Moon

A moon is a natural satellite that orbits a planet or dwarf planet. The body known as The Moon is the particular object in orbit around the Earth, but nearly 200 other moons are known to exist in our solar system, in orbit around six of the eight planets and two of the dwarf planets (Pluto and Eris). For example, the Jupiter planet-moon system has more than sixty satellites, including its four largest, the Galilean moons. The Earth's moon is the brightest object in the night sky, reflecting the light from the sun.

The moon is the only astronomical body other than Earth ever visited by human beings.

Origin
Although many theories have been put forth to explain the origin of our moon and others in our solar system, their uniqueness argues strongly against the Big bang and nebula hypothesis, and instead offers strong evidence of design and recent creation.

Origin of Earth's Moon
The Bible states that the moon, like all non-earth celestrial bodies, was created by God on the fourth day of Creation.

Secular theories regarding the origin of Earth's moon are many and varied. They include the fission theory, the capture theory, and the accretion model. Walt Brown points out that the orbit of the Moon is severely inclined with respect to Earth's equator, and almost circular. Furthermore, the elemental composition of the Moon is markedly dissimilar from that of Earth. These facts provide strong evidence against the fission and capture theories. Brown also argues that the accretion theory cannot explain the absence of other particles closer to Earth than the Moon's orbit. The presence of such bodies would not necessarily be inconsistent with the Moon having "cleared its neighborhood" of small objects within its orbit.

The current favorite theory of secular scientists is the Giant Impact or "Big Whack" theory. According to this idea, Earth collided with a planet-sized object 4.6 billion years ago. A cloud of vaporized rock then shot off Earth's surface and went into orbit around Earth. The cloud cooled and condensed into a ring of small, solid bodies, which then gathered together, forming the moon. The rapid joining together of the small bodies released much energy as heat. Consequently, the moon melted, creating an "ocean" of magma (melted rock). The magma ocean slowly cooled and solidified. As it cooled, dense, iron-rich materials sank deep into the moon. Those materials also cooled and solidified, forming the mantle, the layer of rock beneath the crust.

Brown counters that if a Mars-sized object did impact the earth, then in order to produce an object as large as the Moon, it would also have made the Earth's day far shorter than it is. He also says that a giant impact should have produced more moons than the one we see.

Recently, some scientists have found a possible help for the fission theory by postulating a large natural nuclear explosion. They argue that a large fission reaction like the Oslo reactor could have provided the impetus for a split in the primordial spinning blob that became earth.

Biblical
The Bible implies that many of the other moons were created together with the planets they orbit in Day 4 of creation. Evidence of system-wide catastrophes occurring a few centuries after the fall of man and the global flood suggests that at least some of the moons might have begun as part of one or the other catastrophe and then fallen into orbit around their respective planets. Any such moons would have to be in orbits that were more eccentric than average, or more inclined with respect to their primaries' equators, or both.

Secular
Theories of the origins of moons other than Earth are almost as varied as the number of those moons. Astronomers believe that Mars's moons Phobos and Deimos, for example, are captured asteroids. The gas giant planets (Jupiter, Saturn, Uranus, and Neptune) have many more moons, and many of these are no larger than Phobos or Deimos. But several others, such as the Galilean moons and the largest moons of Saturn are the size of dwarf planets. Some, like Ganymede and Titan, are larger even than Mercury, the smallest of the true planets. Furthermore, the surfaces of some of these larger moons have not suffered as much bombardment as have those of others. By uniformitarian standards, then, such moons are considered relatively "young."

Three of the Jupiter's moons (Io, Europa, and Ganymede) have a orbital resonance that becomes very difficult to explain in light of Ganymede appearing to be so much "older" than Io or Europa. (Callisto, the fourth of the Galileans, does not participate.) At least some astronomers believe that this resonance is primordial. Not all astronomers agree. But if the resonance is primordial, then the presence within it of bodies of differing "geological ages" begs explanation.

Purpose
The most obvious purposes of the moon of Earth are stated in Genesis 1, as being a lesser light to govern the night, and a sign(s) to mark seasons. There are, however, many other import purposes for the moon, which include stabilizing the tilt of the Earth, and driving the movement of fluids such as the ocean waters.

Sign to Mark Seasons
Our calendar month is based on the orbit of the moon (a sign(s) to mark seasons). The moon revolves around Earth once with respect to the sun in about 29 1/2 days, a period known as a synodic month. As the moon orbits Earth, the moon appears to change shape because the observer sees different parts of the moon's sunlit surface as the moon orbits Earth. The different appearances are known as the phases of the moon. The moon goes through a complete cycle of phases in a synodic month.

The moon has four phases: (1) new moon, (2) first quarter, (3) full moon, and (4) last quarter. When the moon is between the sun and Earth, its sunlit side is turned away from Earth. Astronomers call this darkened phase a new moon.



The next night after a new moon, a thin crescent of light appears along the moon's eastern edge. The remaining portion of the moon that faces Earth is faintly visible because of earthshine, sunlight reflected from Earth to the moon. Each night, an observer on Earth can see more of the sunlit side. After about seven days, the observer can see half a full moon, commonly called a half moon. This phase is known as the first quarter because it occurs one quarter of the way through the synodic month. About seven days later, the moon is on the side of Earth opposite the sun. The entire sunlit side of the moon is now visible. This phase is called a full moon. About seven days after a full moon, the observer again sees a half moon. This phase is the last quarter, or third quarter. After another seven days, the moon is between Earth and the sun, and another new moon occurs.

Like the sun, the moon rises in the east and sets in the west. As the moon progresses through its phases, it rises and sets at different times. In the new moon phase, it rises with the sun and travels close to the sun across the sky. Each successive day, the moon rises an average of about 50 minutes later.

Eclipses occur when Earth, the sun, and the moon are in a straight line, or nearly so. A lunar eclipse occurs when Earth gets directly -- or almost directly -- between the sun and the moon, and Earth's shadow falls on the moon. A lunar eclipse can occur only during a full moon. A solar eclipse occurs when the moon gets directly -- or almost directly -- between the sun and Earth, and the moon's shadow falls on Earth. A solar eclipse can occur only during a new moon.

Orbital
The moon is characterized by its synchronous rotation where the moon rotates on its axis once per month while remarkably revolving around the earth at the same rate of once per month. As a result, from the perspective of the earth, the same side of the moon is constantly visible and the back side of the moon is never visible from earth. By comparison, the earth rotates on its axis once per day and revolves around the sun once per year. The phenomenon of synchronous rotation has been attributed to the physics of tidal lock. Many other moons in the solar system also display tidal lock and artificial satellites above earth are also stabilized in their orbits by tidal lock.

All available evidence suggests that the moon has been in tidal lock since creation.

Size
The moon is much smaller than Earth. The moon's average radius (distance from its center to its surface) is 1,079.6 miles (1,737.4 kilometers), about 27 percent of the radius of Earth. The moon is also much less massive than Earth. The moon has a mass (amount of matter) of 8.10 x 1019 tons (7.35 x 1019 metric tons). Earth is about 81 times that massive. The moon's density (mass divided by volume) is about 3.34 grams per cubic centimeter, roughly 60 percent of Earth's density.

Because the moon has less mass than Earth, the force due to gravity at the lunar surface is only about 1/6 of that on Earth. Thus, a person standing on the moon would feel as if his or her weight had decreased by 5/6. And if that person dropped a rock, the rock would fall to the surface much more slowly than the same rock would fall to Earth. Despite the moon's relatively weak gravitational force, the moon is close enough to Earth to produce tides in Earth's waters.

Surface Features
A person on Earth looking at the moon with the unaided eye can see light and dark areas on the lunar surface. The light areas are rugged, cratered highlands known as terrae (TEHR ee). The word terrae is Latin for lands. The highlands are the original crust of the moon, shattered and fragmented by the impact of meteoroids, asteroids, and comets. Many craters in the terrae exceed 25 miles (40 kilometers) in diameter. The largest is the South Pole-Aitken Basin, which is 1,550 miles (2,500 kilometers) in diameter. The dark areas on the moon are known as maria (MAHR ee uh). The word maria is Latin for seas; its singular is mare (MAHR ee). The term comes from the smoothness of the dark areas and their resemblance to bodies of water. The maria are cratered landscapes that were partly flooded by lava when volcanoes erupted. The lava then froze, forming rock. Since that time, meteoroid impacts have created craters in the maria.

Craters

 * Main Article: Impact crater

The moon's craters that were formed by the impact of meteoroids, asteroids, and comets. The shape of craters varies with their size. Small craters with diameters of less than 6 miles (10 kilometers) have relatively simple bowl shapes. The walls of slightly larger craters become scalloped and the floor becomes flat. Still larger craters have terraced walls and central peaks. Surrounding the craters is rough, mountainous material -- crushed and broken rocks that were ripped out of the crater cavity by shock pressure. This material, called the crater ejecta blanket, can extend about 60 miles (100 kilometers) from the crater. Farther out are patches of debris and, in many cases, irregular secondary craters.

Craters larger than about 120 miles (200 kilometers) across tend to have central mountains. Some of them also have inner rings of peaks, in addition to the central peak. The appearance of a ring signals the next major transition in crater shape -- from crater to basin. Basins are craters that are 190 miles (300 kilometers) or more across. The smaller basins have only a single inner ring of peaks, but the larger ones typically have multiple rings. The rings are concentric -- that is, they all have the same center, like the rings of a dartboard. The spectacular, multiple-ringed basin called the Eastern Sea (Mare Orientale) is almost 600 miles (1,000 kilometers) across. Other basins can be more than 1,200 miles (2,000 kilometers) in diameter -- as large as the entire western United States. Basins occur equally on the near side and far side.

Maria
Another prominent feature of the moon are the dark areas known as Maria, which make up about 16 percent of the surface area. Landforms on the maria tend to be smaller than those of the highlands. The small size of mare features relates to the scale of the processes that formed them -- volcanic eruptions and crustal deformation, rather than large impacts. The chief landforms on the maria include wrinkle ridges and rilles and other volcanic features. Wrinkle ridges are blisterlike humps that wind across the surface of almost all maria. The ridges are actually broad folds in the rocks, created by compression. Many wrinkle ridges are roughly circular, aligned with small peaks that stick up through the maria and outlining interior rings. Circular ridge systems also outline buried features, such as rims of craters that existed before the maria formed.

Volcanoes
Scattered throughout the maria are a variety of other features formed by volcanic eruptions. Within Mare Imbrium, scarps (lines of cliffs) wind their way across the surface. The scarps are lava flow fronts, places where lava solidified, enabling lava that was still molten to pile up behind them. The presence of the scarps is one piece of evidence indicating that the maria consist of solidified basaltic lava. Small hills and domes with pits on top are probably little volcanoes. Both dome-shaped and cone-shaped volcanoes cluster together in many places, as on Earth. One of the largest concentrations of cones on the moon is the Marius Hills complex in Oceanus Procellarum (Ocean of Storms). Within this complex are numerous wrinkle ridges and rilles, and more than 50 volcanoes.

Recession

 * Main Article: Moon recession

The average distance from the center of Earth to the center of the moon is 238,897 miles (384,467 kilometers). That distance is growing -- but extremely slowly. The moon is moving away from Earth at a speed of about 1 1/2 inches (3.8 centimeters) per year. Based on current measurements and estimates the moon would have been in contact with Earth approximately 1.2 billion years ago. This recession puts an upper limit on the age of the Earth / Moon system as being much younger than the 4.6 billion years it is estimated to be.

Impact Craters

 * ''Main Article: Lunar impact craters

Evolutionists assume that the age of a planet or moon can be estimated based on crater impacts. However, this assumes uniform constants and weather/erosion trends. Recent research into crater impacts on the moon has led to a greater understanding of their formation and age, suggesting that space weathering "takes place very rapidly on the Moon," according to Bonnie Buratti of NASA's Jet Propulsion Laboratory. This in turn has led scientists to make older date estimations by using inaccurate assumptions on space weathering. Other scientists, such as Peter Brown of the University of Western Ontario, insist that there is no absolute criteria for the dating of craters.

Danny Faulkner has observed that many of the lunar maria contain ghost craters, or craters that the lava flow that produced the maria seem to have filled only partially. In the deep time scale required by uniformitarianism, the ghost craters are the result of impacts that occurred as much as half a gigayear before the crust-fracturing impacts that caused the lava flows. This is not a reasonable assumption, because any impact strong enough to crack the crust should have obliterated any craters previously extant. Faulkner thus concludes that the impacts that formed the ghost craters, and those that let loose the lava flows that formed the maria, occurred within days of one another and were probably part of at least one system-wide catastrophe involving a narrow stream of meteoroids and/or comets that delivered a concentrated bombardment of the Earth and Moon in a short interval.

Faulkner assumes that this system-wide catastrophe occurred during the year of the global flood. But Russell Humphreys, in 1984, developed evidence suggesting different dates entirely. Specifically, the Apollo Program exploration teams brought back many samples of basalt (an igneous rock) and brecchia (pulverized meteor-impact remains). Geologists analyzed both types of samples and found evidence that each type of rock had once been in a magnetic field far more powerful than that which the Moon has today. Using his model for the creation and decay of magnetic fields, Humphreys determined that the basalt had been laid down about 370 years after creation, and the brecchia had been laid down 1840 years after creation, or about 190 years after the Flood. These findings clearly suggest that the Moon, and presumably all other bodies in the solar system, have been subject to two separate system-wide bombardments, one occurring in the second or third generation after the fall of man and the other occurring well after the Flood.

The far side of the moon is far more heavily cratered than the near, and the predominant type of cratering is consistent with brecchia-forming meteor impact. This would suggest that the far side suffered its bombardment in the latter of the two catastrophes.

Transient lunar phenomena

 * Main Article: Transient lunar phenomena

Throughout recorded history, people have been sighting changes in brightness on the surface of the moon. These changes, now known as Transient lunar phenomena, come in many forms and are attributed to releasing of gas or volcanic matter from under the moon's crust. According to NASA, there have been 579 reported incidents since the 1600s. These events are relatively small and last only a few hours. Thorough documentation has been difficult because in most cases the events have ended by the time they are reported. Astronomers have historically gone by secondhand observations when compiling data. All the known information suggests that they must be some form of volcanic discharge.

Episodic volcanism
Until recently, most geologists had thought that volcanism on the far side was confined to one period, which ended 3.0 billion years ago according to conventional dating. Then in 2008 recent photographs from the far side showed evidence of volcanism occurring at a more recent period, 2.5 billion years ago (conventional). This finding has led its discoverers to speculate that the volcanism on the Moon lasted longer than previously supposed and might have been episodic.

Latent Heat
Io, a moon of Jupiter, has puzzled evolutionists because of its extensive heat. According to old-earth beliefs, this moon should have cooled long ago. In fact, Io is the most volcanically active object in all the solar system. Most observers consider that Io is older than it looks, because the volcanoes and their associated lava flows have erased the craters. But that cannot apply to Europa, which looks at least as "young" as does Io. Io's volcanism testifies to its tremendous internal heat. In fact, Io is radiating far more heat than tidal heating alone could generate. And yet no astronomer accepts radioactive decay as a significant source of Io's heat. Either Io has another, still-unknown source of heat, or else the present rate of heat outflow is unsustainable and temporary.

Ancient Ideas
Some ancient peoples believed that the moon was a rotating bowl of fire. Others thought it was a mirror that reflected Earth's lands and seas. But philosophers in ancient Greece understood that the moon is a sphere in orbit around Earth. They also knew that moonlight is reflected sunlight. Some Greek philosophers believed that the moon was a world much like Earth. In about A.D. 100, Plutarch even suggested that people lived on the moon. The Greeks also apparently believed that the dark areas of the moon were seas, while the bright regions were land.

In about A.D. 150, Ptolemy, a Greek astronomer who lived in Alexandria, Egypt, said that the moon was Earth's nearest neighbor in space. He thought that both the moon and the sun orbited Earth. Ptolemy's views survived for more than 1,300 years. But by the early 1500's, the Polish astronomer Nicolaus Copernicus had developed the correct view -- Earth and the other planets revolve about the sun, and the moon orbits Earth.

Early observations with telescopes


The Italian astronomer and physicist Galileo wrote the first scientific description of the moon based on observations with a telescope. In 1609, Galileo described a rough, mountainous surface. This description was quite different from what was commonly believed -- that the moon was smooth. Galileo noted that the light regions were rough and hilly and the dark regions were smoother plains.

The presence of high mountains on the moon fascinated Galileo. His detailed description of a large crater in the central highlands -- probably Albategnius -- began 350 years of controversy and debate about the origin of the "holes" on the moon.

Other astronomers of the 1600's mapped and cataloged every surface feature they could see. Increasingly powerful telescopes led to more detailed records. In 1645, the Dutch engineer and astronomer Michael Florent van Langren, also known as Langrenus, published a map that gave names to the surface features of the moon, mostly its craters. A map drawn by the Bohemian-born Italian astronomer Anton M. S. de Rheita in 1645 correctly depicted the bright ray systems of the craters Tycho and Copernicus. Another effort, by the Polish astronomer Johannes Hevelius in 1647, included the moon's libration zones.

By 1651, two Jesuit scholars from Italy, the astronomer Giovanni Battista Riccioli and the mathematician and physicist Francesco M. Grimaldi, had completed a map of the moon. That map established the naming system for lunar features that is still in use.

Space missions
After the Second World War, both the United States and the Soviet Union sent robotic probes to the Moon for closer study. These included both orbiters and landers. Sporadic missions to the Moon continue to this day, the latest being the Clementina and Lunar Prospector missions, which confirmed the presence of a large formation of apparent water ice in the South Pole-Aitken Basin.

By far the most successful and valuable missions to the Moon were the Apollo Program missions, in which astronauts landed on the Moon. Six three-man teams succeeded in landing two members of each team on the Moon and gathering and returning multiple samples from both the maria and the highlands. The evidence of these samples constitutes some of the strongest evidence yet found for a young solar system.