Navy P-8A Poseidon reconnaissance plane.
Volcanic features Lunar nearside with major maria and craters labeled The dark and relatively featureless lunar plains, clearly seen with the naked eye, are called maria Latin for "seas"; singular mareas they were once believed to be filled with water;  they are now known to be vast solidified pools of ancient basaltic lava.
Although similar to terrestrial basalts, lunar basalts have more iron and no minerals altered by water. Several geologic provinces containing shield volcanoes and volcanic domes are found within the near side "maria".
This raises the possibility of a much warmer lunar mantle than previously believed, at least on the near side where the deep crust is substantially warmer because of the greater concentration of radioactive elements. They have been radiometrically dated to having formed 4.
Although only a few multi-ring basins have been definitively dated, they are useful for assigning relative ages. Because impact craters accumulate at a nearly constant rate, counting the number of craters per unit area can be used to estimate the age of the surface.
The finer regolith, the lunar soil of silicon dioxide glass, has a texture resembling snow and a scent resembling spent gunpowder. A secondary cratering process caused by distal ejecta is thought to churn the top two centimetres of regolith a hundred times more quickly than previous models suggested—on a timescale of 81, years.
They are characterized by a high albedo, appear optically immature i. Their shape is often accentuated by low albedo regions that wind between the bright swirls. Presence of water Main article: Lunar water Liquid water cannot persist on the lunar surface. When exposed to solar radiation, water quickly decomposes through a process known as photodissociation and is lost to space.
However, since the s, scientists have hypothesized that water ice may be deposited by impacting comets or possibly produced by the reaction of oxygen-rich lunar rocks, and hydrogen from solar windleaving traces of water which could possibly persist in cold, permanently shadowed craters at either pole on the Moon.
However, later radar observations by Arecibosuggest these findings may rather be rocks ejected from young impact craters. The spectrometer observed absorption lines common to hydroxylin reflected sunlight, providing evidence of large quantities of water ice, on the lunar surface.
The inclusions were formed during explosive eruptions on the Moon approximately 3. Although of considerable selenological interest, this announcement affords little comfort to would-be lunar colonists—the sample originated many kilometers below the surface, and the inclusions are so difficult to access that it took 39 years to find them with a state-of-the-art ion microprobe instrument.
Analysis of the findings of the Moon Mineralogy Mapper M3 revealed in August for the first time "definitive evidence" for water-ice on the lunar surface. The main lunar gravity features are masconslarge positive gravitational anomalies associated with some of the giant impact basinspartly caused by the dense mare basaltic lava flows that fill those basins.
There are some puzzles: Magnetic field of the Moon The Moon has an external magnetic field of about 1— nanoteslasless than one-hundredth that of Earth.
The Moon does not currently have a global dipolar magnetic field and only has crustal magnetization, probably acquired early in its history when a dynamo was still operating. This is supported by the apparent location of the largest crustal magnetizations near the antipodes of the giant impact basins.
Atmosphere of the Moon Sketch by the Apollo 17 astronauts. Its sources include outgassing and sputteringa product of the bombardment of lunar soil by solar wind ions.Any man who may care to look at history will find it obvious that nations have always been the products of their people, and not once the way around.
Plato’s Influence on Western Civilization - Our country is built on a set of values derived from ancient civilizations, individuals, and city-states; both negative and positive attributes of these relics can be proven to have assisted in molding our government into a unique and prized entity.
One of the Largest, Old Established Sources, of Antique and Vintage Swords, Arms, Armour And Military Books in Europe. The Battle of Marathon (Greek: Μάχη τοῦ The Battle of Marathon was a watershed in the Greco-Persian wars, showing the Greeks that the Persians could be beaten; the eventual Greek triumph in these wars can be seen to begin at Marathon.
A negative view of Herodotus was passed on to Renaissance Europe, though he remained well read. Aug 21, · Watch video · The term “classical Greece” refers to the period between the Persian Wars at the beginning of the fifth century B.C. and the death of Alexander the Great in B.C.
The consequences of the Persian eventually led to Roman dominance. Thus they were extremely important in how western civilization evolved: 1. After the Persian Wars, Athens becomes a real imperialistic power in the region (they had already been fl.