysium Planitia are distinguished from those of circum-Chryse region (Kasei Valles, Ares Vallis, etc.) because they appear to emanate from volcanic fissures rather than chaos terrain. Athabasca Valles is the westernmost of the outflow channels in Elysium Planitia and the only one of the channels in this region that flows westwards. The other major outflow channels in this region are (from west to east) Grjotá Valles, Rahway Valles, and Marte Vallis. Historically, some researchers have associated the outpouring of fluid from Athabasca Valles with the downstream formations of Marte Vallis and Grjotá Valles, but this perspective fell out of favor as higher-resolution MOC data became available, allowing updated crater counts (the age dates of each valley floor are asynchronous) and geomorphic interpretations (high-permeability fresh lava rock would have caused large-scale infiltration of errant floodwaters long before reaching the other valleys' heads).
Avernus Colles is a region of fractured terrain on Mars on the southeast margin of Elysium Planitia, at 1.6°S, 171°E. It is fairly large, being 244 km (152 mi) in diameter. Avernus Colles can be found in the Elysium quadrangle. It was named in 1985 after a lake in Campania, Italy, which is believed by some to be an entrance to the underworld.
Elysium Planitia, located in the Elysium and Aeolis quadrangles, is a broad plain that straddles the equator of Mars, centered at .[1] It lies to the south of the volcanic province of Elysium, the second largest volcanic region on the planet, after Tharsis. Elysium contains the major volcanoes Elysium Mons, Albor Tholus and Hecates Tholus. Another more ancient shield volcano, Apollinaris Mons, is situated just to the south of eastern Elysium Planitia.
Albor Tholus is an extinct volcano in the volcanic province Elysium on Mars. It lies south of the neighbouring volcanoes Elysium Mons and Hecates Tholus. Albor Tholus is 4.5 kilometres high and has a diameter of 160 km at its base. Its large caldera, having a diameter of 30 km and a depth of 3 km, is deep compared to calderas on the Earth. The elevation of the lowest level of the caldera is the same as the base of the volcano; however, the original lower slopes of Albor Tholus may have been covered by lava flows from its larger neighbor, Elysium Mons. Evaluations by the Mars probe Mars Express found that the volcanoes of the Elysium region were active over long periods.
Some authors have proposed that a combination of mechanisms can satisfactorily explain the origin of the Athabasca Valles system - namely, the large-scale emplacement of low-viscosity lava flows on top of pre-existing glaciers. Apart from ice interactions, this large-scale low-viscosity volcanic efflux is thought to have formed up to a third of the modern Martian surface and has been analogized to Earth's large igneous provinces (LIPs). Individual periods of volcanic activity constituting the modern Elysium Planitia region are thought to have lasted up to 1 Myr, with the rock in the vicinity of Athabasca Valles being potentially deposited on a timescale of weeks or months. Given the obliquity of Mars during this part of the Amazonian, it has been hypothesized that glaciers were likely actively accumulating in this region of Elysium Planitia at the same time as this period of volcanism.
The largest craters in Elysium Planitia are Eddie, Lockyer, and Tombaugh. The planitia also has river valleys—one of which, Athabasca Valles may be one of the youngest on Mars. On the north east side is an elongated depression called Orcus Patera, and this and some of the eastern plains were imaged in the 1965 Mariner 4 flyby.[2]
Fossa (geology) Geography of Mars Geology of Mars List of plains on Mars List of quadrangles on Mars
– zoomable map centered on Elysium Planitia, with three main volcanoes of Elysium visible by Seán Doran of overflight of an with a (1.1° S, 159.7° E)
Utopia Planitia (Greek and Latin: "Nowhere Land Plain"—loosely, the plain of paradise) is a large plain within Utopia, the largest recognized impact basin on Mars and in the Solar System with an estimated diameter of 3,300 km, and is the Martian region where the Viking 2 lander touched down and began exploring on September 3, 1976. It is located at the antipode of Argyre Planitia, centered at . It is in the Casius quadrangle, Amenthes quadrangle, and the Cebrenia quadrangle of Mars.
Amazonis Planitia is one of the smoothest plains on Mars. It is located between the Tharsis and Elysium volcanic provinces, to the west of Olympus Mons, in the Amazonis and Memnonia quadrangles, centered at . The plain's topography exhibits extremely smooth features at several different lengths of scale. A large part of the Medusae Fossae Formation lies in Amazonis Planitia.
At a 1998 NASA workshop at Ames Research Center near San Jose, California, James W. Rice and David H. Scott (of Ames and of the US Geological Survey, respectively) narrowed down 11 candidate landing sites for the now-canceled NASA Mars Surveyor mission. Elysium Planitia was one of the chosen sites, with Athabasca Valles' putative hydrothermal origin a major motivation for proposing the Elysium landing site.
Elysium, located in the Elysium and Cebrenia quadrangles, is the second largest volcanic region on Mars, after Tharsis. The region includes the volcanoes (from north to south) Hecates Tholus, Elysium Mons and Albor Tholus. The province is centered roughly on Elysium Mons at . Elysium Planitia is a broad plain to the south of Elysium, centered at . Another large volcano, Apollinaris Mons, lies south of Elysium Planitia and is not part of the province. Besides having large volcanoes, Elysium has several areas with long trenches, called fossa or fossae (plural) on Mars. They include the Cerberus Fossae, Elysium Fossae, Galaxias Fossae, Hephaestus Fossae, Hyblaeus Fossae, Stygis Fossae and Zephyrus Fossae.
Hellas Planitia is antipodal to Alba Patera. It and the somewhat smaller Isidis Planitia together are roughly antipodal to the Tharsis Bulge, with its enormous shield volcanoes, while Argyre Planitia is roughly antipodal to Elysium, the other major uplifted region of shield volcanoes on Mars. Whether the shield volcanoes were caused by antipodal impacts like that which produced Hellas, or if it is mere coincidence, is unknown.
Apollinaris Mons is an ancient shield volcano in the southern hemisphere of Mars. It is situated near the equator, south of Elysium Planitia and north of Gusev crater. Elysium Planitia separates it from the volcanic province of Elysium to its northwest. The volcano's caldera is named Apollinaris Patera; this name formerly applied to the whole edifice.
The mission launched on 5 May 2018 and landed on the surface of Mars at Elysium Planitia on 26 November 2018.
NASA's InSight mission landed on Elysium Planitia on November 26, 2018.[5] It took off from Earth on the 5th May 2018. The probe will study the internal structure of Mars and by so doing improve understanding of the planet's evolution. InSight Mars lander was able to take color pictures from the surface Elysium Planitia and sent them by radio signal back to Earth. During the descent sequence two additional items were jettisoned, the backshell with parachute, and heat shield, and they impacted in the vicinity of the lander.