Located on the far side of the Moon, Mare Ingenii makes up part of the South Pol-Aitken basin — a huge lunar feature that covers most of the southern hemisphere. The region contains the km wide Thomson crater. Insularum is hemmed in by the prominent Copernicus crater to the east, the Kepler crater to the west and joins up with the large Oceanus Procellarium in the southwest.
The northern edge is bordered by the Montes Carpatus while the south merges into Mare Cognitum. It was only named in Instead, it seems to have been a region of the highlands that was low enough for lava to reach the surface. It is covered with swirls of lighter material most likely reflecting the magnetic field present when the lava formed. One of the few lunar mare on the far side of the Moon, Moscoviense sits as a dark spot alone in the northern hemisphere.
Mare Nectaris is a small lunar mare just south of Mare Tranquillitatis, and bordered by the Montes Pyrenaeus along its eastern edge. Located to the southeast of Oceanus Procellarum, Mare Nubium is part of the pre-nectarian system, meaning it dates back to the earliest eras of the lunar surface. To the west lies the prominent Bullialdus crater. Mare Orientale is located in the basin created by an ancient meteor impact. The GRAIL mission found several large rift valleys created by tectonic faults cracking the land before being flooded with lava.
However, these are all buried beneath a remarkably featureless surface that is only peppered with small craters and only one large rayed crater, Kepler, at its centre. Rock samples returned by the Apollo 17 crew revealed that surface of the mare formed 3. Moore, P. Article Google Scholar. Download references. You can also search for this author in PubMed Google Scholar.
Reprints and Permissions. Origin of the Lunar Maria. Nature , Download citation. Published : 01 June Issue Date : 25 June Analyses of the returned samples show that the chemical composition of mare basalts varies across the Moon. These differences have also been correlated with the subtle color changes seen in spectral reflectance measurements; as a result, chemical variations can now be mapped far from the Apollo landing sites. The average diameter of the basin is about km.
Its generally circular outline is mimicked by the systems of arcuate rilles near the outer edge of the basin and also by the large system of mare ridges extending from arrow to arrow.
Another feature of Mare Serenitatis is the nearly continuous ring of dark mare material that occupies the outer part of its floor. When these pictures were taken, the Sun angle was too low to show differences in albedo clearly. The stratigraphic relationships between the dark and light mare units are described in figure 59, which is an enlargement of the small area outlined in this figure.
Accordingly, it has become a classic area for studying the sequence or stratigraphy of mare rocks. Earlier studies of telescopic photographs seemed to provide evidence that the lighter materials in the center of the basin top half of this view were emplaced before the darker lavas erupted along the basin margin.
However, pictures returned by Apollo 17 show that the opposite is true. The dark materials were emplaced first. They were then tilted northward and broken by faults, such as those that bound the Plinius Rilles, before the light lava flooded against them Howard et al. The large mare ridge or wrinkle ridge deforms both light and dark mare units but is much more prominent in the lighter unit.
Detailed spectral studies and visual observations by the Apollo 17 astronauts show that the lighter-toned mare is relatively browner and the darker mare is relatively bluer. Also shown is the Apollo 17 landing site large arrow in a dark-floored valley between bright mountain massifs. The rectangle surrounding the landing site outlines the area covered by the two maps that follow in figures 61 and The boundary between light mare material in the central part of the basin and the very dark mantling material surrounding the landing site area is indicated by several smaller arrows.
The difference in albedo is much more pronounced in this picture than in the mosaic fig. Before the Apollo 17 landing, the dark material was interpreted to be a blanket of pyroclastic debris volcanic cinders and ash.
It was thought to be as young as Copernican in age see fig. Analysis of samples returned from the Taurus-Littrow area has shown that while the dark material may be predominantly volcanic in origin, its age is considerably greater than had been predicted.
The dark mantling material most likely consists of black and orange glass beads that form a layer on top of the valley floor basalt and are reworked into the regolith, thus causing the low albedo. AS M. Lucchitta Scott, Lucchitta, and Carr, and published before Apollo 17 was launched. The actual landing point was very near the center of the large circle marking the proposed landing site.
Letter symbols and colors designate the different types of rock materials and their relative ages as deduced from study of photographs available before the mission. Some refinements could now be made based on samples and data gathered by the astronauts on the surface and from orbital experiments.
Apollo 15 panoramic camera photographs were the principal source of information for the original map, but mapping camera photographs, Orbiter pictures, and Earth-based telescopic pictures were also used. On the explanation accompanying the map, each unit is identified and its relative position in the lunar time scale is shown. The explanation on the original map also included a description of the physical characteristics of each unit and a Dotted where buried; buried unit in parathensis.
Bar and ball on downthrown side; dotted where buried. Line at base of slope, barb pointing downslope; solid where steep and high; open where gentle or low; may coincide with contact. Interpretation: steep scarp in most places marks break in slope located near buried fault. They are flatter regions than the surrounding uplands which is a result of the magma flowing and leveling before it cools and hardens to rock.
The magma that flowed out onto the craters contained iron, magnesium and titanium. Lower reflectivity means less light reaches our eyes from these areas than from the surrounding uplands, this is why the maria appear darker.
Yet, impact craters are uniformly seen on both sides of the Moon , so it took some time and further analysis to discover why there are fewer lunar maria on the dark side of the Moon. We now believe that the crust is twice as thick on the far side of the Moon , compared to the near side which always faces us. The crust is thicker scientists think because it cooled more quickly when the Moon was formed. The Earth and Moon were both huge lumps of molten rock when the Moon was created.
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