Data Releases

Two principal physiographic province of Mars are represented in the Aeolis quadrangle: (1) Elysium Planitia in the north is part of a broad planet-encircling belt of relatively young lowland plains, and (2) cratered highlands in the south consist of rough primitive terrain that extends to polar deposits around the southern ice cap (Condit and Soderblom, 1978; Scott and Carr, 1978). These two terr

This 1:250,000- scale geologic map is one of a series prepared largely from photographs transmitted by Ranger IX (reproduced in a report by Jet Propulsion Lab., 1966). It depicts the geology of the crater Alphonsus (in which Ranger IX impacted) and environs. The primary objective of the mapping was to apply extant lunar mapping techniques used on relatively small scale telescopic photographs to th

The Amazonis quadrangle lies within the northern sparsely cratered hemisphere of Mars (Carr and others, 1973). The dominant structural and physiographic features of the quadrangle are low featureless plains (Amazonis Planitia) in the center third of the quadrangle, the western flanks of the large volcanic construct, Olympus Mons, and its associated aureole deposits (Lycus Sulci), which lies on the

The Arabia quadrangle is located in the northern hemisphere of Mars; it extends 30 degrees N. from the equator and 45 degrees E. from the prime meridian. It is within the area of unmantled terrain defined by Soberblom and others (1973) and the planet-encircling band of old cratered deposits shown on the preliminary geologic map of Mars (Carr and others, 1973). Crater density in the Arabia quadrang

The Arcadia quadrangle of Mars contains three distinct geologic provinces: (1) the 1000-km-diameter shield volcano of Alba Patera, which occupies the southwestern quadrant; (2) the complex Tempe province, which comprises a number of younger volcanic and sedimentary blanket deposits over an ancient, highly cratered crust forming a plateau in the southeastern quadrant; and (3) a plains province, con

The geology of the Argyre quadrangle of Mars is dominated by the conspicuous Argyre basin, defined by a rim of rugged mountain blocks that surrounds a nearly circular expanse of plains 800 km across. Of the large (greater than 500 km in diameter) basins identified on Mars, Argyre is the best preserved and probably the youngest. Basins appear to be traps for eolian debris and evidently are source a

The Aristoteles quadrangle, located on the northeastern periphery of the Imbrium basin on the near side of the Moon, consist of four physiographic provinces: a northern mountainous belt, chiefly of lineated crater rims and other lineated terra; a middle-northern belt covered by mare material of Mare Frigoris; and a southern belt composed of mountainous material of diverse characteristics. The crat

The Bach region encompasses the south polar part of Mercury poleward of lat 65 degrees S. About half of the region was beyond the terminator during the three Mariner 10 encounters and hence not visible. The entire mapped area was covered by near-vertical photography from the second encounter, and the eastern part, from long 15 degrees to about 110 degrees, was covered by oblique photography from t

The Beethoven quadrangle is located in the equatorial region of Mercury, in the center of the imaged area. Most pictures of the quadrangle were obtained at high sun angles as the Mariner 10 spacecraft receded from the planet. Images in the northeastern part of the quadrangle are very poor to unusable. Another difficulty in mapping is the poor match in topographic bases between Beethoven and adjace

Most of the photographs used for geologic mapping were acquired by the departing spacecraft during the first pass (Mercury I). The Mercury II encounter provided no usable images of the map area; two low-oblique photographs suitable for geologic mapping were acquired during the third flyby on March 17, 1975 (Davies and others, 1978, p. 31). No stereoscopic phtographic pairs are available for the Bo

The Magellan spacecraft orbited Venus from August 10, 1990, until it plunged into the venusian atmosphere on October 12, 1994. Magellan had the objectives of (1) improving knowledge of the geologic processes, surface properties, and geologic history of Venus by analysis of surface radar characteristics, topography, and morphology and (2) improving knowledge of the geophysics of Venus by analysis o

The Casius quadrangle (30 degrees N to 65 degrees N lat; 240 degrees W to 300 degrees W long) is one of the northern tier of Lambert conformal sheets of the Mars Atlas. It consists of four distinctive physiographic regions: 1) part of the northern cratered plain which forms an incomplete annulus around the north polar region, 2) smooth lowland plains of Utopia Planitia across the central and south