17-561: Lenya can refer to: Lenya , a town in Burma Lenya , a crater on Mars named after the Burmese town Lotte Lenya (1898–1981), Austrian-American singer and actress Jackie Lenya (1941), a British actress Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Lenya . If an internal link led you here, you may wish to change
34-558: A 16 cm (6.3 in) refractor , produced "the first really truthful representation of the planet" (in the estimation of E. M. Antoniadi ). Radar images by the Mars Reconnaissance Orbiter (MRO) spacecraft's SHARAD radar sounder suggest that features called lobate debris aprons in three craters in the eastern region of Hellas Planitia are actually glaciers of water ice lying buried beneath layers of dirt and rock. The buried ice in these craters as measured by SHARAD
51-421: A combination of glacial action and explosive boiling may be responsible for gully features in the crater. Some of the low elevation outflow channels extend into Hellas from the volcanic Hadriacus Mons complex to the northeast, two of which Mars Orbiter Camera images show contain gullies: Dao Vallis and Reull Vallis . These gullies are also low enough for liquid water to be transient around Martian noon, if
68-736: A full list, see List of craters in the Solar System . The total number of craters on Mars greater than 1 kilometre in diameter is approximately 385,000, with 21% of those (~85,000) being over 3 kilometers in diameter. The number of craters on Mars over 25 metres in diameter is suggested to be approximately 90 million. Some of the largest craters on Mars remain unnamed. Diameters differ depending on source data. The largest confirmed impact basins on Mars are Utopia (buried, estimated diameter 3,300 km) Hellas (2,300 km), Argyre ( 1,800 km) and Isidis (1,500 km). Hellas Planitia Hellas Planitia / ˈ h ɛ l ə s p l ə ˈ n ɪ ʃ i ə /
85-409: A specific town. Latitude and longitude are given as planetographic coordinates with west longitude. The catalog is divided into three partial lists: Names are grouped into tables for each letter of the alphabet, containing the crater's name (linked if article exists), coordinates, diameter in kilometers, year of official name adoption (approval), the eponym ("named after") and a direct reference to
102-524: Is a plain located within the huge, roughly circular impact basin Hellas located in the southern hemisphere of the planet Mars . Hellas is the third- or fourth-largest known impact crater in the Solar System . The basin floor is about 7,152 m (23,465 ft) deep, 3,000 m (9,800 ft) deeper than the Moon's South Pole-Aitken basin , and extends about 2,300 km (1,400 mi) east to west. It
119-405: Is about 250 m (820 ft) thick on the upper crater and about 300 m (980 ft) and 450 m (1,480 ft) on the middle and lower levels respectively. Scientists believe that snow and ice accumulated on higher topography, flowed downhill, and is now protected from sublimation by a layer of rock debris and dust. Furrows and ridges on the surface were caused by deforming ice. Also,
136-499: Is centered at 42°24′S 70°30′E / 42.4°S 70.5°E / -42.4; 70.5 . It features the lowest point on Mars , serves as a known source of global dust storms, and may have contained lakes and glaciers. Hellas Planitia spans the boundary between the Hellas quadrangle and the Noachis quadrangle . With a diameter of about 2,300 km (1,400 mi), it
153-517: Is mere coincidence, is unknown. Due to its size and its light coloring, which contrasts with the rest of the planet, Hellas Planitia was one of the first Martian features discovered from Earth by telescope . Before Giovanni Schiaparelli gave it the name Hellas (which in Greek means Greece ), it was known as Lockyer Land , having been named by Richard Anthony Proctor in 1867 in honor of Sir Joseph Norman Lockyer , an English astronomer who, using
170-644: Is the largest unambiguous well-exposed impact structure on the planet; the obscured Utopia Planitia is slightly larger (the Borealis Basin , if it proves to be an impact crater, is considerably larger). Hellas Planitia is thought to have been formed during the Late Heavy Bombardment period of the Solar System , approximately 4.1 to 3.8 billion years ago, when a protoplanet or large asteroid, suggested to be around 370 kilometres (230 mi) in diameter, hit
187-545: The Gazetteer of Planetary Nomenclature . As of 2017, Martian craters account for 21% of all 5,211 named craters in the Solar System . Apart from the Moon , no other body has as many named craters as Mars. Other, non-planetary bodies with numerous named craters include Callisto ( 141 ), Ganymede ( 131 ), Rhea (128), Vesta (90), Ceres (90), Dione (73), Iapetus (58), Enceladus (53), Tethys (50) and Europa ( 41 ). For
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#1732851200325204-604: The hundreds of thousands, but only about one thousand of them have names. Names are assigned by the International Astronomical Union after petitioning by relevant scientists, and in general, only craters that have a significant research interest are given names. Martian craters are named after famous scientists and science fiction authors, or if less than 60 km (37 mi) in diameter, after towns on Earth . Craters cannot be named for living people, and names for small craters are rarely intended to commemorate
221-482: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Lenya&oldid=1190533835 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages List of craters on Mars#L This is a list of craters on Mars . Impact craters on Mars larger than 1 km (0.62 mi) exist by
238-583: The shapes of many features in Hellas Planitia and other parts of Mars are strongly suggestive of glaciers , as the surface looks as if movement has taken place. These relatively flat-lying "cells" appear to have concentric layers or bands, similar to a honeycomb. This honeycomb terrain was first discovered in the northwestern part of Hellas. The geologic process responsible for creating these features remains unresolved. Some calculations indicate that this formation may have been caused by ice moving up through
255-441: The surface. The altitude difference between the rim and the bottom is over 9,000 m (30,000 ft). Despite being deeper than the Moon's South Pole-Aitken basin , Hellas' rim peaks are significantly less prominent. This may be because large Martian impacts such as Hellas induced global hot rainfall and meltwater flows that degraded crater rims, including their own. The crater's depth of 7,152 m (23,465 ft) below
272-516: The temperature were to rise above 0 Celsius. 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
289-500: The topographic datum of Mars explains the atmospheric pressure at the bottom: 12.4 mbar (1240 Pa or 0.18 psi) during winter, when the air is coldest and reaches its highest density. This is 103% higher than the pressure at the topographical datum (610 Pa, or 6.1 mbar, or 0.09 psi) and above the triple point of water , suggesting that the liquid phase could be present under certain conditions of temperature, pressure, and dissolved salt content. It has been theorized that
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