513:(Guest and Greeley, 1983), only the uppermost parts of walls and rims protrude above smooth plains material. Ghost craters of this type display rounded rim crests that are densely cratered with secondaries, a feature typical of the rough surface of intercrater plains material. These craters are floored by smooth plains material and are therefore older than it; a similar relation occurs on the Moon, where the crater Archimedes is seen to be older than the mare material it contains. Another type of ghost crater, common in Borealis Planitia, is recognized only by an irregular or thin outline of a rim crest under a thin mantle of smooth plains material; the buried rim crest is shown on the map. The polygonal ghost crater centered at lat 82.5° N., long 100° W., northwest of Depréz, is a transitional form between these two types. Polar darkening is generally lacking on Mercury (Hapke, 1977), but darkening in restricted areas may be due to vapor-phase deposition accompanying micrometeorite impacts (Hapke, 1977). In the Borealis region, surface darkening affects some crater floors, and low-albedo areas are mapped in both intermediate plains and smooth plains materials. The low-albedo plains are marginal to the borders of Borealis and Suisei Planitiae, which suggests that darkening may be due to internal volatile materials escaping along the fractured margins of unrecognized buried or very degraded basins.
559:
hand, some ridges on the surface of the smooth plains material in
Borealis Planitia may be of structural (internal) origin; this type of ridge elsewhere on Mercury has been ascribed to compression and a slight shortening of the crust (Melosh, 1977; Melosh and Dzurisin, 1978). On the other hand, the wrinklelike sinuous ridge along the northeast border of the Goethe Basin, together with the outward-facing concentric scarps along its periphery, may represent the fronts of lava flows that are associated with the development of a structural moat between the basin fill and the wall. The latter interpretation supports the view that impact craters and basins on Mercury, as on the Moon (Schultz, 1977) and Mars, "have played a dominant role in controlling the surface expression of igneous activity" (Schultz and Glicken, 1979, p. 8033). Slow, long-lasting isostatic adjustment of the basin floor may have continued well after the emplacement of the basin fill, a structural situation similar to that of crater Posidonius on the Moon (Schaber and others, 1977, Schultz, 1977).
563:
to 160 km, that are buried under the smooth plains material of
Borealis Planitia, which material is coextensive with the fill covering the floor of the Goethe Basin. In addition, ejecta from the crater DeprĂ©z extend more than 40 km eastward beyond a circular scarp that may represent the rim crest of a buried crater 170 km in diameter (FDS 156, 160) or, more likely, the front of lava flows. The size and density of these ghost craters suggest that, prior to emplacement of smooth plains material, the original heavily cratered surface of Borealis Planitiaâwhich may have been the cratered floor of a very large multiring impact basinâand the cratered floor of the Goethe Basin were similar in composition and age to the intercrater plains material of the highlands to the west. Many scarps in Borealis Planitia are subconcentric to the rim of the Goethe Basin and have steeper slopes that face away from it, suggesting that they represent the fronts of lava flows that resurfaced extensive areas of heavily cratered terrain (intercrater or older plains material).
580:
expansion and differentiation of the crust. The size and density of ghost craters that are detectable under the smooth plains material in the interior of the Goethe Basin are indicative of an original basin floor much modified by cratering and emplacement of intercrater materials prior to the emplacement of intermediate and smooth plains materials. This interpretation implies, therefore, that the formation of the Goethe Basin predated or occurred soon after the emplacement of intercrater plains material had begun. The relative similarity in albedo of the
Mercurian plains, whether formed of intercrater, intermediate, or smooth plains materials, also suggests a similarity in chemical composition and possibly in mode of emplacement of plains materials. The high crater density of intercrater and intermediate plains materials makes it likely, however, that the original rock types of these two units (whether
205:
high latitudes. Its pronounced orbital eccentricity (0.2563) causes the apparent solar intensity at
Mercury to vary by more than a factor of 2 throughout a Mercurian year, corresponding to about a 20 percent change in equilibrium temperature. Further, conservation of orbital angular momentum and spin-orbit coupling cause considerable variation in the length of daylight. Dawns and sunsets are prolonged by the long transit time of the Mercurian horizon across the solar disk, so that daylight is lengthened and nighttime reduced by several terrestrial days at sunset and vice versa at sunrise (Robert Wildey, U.S. Geological Survey, oral commun., 1982). Despite these considerations and despite the daily range in surface temperatures of several hundred kelvins, the subsurface temperature in the polar regions always remains well below freezing (Murray, 1975).
32:
380:(Schaber and McCauley, 1980). On its west side, Goethe is bounded by at least three subparallel ridges or tilted blocks, which are separated by narrow troughs partly filled with smooth plains material. Hilly and hummocky remnants resembling basin deposits and ejecta protrude above the gently sloping basin wall. They extend southwest and north of the basin beyond a much subdued, low, barely perceptible rim crest for a distance of one-half to one-third of the basin radius. Goethe is older than the smooth plains material by which its wall, rim crest, and most of its ejecta were partly buried. The Goethe impact basin may be older than some intercrater plains material and large craters nearby. It is also much older than the Caloris Basin. (McCauley and others, 1981).
551:). This set of northeast-trending scarps and troughs, and another set of north-trending scarps and troughs within and north of crater Van Dijck, probably follow zones of structural weakness in the mercurian crust. Ancient fractures that were reactivated by later impacts may have first provided the conduits for crater fill (smooth plains material) and later been propagated upward through the fill. That these ridges, scarps, and troughs are parts of a global grid of fractures cannot be stated conclusively because of their proximity to the terminator and the lack of photographic coverage beyond the 190° meridian. Some scarps probably were formed by normal faulting of the smooth plains material that covers some crater floors, as in the
555:(Scott and others, 1980). We cannot, however, determine whether most lineaments are internal or are parts of a faulted and lineated facies associated with a nearby but unphotographed impact basin. Melosh (1977) predicted that normal east-trending faults would form in high Mercurian latitudes as a result of slight crustal shortening. His predicted faults may be represented by a generally east-northeast-trending scarp and a lineament that cut across intermediate plains material and the crater Jókai between the 125° and 155° meridians. The north pole is too close to the terminator to detect the presence or absence of a "polygonal arrangement without preferred orientation," as predicted by Melosh and Dzurisin (1978, p. 233).
467:. The enormous volume of smooth plains material that must underlie Borealis Planitia in order to bury pre-existing topography, as well as the presence of the material in basin and crater floors, suggest that the smooth plains material was emplaced in a fluidized state as volcanic lava flows (Murray and others, 1974). Even though flow fronts cannot be unambiguously mapped on Borealis Planitia, further evidence of the unit's volcanic origin is supplied by its overlap onto intercrater plains material, best observed along the west edge of Borealis Planitia (FDS 85, 152, 153, 156, and 160). The various types of plains material recognized on Mercury exhibit little tonal contrast. The
283:. The unit was described originally by Trask and Guest, who considered it to be the most widespread unit on Mercury; Strom reported that this material covers one-third of the surface viewed by Mariner 10. The principal morphologic characteristic of the intercrater plains material is the high density of superposed craters 5 to 10 km in diameter, which are commonly shallow and elongate; probably they are secondary craters derived from nearby large primary craters that are superposed on the unit. As one group, the large craters and associated intercrater plains form some of the heavily cratered terrain defined by Trask and Guest.
396:, 110 km (68 mi) in diameter, is large enough to be a central-peak basin (Wood and Head, 1976), even though the peak ring probably has been concealed under smooth plains material. The rims of both Botticelli and Turgenev are covered with densely packed craters, most of which resemble the secondary craters that typically occur on intercrater plains material. Therefore, Botticelli and Turgenev are at least as old as intercrater plains material and may be equivalent in age to the Goethe impact basin. A similar argument can be advanced for the age of the
501:
Depréz. Slight differences between mercurian and lunar crater morphologies are unrelated to differences in the
Mercurian and lunar gravitational fields (Cintala and others, 1977; Malin and Dzurisin, 1977, 1978;). Instead, the morphologic components of crater interiors and the abundance of central peaks and terraces on both bodies seem to be related to the physical properties of the target material (Cintala and others, 1977; Smith and Hartnell, 1978). The clusters of closely packed and overlapping large craters west of crater
266:
p. 80â81) and for Mars (Boyce and others, 1976). In the
Borealis region, where intercrater and intermediate plains materials were imaged at an increasingly low sun angle close to the terminator, the number of observable small craters increase with decreasing distance from the terminator and concomitantly decreasing sun angle. This discrepancy in the apparent abundance of craters occurs only for craters that have small diameters and can be obviated by counting only craters larger than 3 km (1.9 mi) in diameter.
360:. Intermediate plains material was first recognized and mapped in the Tolstoj quadrangle (Schaber and McCauley, 1980), where it primarily occurs on the floors of craters. It was identified there by a lower crater density than that of intercrater plains material and by "a lower incidence of small bright-halo craters than are found on the smooth plains material" (Schaber and McCauley, 1980). Both characteristics are also typical of intermediate plains material in the Borealis region.
41:
138:
20:
3422:
3434:
530:
more detailed description is given by Strom and others. Dzurisin (1978) classified these scarps, differentiating between intercrater and intracrater scarps (a scheme adopted in mapping the
Borealis region) in an attempt to understand the tectonic and volcanic history of Mercury. Melosh (1977) and Melosh and Dzurisin (1978) proposed a planetary grid composed of conjugate northeastand northwest-trending shear fractures formed by the stresses of
262:, are included in these counts. The plains materials that lie outside Borealis Planitia are distributed in irregular belts, which are subparallel to the terminator and to one another. Eastward from long 190° W., the following belt pattern is observed: intercrater plains material, intermediate plains material, and again intercrater plains material. All three belts extend southward into the Shakespeare quadrangle (Guest and Greeley, 1983).
348:. However, planetwide, the morphologic evidence for an impact origin rather than a volcanic one is not compelling. Whether or not either hypothesis is eventually substantiated, the emplacement of intercrater plains material likely began during an early stage of intense accretionary bombardment (Guest and OâDonnell, 1977) and lasted until the time of formation of intermediate plains material.
489:
All basins between 100 km (62 mi) and 200 km (120 mi) in diameter (including those that have central peaks and peak rings) are mapped as craters. Criteria used to determine impact structures are morphologic crater components such as rays, secondary rays, hummocky rims, various facies of crater ejecta, crater geometry and structure, or a combination of these.
352:
diameter on
Mercury also are relatively scarce compared to similar craters in the lunar uplands northwest of crater Tsiolkovskiy. The reduced density of large craters and basins on Mercury relative to the Moon could be either a function of different crater-population rates on these bodies or an effect of different crustal histories (Schaber and others, 1977).
238:. The curve for the southeastern part of Oceanus Procellarum was obtained in an area centered near lat 2°00' N. and long 31°00'W., south of the crater Kunowsky. Ocean Procellarum has long been considered close to the "average lunar mare" (Hartmann, 1966, 1967); its crater density is intermediate between those of the heavily cratered
493:
across
Borealis Planitia as far as the Goethe Basin, may radiate from small unnamed and unmapped rayed craters near the south edge of the map area. The relative scarcity of small bright-halo craters on intermediate plains material, perhaps due to unique physical properties of this material, was first noted in the
325:
crustal cratering, but not necessarily at the same absolute geologic time. Differences in crater density as well as embayment relations in the
Borealis region show that the intercrater plains material and the smoother intermediate plains material are younger than many craters in the area northeast of crater
603:
The mercurian surface reached its present configuration several billion years ago (Solomon, 1978). It has been only slightly altered since by impact craters, which are ubiquitously superposed on all other deposits. Generalized summaries of the history of Mercury have been given by Guest and OâDonnell
562:
In Borealis Planitia, however, most of the ridges are of external origin. They appear either to outline the rim crests of subjacent ghost craters that are lightly mantled by smooth plains material or to be lava flow fronts. The map shows the rim crests of 20 ghost craters, ranging in diameter from 40
324:
craters (Wilhelms and El- Baz, 1977). The similarity in crater density of intercrater plains material on Mercury and of pre-Nectarian terrain on the Moon is geologically significant, inasmuch as it shows that the oldest recognizable surfaces on both Mercury and the Moon went through similar stages of
167:
was a few degrees away from the 0°-180° meridian at the time of the first encounter, photographs of the region were acquired under a wide range of lighting conditions. These conditions and the large obliquity of the photographs hampered geologic interpretation of surface materials in the map area, as
571:
Five periods were postulated by Murray and others (1975) to constitute the history of Mercuryâs surface: (1) accretion and differentiation; (2) terminal bombardment; (3) formation of the Caloris Basin; (4) flooding of that basin and other areas; and (5) light cratering on the smooth plains. Only the
529:
resulting from a period of crustal compression..." These scarps are unique structural landforms that were noted soon after the acquisition of Mariner 10 photographs. Murray and others (1974) described them as having a sinuous outline, a slightly lobate front, and a length of more than 500 km. A
505:
and east of crater Mansart, together with nearby isolated craters and surrounding material, were mapped by Trask and Guest as heavily cratered terrain. According to them, many of the small craters superposed on the intercrater areas may be secondaries from the large craters. They also noted that the
457:
Smooth plains material (unit ps) forms the vast expanses of Borealis and Suisei Planitiae, as well as most basin and crater floors. It is the most extensive stratigraphic unit in the Borealis region, covering 30 percent of the mapped area. The surface of the smooth plains material is rather sparsely
383:
Several additional impact structures within and to the south of the Borealis region display sufficient structural detail to be called basins, even though their diameters are less than the arbitrarily chosen 200 km lower limit adopted by Murray and others (1974) for mercurian basins. The largest
371:
is a large circular depression that measures approximately 400 km (250 mi) in diameter from rim crest to rim crest. Goethe is bounded on its north and east sides by a gently sloping wall and discontinuous, low, hummocky rim material that may consist of ejecta deposits. These materials are
91:
images(Murray and others, 1974; Boyce and Grolier, 1977; Strom, 1977). The west half of the mapped area (between long 100° and 190° W.) is dominated by older craters and by intercrater plains material that lies between and within them. Younger crater materials, intermediate plains material, and
558:
Arcuate and radial lineaments that might result from tectonic adjustments of the Mercurian crust, following excavation of very large multiring impact basins such as the one postulated under Borealis Planitia (Boyce and Grolier, 1977), were not unambiguously identified in the Borealis region. On one
492:
No rayed craters â„ 30 km (19 mi) in diameter were observed in the mapped area, but many moderately bright and diffuse rays extend across smooth plains material or occur as halos around very small craters in Borealis Planitia. A train of northeast-trending discontinuous rays, which extends
488:
In the Borealis region, craters are mapped according to the fivefold classification proposed by McCauley and others (1981), which determines Mercurian crater ages on the basis of crater diameter and morphologic degradation. Craters less than about 30 km (19 mi) in diameter are not mapped.
213:
Within the Borealis region, three widespread plains units are recognized largely by their obvious differences in crater density, which is closely related to relative age (Soderblom and Boyce, 1972). From most heavily cratered (oldest) to least cratered (youngest), these units are intercrater plains
538:
The northwest-trending component of the postulated global grid of fractures is markedly absent in the Borealis region. Northeast-trending scarps and troughs are conspicuous, however, across intercrater plains material and in crater fill (smooth plains material) between the 155° and 185° meridians,
265:
Distinguishing one type of plains material from another by variations in roughness and crater density is highly dependent on the resolution and lighting conditions of individual Mariner frames (Schaber and McCauley, 1980). This constraint is well documented for the Moon (Masursky and others, 1978,
623:
Prepared for the National Aeronautics and Space Administration by the U.S. Department of the Interior, U.S. Geological Survey (Published in hardcopy as USGS Miscellaneous Investigations Series Map Iâ1660, as part of the Atlas of Mercury, 1:5,000,000 Geologic Series. Hardcopy is available for sale
500:
The reduced ballistic range on Mercury compared to the Moon is caused by Mercury's stronger gravitational field (McCauley and others, 1981). This phenomenon, which results in a reduced dispersion of ejecta and secondary craters, is best observed within the Borealis region around craters Verdi and
471:
of smooth plains material is higher than that of lunar mare material (Hapke and others, 1975). The similarity in albedo between mercurian smooth plains material and lunar light plains material led Wilhelms to extend the analogy to composition: he suggested that both units consist of impact ejecta
204:
create a variation of mean temperature not only with latitude, as on the Earth, but also with longitude. However, because of Mercury's relatively slow rotational period, diurnal variations in temperature probably greatly exceed mean-temperature variations along latitude and longitude, even in the
534:
early in mercurian history. They thought that these fractures were later modified, and predicted that east-trending normal faults caused by tensional stresses would be found in the polar regions. In a later report, Pechmann and Melosh (1979, p. 243) stated that "the NE and NW trends become
579:
of impact and volcanic deposits, was emplaced over a long period that extended past the creation of the Goethe Basin and many smaller basins and craters. The scarps and troughs that trend across intercrater plains material may indicate an early compressional episode that followed even earlier
388:, a crater 140 km (87 mi) in diameter centered at lat 64°N., long 110°W. Only the northernmost parts of the craterâs rim and interior lie within the mapped area, but the ghost remnant of an inner ring now flooded by smooth plains material is recognized (FDS 148) farther south in the
351:
This general conclusion seems to be supported in the Borealis region by the relative scarcity of craters between 30 km and 60 km in diameter. This scarcity may indicate resurfacing by crater overlap and blanketing by crater ejecta or resurfacing by lava flows. Craters â„60 km in
159:
flyby acquired the most useful photographs of the region. 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
462:
are common. Both the floor of the Goethe Basin and the younger craters (now observed as buried craters) superposed on it are mantled by smooth plains material; the unit also fills ghost and flooded craters that are common on both Borealis and Suisei Planitiae and resemble the lunar crater
435:
on the Moon. Two of the most striking of these knobs are possibly 2 km (1.2 mi) long and 0.2 km (0.12 mi) across; they rise above smooth plains material that fills a much degraded, unmapped, irregular crater at 69° N., 157° W. (FDS 088). These knobs are about
355:
Intermediate plains material has a roughness and crater density transitional between intercrater plains material and smooth plains material. In the Borealis region, the unit occurs in a rather extensive belt that extends from the Shakespeare quadrangle into Borealis north and northeast of
599:
Goethe Basin is considerably older than the Caloris Basin. Emplacement of the smooth plains material of Borealis Planitia during several or many episodes resulted in resurfacing and smoothing of the original material of the Goethe Basin and its surroundings for hundreds of kilometers.
214:
material, intermediate plains material, and smooth plains material. Visual identification is confirmed and refined by actual crater counts. If one uses the lunar surface as a frame of reference, the crater density of Mercurian plains in the Borealis region is bracketed by that of the
35:
Mercuryâs north polar region made from the Arecibo Observatory is shown in yellow on a mosaic of MESSENGER orbital images. Radar-bright features all collocate with areas mapped as in shadow by MESSENGER, consistent with the proposal that radar-bright materials contain water
1061:
Boyce, J. M., and Grolier, M. J., 1977, The geology of the Goethe (H-l) quadrangle of Mercury, in Arvidson, Raymond, and Wahmann, Russell, eds., Reports of planetary geology program, 1976â1977: National Aeronautics and Space Administration Technical Memorandum X-3511,
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on the Moon (Wilhelms and McCauley, 1971; Scott, 1972). The pits in the lunar pre-Imbrian pitted plains are similar to the small secondaries that pepper the surface of Mercurian intercrater plains material. On the Moon, pre-Imbrian pitted plains material embays the
274:
The intercrater plains material is the oldest recognizable map unit in the Borealis region. It lies between large craters from about long 155° to long 190° W., and it also occurs between clusters of closely packed and overlapping large craters west of crater
1065:
Cintala, M. J., Wood, C. A., and Head, J. W., 1977, The effects of target characteristics on fresh crater morphology: Preliminary results for the moon and Mercury: Lunar Science Conference, 8th, Houston, 1977, Proceedings, p. 3409â3425, 4 figs., 3
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Scott, D. H., Underwood, J. R., Jr., and De Hon, R. A., 1980, Normal faults on Mercury: Example in the Kuiper quadrangle, in Reports of planetary programs, 1979â1980: National Aeronautics and Space Administration Technical Memorandum 81776,
1266:
Soderblom, L. A., and Boyce, J. M., 1972, Relative age of some near-side and far-side terra plains based on Apollo 16 metric photography: Apollo 16 Preliminary Report: National Aeronautics and Space Administration Special Publication 315,
249:
Material of Borealis Planitia was not included in the smooth plains count because images of the area were blurred by spacecraft motion, and so reliable crater counts could not be obtained. However, smooth plains south of lat 65° N. in the
440:
and may represent Caloris Basin ejecta. Alternatively, they may be associated with crater Verdi ejecta or with lineated and secondary-crater ejecta that flare southeastward from an unnamed crater north of and adjacent to the crater
1191:
Murray, B. C., Belton, J. J. S., Danielson, G. E., Davies, M. E., Gault, D. E., Hapke, Bruce, OâLeary, Brian, Strom, R. G., Suomi, Verner, and Trask, Newell, 1974, Mercuryâs surface: Preliminary deseription and interpretation from
286:
The relative age and nature of intercrater plains material are as uncertain in the Borealis region as they are elsewhere on Mercury. Strom noted the similarity in surficial morphologies between mercurian intercrater plains and
480:. Wilhelms even hypothesized that the source basin for material of the extensive plains of Borealis Planitia "could well be lurking in the darkness beyond the terminator." A fuller discussion of the problem is given by Strom.
103:, a depression about 1,000 km (620 mi) in diameter that has an irregular arcuate west boundary. This depression is located over the site(s) of one or several old impact structures (Boyce and Grolier, 1977).
304:(Stuart-Alexander and Wilhelms, 1975). However, the crater density of the intercrater plains material in the Borealis region matches that of an area on the far side of the Moon, in the region northwest of crater
1304:
Wood, J. A., Dickey, J. S., Marvin, U. B., and Powell, B. N., 1970, Lunar anorthosites and a geophysical model of the Moon: Apollo 11 Lunar Science Conference, Houston, 1970, Proceedings, v. 1, p. 965â
412:, which have prominent central peaks and ghostlike discontinuous inner rings, probably qualify as central-peak basins (Wood and Head, 1976). Both structures are considerably younger than the Caloris Basin.
1057:
Boyce, J. M., Dial, A. L., and Masursky, Harold, 1976, The optimal sun angle for obtaining photographs of martian surface features from orbit: U.S. Geological Survey Interagency Report: Astrogeology 78, 8
449:. These grooves are as much as several kilometers long and several hundred meters wide. The direction of elongation of many small secondary craters also suggests an origin related to the Caloris event.
423:(McCauley and others, 1981), can be unambiguously identified in the Borealis region. A few rounded hills or knobs, too small to be mapped, are present; they are morphologically similar to blocks of the
1085:
De Hon, R. A., Scott, D. H., and Underwood, J. R., Jr., 1981, Geologic map of the Kuiper quadrangle of Mercury; U.S. Geological Survey Miscellaneous Investigations Series Map I-1233, scale 1:5,000,000.
96:, 122 km (76 mi) in diameter, is the largest of the younger craters. Its extensive ejecta blanket and secondary crater field are superposed on plains materials and older craters.
1097:
Guest, J. E., and Greeley, Ronald, 1983, Geologic map of the Shakespeare quadrangle of Mercury: U.S. Geological Survey Miscellaneous Investigations Series Map I-1408, scale 1:5,000,000.
1233:
Schaber, G. G., and McCauley, J. F., 1980, Geologic map of the Tolstoj quadrangle of Mercury: U.S. Geological Survey Miscellaneous Investigations Series Map I-1199, scale 1:5,000,000.
445:. Another morphologic feature that may be related to the Caloris Basin event consists of grooves on intercrater plains material and on the southwest-facing walls of craters such as
1174:
McGill, G. E., and King, E. A., 1983, Geologic map of the Victoria quadrangle of Mercury: U.S. Geological Survey Miscellaneous Investigations Series Map I-1409, scale 1:5,000,000.
1298:
Wilhelms, D. E., and McCauley, J. F., 1971, Geologic map of the near side of the Moon: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-1703, scale 1:5,000,000.
155:
images are available for only the western hemisphere, from long 0° to about long 190° W. Mercury was in darkness beyond long 190° W. on March 29, 1974, when the first
1295:
Wilhelms, D. E., and El-Baz, Farouk, 1977, Geologic map of the east side of the Moon: U.S. Geological Survey Miscellaneous Investigations Series Map I-948, scale 1:5,000,000.
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Hartmann, W. K., 1967, Lunar crater counts, III: Post mare and âArchimedeanâ variations: Lunar and Planetary Laboratory, Communication no. 116, v. 7, pt. 3, p. 125â129.
70:
spacecraft, which orbited the planet from 2008 to 2015, excluding areas of permanent shadow near the north pole. Only approximately 25% of the quadrangle was imaged by the
99:
The east half of the mapped area (between long 0° and 100° W.) is characterized by smooth plains material (Murray and others, 1974). This unit covers vast expanses of
1301:
Wood, C. A., and Head, J. W., 1976, Comparison of impact basins on Mercury, Mars and the Moon: Lunar Science Conference, 7th, Houston, 1977, Proeedings, p. 3629â3651.
509:
Two types of ghost craters occur in the Borealis region; both are nearly obliterated by smooth plains material. In one type found along the northwest border of
1252:
Scott, D. H., 1972, Geologic map of the Maurolycus quadrangle of the Moon: U.S. Geological Survey Miscellaneous Investigations Map I-695, scale 1:1,000,000.
1331:
297:
3469:
506:
interiors of these large craters are filled with material that is less cratered, smoother, and therefore younger than the intercrater plains material.
397:
160:
geologic mapping were acquired during the third flyby on March 17, 1975. No stereoscopic photographic pairs are available for the Borealis region.
1140:
Malin, M. C., and Dzurisin, Daniel, 1977, Landform degradation on Mercury, the Moon, and Mars: Evidence from crater depth/diameter relationships:
215:
1088:
Dzurisin, Daniel, 1978, The tectonic and volcanic history of Mercury as inferred from studies of scarps, ridges, troughs, and other lineaments:
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Smith, E. I., and Hartnell, J. A., 1978, Crater-size-shape profiles for the Moon and Mercury: Terrain effects and interplanetary comparisons:
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such as may have existed on the Moon (Wood and others, 1970). If emplaced during later stages of mercurian evolution, it may consist of basin
585:
975:
Gault, D. E.; Guest, J. E.; Murray, J. B.; Dzurisin, D.; Malin, M. C. (1975). "Some comparisons of impact craters on Mercury and the Moon".
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and beyond. The scarps tend to be straight in intercrater plains material, but become notably lobate in crater fill (for example, within
196:(Klaasen, 1976; Murray and others, 1981, p. 28); its rotation period of 58.64 terrestrial days is in two-thirds resonance with its
1571:
1114:
Hapke, Bruce, Danielson, G. E., Jr., Klaasen, Kenneth, and Wilson, Lionel, 1975, Photometric observations of Mercury from Mariner 10:
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Murray, B. C., Strom, R. G., Trask, N. J., and Gault, D. E., 1975, Surface history of Mercury: Implications for terrestrial planets:
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The relative age of intercrater plains material has a bearing on its origin. If very old, intercrater plains material may consist of
1165:
McCauley, J. F., Guest, J. E., Schaber, G. G., Trask, N. J., and Greeley, Ronald, 1981, Stratigraphy of the Caloris Basin, Mercury:
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Schaber. G. G., Boyce, J. M., Trask, N.J., 1977, Moon-Mercury: Large impact structures, isostacy, an average crustal viscosity:
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Murray, B. C., Malin, M. C., and Greeley, Ronald, 1981, Earthlike planets: San Francisco, W. H. Freeman and Co., 387p.
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Malin, M. C., and Dzurisin, Daniel, 1978, Modification of fresh crater landforms: Evidence from the Moon and Mercury:
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One of the major differences between the mercurian and lunar surfaces is "the widespread distribution of lobate
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1340:
1288:
Stuart-Alexander, D. E., and Wilhelms, D. E., 1975, The Nectarian System: A new lunar time-stratigraphic unit:
53:
1217:
Pechmann, J. B., and Melosh, H. J., 1979 Global fracture patterns of a despun planet: Application to Mercury:
427:
surrounding the Caloris Basin in the Shakespeare quadrangle (Guest and Greeley, 1983), and to features of the
1963:
1521:
1459:
1385:
3459:
3282:
3252:
3146:
3121:
1435:
1409:
1359:
1272:
61:
2286:
2206:
1184:
Melosh, H. J., and Dzurisin, Daniel, 1978, Mercurian global tectonics: A consequence of tidal despining?:
226:
surface. The curve for the lunar uplands was derived from crater counts in the region northwest of crater
2186:
1629:
1591:
1485:
1447:
1373:
2726:
2731:
2526:
1973:
1497:
1471:
1423:
1243:
Schultz, P. H., and Gicken, Harry, 1979, Impact crater and basin control of igneous processes on Mars:
497:(Schaber and McCauley, 1980); this scarcity is also characteristic of the unit in the Borealis region.
2776:
3425:
1991:
1557:
1078:
193:
2086:
3227:
3131:
1535:
3151:
3381:
2871:
1708:
1504:
2281:
3314:
2681:
1718:
1392:
624:
from U.S. Geological Survey, Information Services, Box 25286, Federal Center, Denver, CO 80225)
389:
251:
177:
111:
2786:
3056:
2881:
2876:
2811:
2671:
2466:
2271:
2216:
2046:
2026:
1619:
305:
227:
3171:
200:
of 87.97 terrestrial days (Colombo, 1965; Colombo and Shapiro, 1966). The resulting lag and
3181:
3161:
3061:
2946:
2626:
2386:
2266:
2231:
2111:
2081:
2076:
1723:
1688:
1668:
1516:
1454:
1380:
892:
804:
239:
201:
115:
2936:
2031:
1920:
1769:
8:
3437:
3269:
3141:
3041:
3036:
2916:
2886:
2841:
2721:
2421:
2321:
2191:
2106:
2066:
1996:
1733:
1693:
1430:
1404:
576:
464:
401:
385:
255:
219:
173:
107:
2906:
2706:
2261:
896:
808:
3401:
3277:
3222:
3196:
3116:
3081:
3051:
3046:
2796:
2766:
2666:
2581:
2571:
2556:
2551:
2461:
2361:
2351:
2301:
2256:
2181:
2151:
2141:
2016:
2011:
1986:
1958:
1728:
1698:
1678:
1480:
1442:
1368:
1279:
Strom, R. G., 1977, Origin and relative age of lunar and mercurian intercrater plains:
675:
Strom, R. G.; Trask, N. J.; Guest, J. E. (1975). "Tectonism and volcanism on Mercury".
540:
494:
416:
377:
309:
231:
164:
119:
2236:
2121:
92:
small patches of smooth plains material are superposed on all other units. The crater
3433:
3016:
2941:
2866:
2806:
2761:
2756:
2746:
2741:
2686:
2591:
2586:
2546:
2481:
2451:
2446:
2436:
2416:
2376:
2336:
2316:
2241:
2201:
2176:
2101:
1789:
1774:
1713:
1703:
1683:
1492:
1466:
1418:
1198:
1107:
Hapke, Bruce, 1977, Interpretations of optical observations of Mercury and the Moon:
1034:
958:
931:
863:
838:
816:
552:
393:
326:
169:
100:
2846:
2131:
656:
405:
3186:
3166:
3076:
3026:
3021:
3006:
2991:
2981:
2961:
2956:
2896:
2861:
2856:
2851:
2826:
2816:
2801:
2771:
2736:
2716:
2656:
2651:
2636:
2606:
2601:
2596:
2536:
2471:
2456:
2431:
2426:
2406:
2391:
2371:
2366:
2341:
2306:
2251:
2246:
2211:
2171:
2136:
2061:
2056:
2021:
2006:
1915:
1905:
1885:
1852:
1847:
1819:
1804:
1784:
1580:
1219:
1167:
1011:
984:
954:
927:
900:
812:
772:
720:
684:
572:
periods following accretion are directly interpretable within the Borealis region.
548:
544:
502:
473:
446:
301:
280:
276:
243:
189:
57:
711:
Trask, N. J.; Guest, J. E. (1975). "Preliminary geologic terrain map of Mercury".
83:, whose diameter of at least 400 km (250 mi) makes it the sixth-largest
76:
spacecraft during its flybys in 1974 and 1975. The quadrangle is now called H-1.
3156:
3111:
3106:
3091:
3086:
3071:
3066:
2996:
2976:
2971:
2926:
2901:
2891:
2831:
2821:
2711:
2641:
2621:
2576:
2541:
2496:
2491:
2486:
2476:
2411:
2401:
2356:
2311:
2296:
2291:
2276:
2196:
2166:
2161:
2116:
2041:
1981:
1953:
1948:
1900:
1890:
1862:
1857:
1809:
1799:
1663:
1530:
1076:
Colombo, Giuseppe, and Shapiro, I. I., 1966, The rotation of the planet Mercury:
795:
Trask, N. J.; Strom, R. G. (1976). "Additional evidence of mercurian volcanism".
526:
510:
442:
428:
415:
No material similar to either the lineated or the secondary-crater facies of the
357:
259:
123:
1100:
Guest, J. E., and OâDonnell, W. P., 1977, Surface history of Mercury: A review:
400:, 130 km in diameter, centered at lat 64° N., long 77° W. in the
3201:
3191:
3176:
3136:
3101:
3096:
2986:
2966:
2951:
2931:
2921:
2911:
2836:
2791:
2781:
2751:
2701:
2696:
2691:
2676:
2646:
2616:
2611:
2566:
2561:
2521:
2511:
2501:
2396:
2381:
2346:
2331:
2226:
2221:
2156:
2126:
2091:
2071:
2051:
2036:
2001:
1925:
1842:
1837:
1751:
1270:
Solomon, S. C., 1978, On volcanism and thermal tectonics on one-plate planets:
1162:: National Aeronautics and Space Administration Special Publication 362, 255 p.
645:
589:
437:
424:
409:
197:
93:
3453:
3206:
3011:
3001:
2661:
2631:
2531:
2516:
2326:
2096:
1943:
1867:
1794:
1779:
531:
459:
432:
420:
373:
317:
292:
288:
988:
904:
724:
688:
3031:
2506:
2441:
2146:
1895:
1814:
1236:
Schultz, P. H., 1977, Endogenic modification of impact craters on Mercury:
368:
313:
235:
84:
80:
40:
19:
3347:
1309:
593:
337:
333:
642:
Radar imagery of Mercuryâs putative polar ice: 1999â2005 Arecibo results
137:
3332:
1910:
1015:
776:
522:
223:
151:
88:
72:
883:
Malin, M. C. (1976). "Observations of intercrater plains on Mercury".
3406:
3364:
3340:
477:
345:
321:
66:
24:
3292:
1069:
Colombo, Giuseppe, 1965, Rotational period of the planet Mercury:
1029:
Davies, M. E.; Dwornik, S. E.; Gault, D. E.; Strom, R. G. (1978).
858:
Davies, M. E.; Dwornik, S. E.; Gault, D. E.; Strom, R. G. (1978).
833:
Davies, M. E.; Dwornik, S. E.; Gault, D. E.; Strom, R. G. (1978).
1158:
Masursky, Harold, Colton, G. W., and El-Baz, Farouk, eds., 1978,
1033:. National Aeronautics and Space Administration. pp. 1â128.
581:
575:
Intercrater plains material, which may be a reworked and mixed
468:
341:
1002:
Strom, R. G. (1979). "Mercury: A post-Mariner 10 assessment".
763:
Strom, R. G. (1979). "Mercury: A post-Mariner 10 assessment".
458:
cratered compared to that of the intercrater plains material.
329:, and older than smooth plains material in Borealis Planitia.
837:. National Aeronautics and Space Administration. p. 31.
862:. National Aeronautics and Space Administration. p. 2.
64:
down to 65° latitude. It was mapped in its entirety by the
1549:
1177:
Melosh, H. J., 1977, Global tectonics of a despun planet:
1133:
Klaasen, K. P., 1976, Mercuryâs rotation axis and period:
945:
Wilhelms, D. E. (1976). "Mercurian volcanism questioned".
918:
Wilhelms, D. E. (1976). "Mercurian volcanism questioned".
1263:, v. 19, p. 479â511, 17 figs., 3 tables, appendices.
974:
640:
John K. Harmon, Martin A. Slade, Melissa S. Rice, 2011.
300:(Scott, 1972), whose base is defined as the base of the
1028:
857:
832:
218:, the most heavily cratered lunar surface, and that of
616:"Geologic Map of the Borealis Region (H-1) of Mercury"
613:
1146:, v. 82, no. 2, p. 376â 388, 7 figs., 7 tables.
180:(Guest and Greeley, 1983) quadrangles to the south.
828:
826:
106:Adjacent quadrangles to the south of Borealis are
3451:
823:
674:
657:Map of the H-1 (Borealis) Quadrangle of Mercury
419:, the most distinctive and distant unit of the
1123:Hartmann, W. K., 1966, Early lunar cratering:
1565:
1325:
614:Grolier, Maurice J.; Joseph M. Boyce (1984).
1282:Physics of the Earth and Planetary Interiors
1238:Physics of the Earth and Planetary Interiors
1228:Physics of the Earth and Planetary Interiors
1109:Physics of the Earth and Planetary Interiors
970:
968:
911:
758:
756:
754:
790:
788:
786:
752:
750:
748:
746:
744:
742:
740:
738:
736:
734:
706:
704:
702:
700:
698:
670:
668:
666:
664:
1572:
1558:
1339:
1332:
1318:
1290:U.S. Geological Survey Journal of Research
794:
710:
452:
3470:Surface features of Mercury by quadrangle
965:
436:1,100 km (680 mi) northeast of
269:
122:(270° to 0° W). It is opposite the
944:
917:
876:
783:
731:
695:
661:
592:) were modified considerably by further
136:
39:
30:
18:
1276:, v. 5, no. 6, p. 461â464, 3 figs.
1160:Apollo over the Moon: A view from orbit
3452:
604:(1977), Davies and others, and Strom.
372:similar to those occurring around the
320:unmantled terra and pre-Nectarian and
1553:
1514:
1502:
1490:
1478:
1452:
1440:
1428:
1402:
1390:
1378:
1366:
1313:
1001:
882:
762:
525:which appear to be thrust or reverse
23:Borealis quadrangle as mapped by the
1249:, v. 84, no. B14, p. 8033â8047.
1202:, v. 185, no. 4146, p. 169â179.
1094:, v. 83, no. B10, p. 4883â4906.
646:doi.org/10.1016/j.icarus.2010.08.007
129:
44:Mariner 10 image of the polar region
1285:, v. 15, nos. 2â3, p. 156â172.
1240:, v. 15, nos. 2â3, p. 202â219.
1230:, v. 15, nos. 2â3, p. 189â201.
1214:, v. 80, no. 17, p. 2508â2514.
566:
483:
13:
1120:, v. 80, no. 17, p. 2431â2443
535:nearly N-S in the polar regions."
363:
279:and south and southeast of crater
14:
3481:
1155:, v. 83, no. Bl, p. 233â243.
291:pitted plains south-southwest of
3432:
3421:
3420:
1223:, v. 38, no. 2, p. 243â250.
1188:, v. 35, no. 2, p. 227â236.
1181:, v. 31, no. 2, p. 221â243.
1171:, v. 47, no. 2, p. 184â202.
1137:, v. 28, no. 4, p. 469â478.
1073:, v. 208, no. 5010, p. 575.
192:is inclined less than 2° to its
1246:Journal of Geophysical Research
1211:Journal of Geophysical Research
1152:Journal of Geophysical Research
1143:Journal of Geophysical Research
1127:, v. 5, no.4, p. 406â 418.
1117:Journal of Geophysical Research
1091:Journal of Geophysical Research
1050:
1022:
995:
977:Journal of Geophysical Research
938:
713:Journal of Geophysical Research
677:Journal of Geophysical Research
208:
851:
650:
634:
1:
1964:Skinakas (hypothetical basin)
1292:, v. 3, no. 1, p. 53â58.
1043:. Special Publication SP-423.
872:. Special Publication SP-423.
847:. Special Publication SP-423.
628:
176:(McGill and King, 1983), and
3253:Hypothetical moon of Mercury
1273:Geophysical Research Letters
959:10.1016/0019-1035(76)90128-7
932:10.1016/0019-1035(76)90128-7
885:Geophysical Research Letters
817:10.1016/0019-1035(76)90129-9
516:
316:. This area is dominated by
7:
1579:
172:(De Hon and others, 1981),
118:(180° to 270° W), and
10:
3486:
3301:Mercury-crossing asteroids
1111:, v. 15, p. 264â 274.
1082:, v. 145, p. 296â307.
607:
183:
3415:
3394:
3374:
3357:
3322:
3313:
3291:
3268:
3261:
3245:
3215:
1972:
1934:
1876:
1828:
1760:
1742:
1654:
1638:
1607:
1600:
1587:
1528:
1464:
1416:
1352:
1347:
1104:, v. 20, p. 273â300.
1079:The Astrophysical Journal
242:and the lightly cratered
3465:Polar regions of Mercury
1261:The Moon and the Planets
644:. Icarus, 211, p37-50.
222:, a moderately cratered
149:In the Borealis region,
3382:Colonization of Mercury
989:10.1029/jb080i017p02444
905:10.1029/GL003i010p00581
725:10.1029/jb080i017p02461
689:10.1029/jb080i017p02478
596:following emplacement.
453:Younger plains material
384:and oldest of these is
1341:Quadrangles on Mercury
404:. The younger craters
390:Shakespeare quadrangle
270:Older plains materials
252:Shakespeare quadrangle
146:
114:(90° to 180° W),
112:Shakespeare quadrangle
45:
37:
28:
2727:Kuan Han-Chʻing
1004:Space Science Reviews
765:Space Science Reviews
472:similar to the lunar
140:
43:
34:
22:
16:Quadrangle on Mercury
2777:Li Chʻing-Chao
543:northward to crater
240:Mare Tranquillitatis
202:orbital eccentricity
116:Raditladi quadrangle
110:(0° to 90° W),
3460:Borealis quadrangle
3233:Inter-crater plains
1102:Vistas in Astronomy
897:1976GeoRL...3..581M
809:1976Icar...28..559T
402:Victoria quadrangle
220:Oceanus Procellarum
126:at the south pole.
108:Victoria quadrangle
50:Borealis quadrangle
1267:p. 29.3â29.6.
1016:10.1007/bf00221842
777:10.1007/bf00221842
495:Tolstoj quadrangle
417:Van Eyck Formation
378:Tolstoj quadrangle
308:bounded by crater
147:
120:Hokusai quadrangle
46:
38:
29:
3447:
3446:
3390:
3389:
3309:
3308:
3241:
3240:
2287:ChĆng ChʼĆl
2282:Chiang Kʻui
1921:Santa MarĂa Rupes
1790:Mearcair Planitia
1775:Borealis Planitia
1770:ApÄrangi Planitia
1547:
1546:
1542:
1541:
1040:978-1-114-27448-8
983:(17): 2444â2460.
869:978-1-114-27448-8
844:978-1-114-27448-8
719:(17): 2461â2477.
683:(17): 2478â2507.
553:Kuiper quadrangle
298:Janssen Formation
230:, between crater
101:Borealis Planitia
3477:
3436:
3424:
3423:
3320:
3319:
3266:
3265:
2787:Liang Kʻai
1992:Africanus Horton
1916:Resolution Rupes
1906:Enterprise Rupes
1886:Antoniadi Dorsum
1853:Goldstone Vallis
1848:Goldstone Catena
1820:Utaridi Planitia
1805:Stilbon Planitia
1785:Caloris Planitia
1605:
1604:
1574:
1567:
1560:
1551:
1550:
1350:
1349:
1334:
1327:
1320:
1311:
1310:
1045:
1044:
1031:Atlas of Mercury
1026:
1020:
1019:
999:
993:
992:
972:
963:
962:
942:
936:
935:
915:
909:
908:
880:
874:
873:
860:Atlas of Mercury
855:
849:
848:
835:Atlas of Mercury
830:
821:
820:
792:
781:
780:
760:
729:
728:
708:
693:
692:
672:
659:
654:
648:
638:
622:
620:
567:Geologic history
539:and from crater
532:tidal despinning
484:Crater materials
474:Cayley Formation
398:Monteverdi Basin
302:Nectarian System
254:, in the crater
244:Mare Serenitatis
190:equatorial plane
168:they did in the
79:It contains the
60:surrounding the
3485:
3484:
3480:
3479:
3478:
3476:
3475:
3474:
3450:
3449:
3448:
3443:
3411:
3386:
3370:
3353:
3324:
3305:
3287:
3257:
3237:
3211:
3132:Sholem Aleichem
1968:
1959:Rembrandt Basin
1954:Raditladi Basin
1949:Pantheon Fossae
1936:
1930:
1901:Discovery Rupes
1891:Adventure Rupes
1878:
1872:
1863:Haystack Vallis
1858:Haystack Catena
1830:
1824:
1810:Suisei Planitia
1800:Sobkou Planitia
1762:
1756:
1744:
1738:
1650:
1634:
1615:Albedo features
1596:
1583:
1578:
1548:
1543:
1533:
1519:
1507:
1495:
1483:
1469:
1457:
1445:
1433:
1421:
1407:
1395:
1383:
1371:
1357:
1343:
1338:
1308:
1053:
1048:
1041:
1027:
1023:
1000:
996:
973:
966:
943:
939:
916:
912:
891:(10): 581â584.
881:
877:
870:
856:
852:
845:
831:
824:
793:
784:
761:
732:
709:
696:
673:
662:
655:
651:
639:
635:
631:
618:
610:
569:
519:
511:Suisei Planitia
486:
455:
429:Alpes Formation
366:
364:Basin materials
358:Suisei Planitia
336:derived from a
272:
260:Suisei Planitia
211:
186:
141:Photomosaic of
135:
124:Bach quadrangle
17:
12:
11:
5:
3483:
3473:
3472:
3467:
3462:
3445:
3444:
3442:
3441:
3429:
3416:
3413:
3412:
3410:
3409:
3404:
3398:
3396:
3392:
3391:
3388:
3387:
3385:
3384:
3378:
3376:
3372:
3371:
3369:
3368:
3361:
3359:
3355:
3354:
3352:
3351:
3350:(2018âpresent)
3345:
3337:
3328:
3326:
3317:
3311:
3310:
3307:
3306:
3304:
3303:
3297:
3295:
3289:
3288:
3286:
3285:
3280:
3274:
3272:
3263:
3259:
3258:
3256:
3255:
3249:
3247:
3243:
3242:
3239:
3238:
3236:
3235:
3230:
3225:
3219:
3217:
3213:
3212:
3210:
3209:
3204:
3199:
3194:
3189:
3184:
3179:
3174:
3169:
3164:
3159:
3154:
3149:
3144:
3139:
3134:
3129:
3124:
3119:
3114:
3109:
3104:
3099:
3094:
3089:
3084:
3079:
3074:
3069:
3064:
3059:
3054:
3049:
3044:
3039:
3034:
3029:
3024:
3019:
3014:
3009:
3004:
2999:
2994:
2989:
2984:
2979:
2974:
2969:
2964:
2959:
2954:
2949:
2944:
2939:
2934:
2929:
2924:
2919:
2914:
2909:
2904:
2899:
2894:
2889:
2884:
2879:
2874:
2869:
2864:
2859:
2854:
2849:
2844:
2839:
2834:
2829:
2824:
2819:
2814:
2809:
2804:
2799:
2794:
2789:
2784:
2779:
2774:
2769:
2764:
2759:
2754:
2749:
2744:
2739:
2734:
2729:
2724:
2719:
2714:
2709:
2704:
2699:
2694:
2689:
2684:
2679:
2674:
2669:
2664:
2659:
2654:
2649:
2644:
2639:
2634:
2629:
2624:
2619:
2614:
2609:
2604:
2599:
2594:
2589:
2584:
2579:
2574:
2569:
2564:
2559:
2554:
2549:
2544:
2539:
2534:
2529:
2527:Guido d'Arezzo
2524:
2519:
2514:
2509:
2504:
2499:
2494:
2489:
2484:
2479:
2474:
2469:
2464:
2459:
2454:
2449:
2444:
2439:
2434:
2429:
2424:
2419:
2414:
2409:
2404:
2399:
2394:
2389:
2384:
2379:
2374:
2369:
2364:
2359:
2354:
2349:
2344:
2339:
2334:
2329:
2324:
2319:
2314:
2309:
2304:
2299:
2294:
2289:
2284:
2279:
2274:
2269:
2264:
2259:
2254:
2249:
2244:
2239:
2234:
2229:
2224:
2219:
2214:
2209:
2204:
2199:
2194:
2189:
2184:
2179:
2174:
2169:
2164:
2159:
2154:
2149:
2144:
2139:
2134:
2129:
2124:
2119:
2114:
2109:
2104:
2099:
2094:
2089:
2084:
2079:
2074:
2069:
2064:
2059:
2054:
2049:
2044:
2039:
2034:
2029:
2024:
2019:
2014:
2009:
2004:
1999:
1994:
1989:
1984:
1978:
1976:
1970:
1969:
1967:
1966:
1961:
1956:
1951:
1946:
1940:
1938:
1932:
1931:
1929:
1928:
1926:Victoria Rupes
1923:
1918:
1913:
1908:
1903:
1898:
1893:
1888:
1882:
1880:
1874:
1873:
1871:
1870:
1865:
1860:
1855:
1850:
1845:
1843:Arecibo Vallis
1840:
1838:Arecibo Catena
1834:
1832:
1826:
1825:
1823:
1822:
1817:
1812:
1807:
1802:
1797:
1792:
1787:
1782:
1777:
1772:
1766:
1764:
1758:
1757:
1755:
1754:
1752:Caloris Montes
1748:
1746:
1740:
1739:
1737:
1736:
1731:
1726:
1721:
1716:
1711:
1706:
1701:
1696:
1691:
1686:
1681:
1676:
1671:
1666:
1660:
1658:
1652:
1651:
1649:
1648:
1642:
1640:
1636:
1635:
1633:
1632:
1630:Magnetic field
1627:
1622:
1617:
1611:
1609:
1602:
1598:
1597:
1595:
1594:
1588:
1585:
1584:
1577:
1576:
1569:
1562:
1554:
1545:
1544:
1540:
1539:
1526:
1525:
1513:
1501:
1489:
1476:
1475:
1463:
1451:
1439:
1427:
1414:
1413:
1401:
1389:
1377:
1364:
1363:
1348:
1345:
1344:
1337:
1336:
1329:
1322:
1314:
1307:
1306:
1302:
1299:
1296:
1293:
1286:
1277:
1268:
1264:
1257:
1256:p. 28â30.
1253:
1250:
1241:
1234:
1231:
1224:
1215:
1206:
1203:
1189:
1182:
1175:
1172:
1163:
1156:
1147:
1138:
1131:
1128:
1121:
1112:
1105:
1098:
1095:
1086:
1083:
1074:
1067:
1063:
1059:
1054:
1052:
1049:
1047:
1046:
1039:
1021:
994:
964:
937:
926:(4): 551â558.
910:
875:
868:
850:
843:
822:
803:(4): 559â563.
782:
730:
694:
660:
649:
632:
630:
627:
626:
625:
609:
606:
590:impact breccia
568:
565:
518:
515:
485:
482:
460:Wrinkle ridges
454:
451:
438:Caloris Montes
425:Odin Formation
365:
362:
271:
268:
210:
207:
198:orbital period
185:
182:
134:
128:
15:
9:
6:
4:
3:
2:
3482:
3471:
3468:
3466:
3463:
3461:
3458:
3457:
3455:
3440:
3439:
3435:
3430:
3428:
3427:
3418:
3417:
3414:
3408:
3405:
3403:
3400:
3399:
3397:
3393:
3383:
3380:
3379:
3377:
3373:
3366:
3363:
3362:
3360:
3356:
3349:
3346:
3343:
3342:
3338:
3335:
3334:
3330:
3329:
3327:
3321:
3318:
3316:
3312:
3302:
3299:
3298:
3296:
3294:
3290:
3284:
3281:
3279:
3276:
3275:
3273:
3271:
3267:
3264:
3260:
3254:
3251:
3250:
3248:
3244:
3234:
3231:
3229:
3228:Ghost craters
3226:
3224:
3221:
3220:
3218:
3214:
3208:
3205:
3203:
3200:
3198:
3195:
3193:
3190:
3188:
3185:
3183:
3180:
3178:
3175:
3173:
3170:
3168:
3165:
3163:
3160:
3158:
3155:
3153:
3150:
3148:
3145:
3143:
3140:
3138:
3135:
3133:
3130:
3128:
3125:
3123:
3120:
3118:
3115:
3113:
3110:
3108:
3105:
3103:
3100:
3098:
3095:
3093:
3090:
3088:
3085:
3083:
3080:
3078:
3075:
3073:
3070:
3068:
3065:
3063:
3060:
3058:
3055:
3053:
3050:
3048:
3045:
3043:
3040:
3038:
3035:
3033:
3030:
3028:
3025:
3023:
3020:
3018:
3015:
3013:
3010:
3008:
3005:
3003:
3000:
2998:
2995:
2993:
2990:
2988:
2985:
2983:
2980:
2978:
2975:
2973:
2970:
2968:
2965:
2963:
2960:
2958:
2955:
2953:
2950:
2948:
2945:
2943:
2940:
2938:
2935:
2933:
2930:
2928:
2925:
2923:
2920:
2918:
2915:
2913:
2910:
2908:
2905:
2903:
2900:
2898:
2895:
2893:
2890:
2888:
2885:
2883:
2880:
2878:
2875:
2873:
2870:
2868:
2865:
2863:
2860:
2858:
2855:
2853:
2850:
2848:
2845:
2843:
2840:
2838:
2835:
2833:
2830:
2828:
2825:
2823:
2820:
2818:
2815:
2813:
2810:
2808:
2805:
2803:
2800:
2798:
2795:
2793:
2790:
2788:
2785:
2783:
2780:
2778:
2775:
2773:
2770:
2768:
2765:
2763:
2760:
2758:
2755:
2753:
2750:
2748:
2745:
2743:
2740:
2738:
2735:
2733:
2730:
2728:
2725:
2723:
2720:
2718:
2715:
2713:
2710:
2708:
2705:
2703:
2700:
2698:
2695:
2693:
2690:
2688:
2685:
2683:
2682:Judah Ha-Levi
2680:
2678:
2675:
2673:
2670:
2668:
2665:
2663:
2660:
2658:
2655:
2653:
2650:
2648:
2645:
2643:
2640:
2638:
2635:
2633:
2630:
2628:
2625:
2623:
2620:
2618:
2615:
2613:
2610:
2608:
2605:
2603:
2600:
2598:
2595:
2593:
2590:
2588:
2585:
2583:
2580:
2578:
2575:
2573:
2570:
2568:
2565:
2563:
2560:
2558:
2555:
2553:
2550:
2548:
2545:
2543:
2540:
2538:
2535:
2533:
2530:
2528:
2525:
2523:
2520:
2518:
2515:
2513:
2510:
2508:
2505:
2503:
2500:
2498:
2495:
2493:
2490:
2488:
2485:
2483:
2480:
2478:
2475:
2473:
2470:
2468:
2465:
2463:
2460:
2458:
2455:
2453:
2450:
2448:
2445:
2443:
2440:
2438:
2435:
2433:
2430:
2428:
2425:
2423:
2420:
2418:
2415:
2413:
2410:
2408:
2405:
2403:
2400:
2398:
2395:
2393:
2390:
2388:
2385:
2383:
2380:
2378:
2375:
2373:
2370:
2368:
2365:
2363:
2360:
2358:
2355:
2353:
2350:
2348:
2345:
2343:
2340:
2338:
2335:
2333:
2330:
2328:
2325:
2323:
2320:
2318:
2315:
2313:
2310:
2308:
2305:
2303:
2300:
2298:
2295:
2293:
2290:
2288:
2285:
2283:
2280:
2278:
2275:
2273:
2270:
2268:
2265:
2263:
2260:
2258:
2255:
2253:
2250:
2248:
2245:
2243:
2240:
2238:
2235:
2233:
2230:
2228:
2225:
2223:
2220:
2218:
2215:
2213:
2210:
2208:
2205:
2203:
2200:
2198:
2195:
2193:
2190:
2188:
2185:
2183:
2180:
2178:
2175:
2173:
2170:
2168:
2165:
2163:
2160:
2158:
2155:
2153:
2150:
2148:
2145:
2143:
2140:
2138:
2135:
2133:
2130:
2128:
2125:
2123:
2120:
2118:
2115:
2113:
2110:
2108:
2105:
2103:
2100:
2098:
2095:
2093:
2090:
2088:
2085:
2083:
2080:
2078:
2075:
2073:
2070:
2068:
2065:
2063:
2060:
2058:
2055:
2053:
2050:
2048:
2045:
2043:
2040:
2038:
2035:
2033:
2030:
2028:
2025:
2023:
2020:
2018:
2015:
2013:
2010:
2008:
2005:
2003:
2000:
1998:
1995:
1993:
1990:
1988:
1985:
1983:
1980:
1979:
1977:
1975:
1971:
1965:
1962:
1960:
1957:
1955:
1952:
1950:
1947:
1945:
1944:Caloris Basin
1942:
1941:
1939:
1933:
1927:
1924:
1922:
1919:
1917:
1914:
1912:
1909:
1907:
1904:
1902:
1899:
1897:
1894:
1892:
1889:
1887:
1884:
1883:
1881:
1875:
1869:
1868:Simeiz Vallis
1866:
1864:
1861:
1859:
1856:
1854:
1851:
1849:
1846:
1844:
1841:
1839:
1836:
1835:
1833:
1827:
1821:
1818:
1816:
1813:
1811:
1808:
1806:
1803:
1801:
1798:
1796:
1795:Odin Planitia
1793:
1791:
1788:
1786:
1783:
1781:
1780:Budh Planitia
1778:
1776:
1773:
1771:
1768:
1767:
1765:
1759:
1753:
1750:
1749:
1747:
1743:Mountains and
1741:
1735:
1732:
1730:
1727:
1725:
1722:
1720:
1717:
1715:
1712:
1710:
1707:
1705:
1702:
1700:
1697:
1695:
1692:
1690:
1687:
1685:
1682:
1680:
1677:
1675:
1672:
1670:
1667:
1665:
1662:
1661:
1659:
1657:
1653:
1647:
1644:
1643:
1641:
1637:
1631:
1628:
1626:
1623:
1621:
1618:
1616:
1613:
1612:
1610:
1606:
1603:
1599:
1593:
1590:
1589:
1586:
1582:
1575:
1570:
1568:
1563:
1561:
1556:
1555:
1552:
1537:
1532:
1527:
1523:
1518:
1511:
1506:
1499:
1494:
1487:
1482:
1477:
1473:
1468:
1461:
1456:
1449:
1444:
1437:
1432:
1425:
1420:
1415:
1411:
1406:
1399:
1394:
1387:
1382:
1375:
1370:
1365:
1361:
1356:
1351:
1346:
1342:
1335:
1330:
1328:
1323:
1321:
1316:
1315:
1312:
1303:
1300:
1297:
1294:
1291:
1287:
1284:
1283:
1278:
1275:
1274:
1269:
1265:
1262:
1258:
1254:
1251:
1248:
1247:
1242:
1239:
1235:
1232:
1229:
1225:
1222:
1221:
1216:
1213:
1212:
1207:
1204:
1201:
1200:
1195:
1190:
1187:
1183:
1180:
1176:
1173:
1170:
1169:
1164:
1161:
1157:
1154:
1153:
1148:
1145:
1144:
1139:
1136:
1132:
1129:
1126:
1122:
1119:
1118:
1113:
1110:
1106:
1103:
1099:
1096:
1093:
1092:
1087:
1084:
1081:
1080:
1075:
1072:
1068:
1064:
1060:
1056:
1055:
1042:
1036:
1032:
1025:
1017:
1013:
1009:
1005:
998:
990:
986:
982:
978:
971:
969:
960:
956:
952:
948:
941:
933:
929:
925:
921:
914:
906:
902:
898:
894:
890:
886:
879:
871:
865:
861:
854:
846:
840:
836:
829:
827:
818:
814:
810:
806:
802:
798:
791:
789:
787:
778:
774:
770:
766:
759:
757:
755:
753:
751:
749:
747:
745:
743:
741:
739:
737:
735:
726:
722:
718:
714:
707:
705:
703:
701:
699:
690:
686:
682:
678:
671:
669:
667:
665:
658:
653:
647:
643:
637:
633:
617:
612:
611:
605:
601:
597:
595:
591:
587:
583:
578:
573:
564:
560:
556:
554:
550:
546:
542:
536:
533:
528:
524:
514:
512:
507:
504:
498:
496:
490:
481:
479:
475:
470:
466:
461:
450:
448:
444:
439:
434:
433:Imbrium Basin
430:
426:
422:
421:Caloris Group
418:
413:
411:
407:
403:
399:
395:
391:
387:
381:
379:
375:
374:Caloris Basin
370:
361:
359:
353:
349:
347:
343:
339:
335:
330:
328:
323:
319:
318:pre-Nectarian
315:
311:
307:
303:
299:
294:
293:Mare Nectaris
290:
284:
282:
278:
267:
263:
261:
257:
253:
247:
245:
241:
237:
233:
229:
225:
221:
217:
216:lunar uplands
206:
203:
199:
195:
194:orbital plane
191:
181:
179:
175:
171:
166:
161:
158:
154:
153:
144:
139:
132:
127:
125:
121:
117:
113:
109:
104:
102:
97:
95:
90:
86:
82:
77:
75:
74:
69:
68:
63:
59:
55:
51:
42:
33:
26:
21:
3431:
3419:
3339:
3331:
3152:SveinsdĂłttir
3057:Rachmaninoff
2882:Michelangelo
2877:Mendes Pinto
2812:Ma Chih-Yuan
2467:Gainsborough
2272:Chao Meng-Fu
2217:Brunelleschi
2047:Amru Al-Qays
2027:Al-Hamadhani
1896:Beagle Rupes
1815:Tir Planitia
1709:Michelangelo
1673:
1505:Michelangelo
1354:
1289:
1280:
1271:
1260:
1244:
1237:
1227:
1218:
1209:
1197:
1193:
1185:
1178:
1166:
1159:
1150:
1141:
1134:
1124:
1115:
1108:
1101:
1089:
1077:
1070:
1062:p. 237.
1051:Bibliography
1030:
1024:
1010:(1): 10â11.
1007:
1003:
997:
980:
976:
950:
946:
940:
923:
919:
913:
888:
884:
878:
859:
853:
834:
800:
796:
768:
764:
716:
712:
680:
676:
652:
641:
636:
602:
598:
574:
570:
561:
557:
537:
520:
508:
499:
491:
487:
456:
414:
382:
369:Goethe Basin
367:
354:
350:
331:
314:Mare Smithii
306:Tsiolkovskiy
285:
273:
264:
248:
236:Mare Smithii
228:Tsiolkovskiy
212:
209:Stratigraphy
187:
163:Because the
162:
156:
150:
148:
142:
130:
105:
98:
87:observed on
85:impact basin
81:Goethe Basin
78:
71:
65:
49:
47:
3348:BepiColombo
3344:(2004â2015)
3336:(1973â1975)
3315:Exploration
3182:Villa-Lobos
3162:To Ngoc Van
3127:Shakespeare
3062:Raden Saleh
2947:Mussorgskij
2627:Hovnatanian
2387:Dostoevskij
2267:Chaikovskij
2232:Callicrates
2112:Baranauskas
2082:Aristoxenes
2077:Apollodorus
1829:Canyons and
1719:Shakespeare
1656:Quadrangles
1646:Quadrangles
1393:Shakespeare
771:(1): 3â70.
594:brecciation
586:impact melt
476:sampled by
431:around the
338:magma ocean
334:anorthosite
178:Shakespeare
3454:Categories
3333:Mariner 10
3142:Stravinsky
3042:Praxiteles
3037:Polygnotus
2917:Monteverdi
2887:Mickiewicz
2842:Mark Twain
2422:Enheduanna
2322:Cunningham
2192:Botticelli
2107:Balanchine
2067:Anguissola
1997:Ahmad Baba
1935:Basins and
1911:Hero Rupes
1877:Ridges and
1761:Plains and
1620:Atmosphere
1196:pictures:
1194:Mariner 10
953:(4): 556.
629:References
465:Archimedes
386:Botticelli
346:lava flows
256:Strindberg
224:lunar mare
188:Mercury's
165:terminator
157:Mariner 10
152:Mariner 10
143:Mariner 10
131:Mariner 10
89:Mariner 10
73:Mariner 10
62:north pole
54:quadrangle
27:spacecraft
3407:Sub-Earth
3365:Mercury-P
3341:MESSENGER
3293:Asteroids
3262:Astronomy
3197:Xiao Zhao
3172:VelĂĄzquez
3117:Scarlatti
3082:Rembrandt
3067:Raditladi
3052:Qi Baishi
3047:Prokofiev
2797:Lovecraft
2767:Lermontov
2667:Izquierdo
2582:Hiroshige
2572:Hemingway
2557:Hawthorne
2552:Hauptmann
2462:Futabatei
2362:Derzhavin
2352:Delacroix
2302:Coleridge
2257:Cervantes
2182:Boccaccio
2152:Belinskij
2142:Beethoven
2087:AĆvaghoáčŁa
2017:Al-Akhtal
2012:Akutagawa
1987:Abu Nuwas
1745:volcanoes
1724:Raditladi
1689:Discovery
1669:Beethoven
1601:Geography
1517:Discovery
1455:Beethoven
1381:Raditladi
577:aggregate
541:Van Dijck
517:Structure
478:Apollo 16
322:Nectarian
310:Mendeleev
232:Mendeleev
67:MESSENGER
25:MESSENGER
3426:Category
3375:See also
3358:Proposed
3325:and past
3270:Transits
3147:Sullivan
3122:Schubert
3017:Petrarch
2942:Murasaki
2937:MunkĂĄcsy
2867:Melville
2807:Lysippus
2762:Leopardi
2757:Larrocha
2747:Kurosawa
2742:Kunisada
2687:Kalidasa
2592:Hodgkins
2587:Hitomaro
2547:Harunobu
2482:Ghiberti
2452:Flaubert
2447:Firdousi
2437:Faulkner
2417:Eminescu
2377:Dominici
2337:De Graft
2317:Couperin
2242:Carducci
2202:Bramante
2187:Boethius
2177:Bjornson
2102:Balagtas
2032:Al-JÄhiz
1763:plateaus
1734:Victoria
1694:Eminescu
1674:Borealis
1625:Features
1536:features
1522:features
1510:features
1498:features
1486:features
1472:features
1460:features
1448:features
1436:features
1431:Eminescu
1424:features
1410:features
1405:Victoria
1398:features
1386:features
1374:features
1360:features
1355:Borealis
394:Turgenev
327:Turgenev
174:Victoria
3402:Fiction
3395:Related
3367:(~2031)
3323:Current
3223:Geology
3187:Vivaldi
3167:Tolstoj
3077:Raphael
3027:Picasso
3022:Phidias
3007:Oskison
2992:Neumann
2982:Nureyev
2962:Nampeyo
2957:Nabokov
2907:MoliĂšre
2897:Mistral
2862:Matisse
2857:Matabei
2852:Martial
2827:Mansart
2817:Machaut
2802:Lu Hsun
2772:Lessing
2737:Kulthum
2717:Kipling
2707:Kertész
2672:JanĂĄÄek
2657:Imhotep
2652:Ictinus
2637:Hun Kal
2607:Holberg
2602:Holbein
2597:Hokusai
2537:Han Kan
2472:Gauguin
2457:Flaiano
2432:Equiano
2427:Enwonwu
2407:Eastman
2392:Dowland
2372:Dickens
2367:Desprez
2342:Debussy
2307:Copland
2262:CĂ©zanne
2252:Calvino
2247:Carolan
2212:Bruegel
2172:Bernini
2137:Beckett
2062:Angelou
2057:Aneirin
2022:Alencar
2007:Aksakov
1974:Craters
1831:valleys
1729:Tolstoj
1699:Hokusai
1679:Debussy
1639:Regions
1608:General
1592:Outline
1581:Mercury
1481:Debussy
1443:Tolstoj
1369:Hokusai
1199:Science
1066:tables.
893:Bibcode
805:Bibcode
608:Sources
549:Saikaku
545:Purcell
503:Gauguin
447:Mansart
376:in the
289:Imbrian
281:Mansart
277:Gauguin
258:and in
184:Climate
58:Mercury
3438:Portal
3157:Titian
3112:Sander
3107:Rudaki
3092:Rivera
3087:Renoir
3072:Rameau
2997:Nizami
2977:Neruda
2972:Nawahi
2927:Mozart
2902:Mofolo
2892:Milton
2832:Mansur
2822:Mahler
2732:Kuiper
2712:Khansa
2642:Hurley
2622:Horace
2577:Hesiod
2542:Handel
2507:Goethe
2497:Glinka
2492:Giotto
2487:Gibran
2477:Geddes
2412:Eitoku
2402:Dvorak
2357:Derain
2312:Copley
2297:Chu Ta
2292:Chopin
2277:Chekov
2237:CamÔes
2207:Brontë
2197:Brahms
2167:Berkel
2162:Benoit
2122:BartĂłk
2117:Balzac
2042:Amaral
1982:Abedin
1937:fossae
1714:Neruda
1704:Kuiper
1684:Derain
1493:Neruda
1467:Kuiper
1419:Derain
1220:Icarus
1186:Icarus
1179:Icarus
1168:Icarus
1135:Icarus
1125:Icarus
1071:Nature
1037:
947:Icarus
920:Icarus
866:
841:
797:Icarus
582:basalt
527:faults
523:scarps
469:albedo
443:Nizami
342:ejecta
170:Kuiper
145:images
133:images
3278:Earth
3246:Moons
3216:Other
3202:Yeats
3192:Vyasa
3177:Verdi
3137:Sinan
3102:Rodin
3097:Rizal
2987:Nervo
2967:Navoi
2952:Myron
2932:Munch
2922:Moody
2912:Monet
2847:MartĂ
2837:March
2792:Liszt
2782:Li Po
2752:Lange
2722:KĆshĆ
2702:Kenko
2697:Keats
2692:Karsh
2677:Jokai
2647:Ibsen
2617:Homer
2612:Holst
2567:Heine
2562:Haydn
2522:Grieg
2512:Gogol
2502:Gluck
2397:Durer
2382:Donne
2347:Degas
2332:Dario
2227:Byron
2222:Burns
2157:Bello
2132:BashĆ
2127:Barma
2092:Atget
2072:Anyte
2052:Andal
2037:Alver
2002:Ailey
1879:rupes
1529:H-15
1515:H-11
1503:H-12
1491:H-13
1479:H-14
1417:H-10
619:(PDF)
588:, or
410:Verdi
406:JĂłkai
94:Verdi
52:is a
3283:Mars
3207:Zola
3012:Ovid
3002:Okyo
2872:Mena
2662:Ives
2632:Hugo
2532:Hals
2517:Goya
2327:Dali
2097:Bach
1664:Bach
1531:Bach
1465:H-6
1453:H-7
1441:H-8
1429:H-9
1403:H-2
1391:H-3
1379:H-4
1367:H-5
1353:H-1
1305:988.
1035:ISBN
864:ISBN
839:ISBN
408:and
312:and
287:pre-
234:and
48:The
36:ice.
3032:Poe
2442:Fet
2147:Bek
1012:doi
985:doi
955:doi
928:doi
901:doi
813:doi
773:doi
721:doi
685:doi
344:or
56:on
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