how does a moon formed?

Question

scientists says that the moon formed when a large asteroid collided with earth..if so,how come there is no earth's soil on the surface of moon? where does the moon come from? is it an alien type massive spaceship that resembles the moon just like the star wars 'death star'?

Answer 1

Interesting theory, but soil is a result of erosion and bacteria, which occurs on earth but not the moon (because there's no atmosphere there). When the moon separated from the earth (as the theory goes), the moon at the time was molten rock, and the other structures (such as craters on the moon and soil on the earth) formed later.

Answer 2

The latest theory, is, as you say, that the moon formed from a collision. But it was much larger than an asteroid. It was more likely that there were once two bodies in the same orbit as Earth. Us, and a planet the size of Mars. They eventually collided, and the Earth and Moon system is what remains. Check the link below.
This would have been when the Earth was still forming, perhaps still molten in parts, so any material from the moon would eventually get combined with Earth's minerals - it would be hard to tell them apart after 4 billion years.

Answer 3

Formation

Several mechanisms have been suggested for the Moon's formation.

Early speculation proposed that the Moon broke off from the Earth's crust because of centrifugal forces, leaving a basin (presumed to be the Pacific Ocean) behind as a scar. This fission concept, however, requires too great an initial spin of the Earth.

Others speculated that the Moon formed elsewhere and was captured into Earth's orbit. However, the conditions required for this capture mechanism to work (such as an extended atmosphere of the Earth for dissipating energy) are improbable.

The co-formation hypothesis posits that the Earth and the Moon formed together at the same time and place from the primordial accretion disk. In this hypothesis, the Moon formed from material surrounding the proto-Earth, similar to the formation of the planets around the Sun. Some suggest that this hypothesis fails to adequately explain the depletion of metallic iron in the Moon. A major deficiency with all of these hypotheses is that they cannot easily account for the high angular momentum of the Earth–Moon system.

Today, the giant impact hypothesis for forming the Earth–Moon system is widely accepted by the scientific community. In this hypothesis, the impact of a Mars-sized body on the proto-Earth is postulated to have put enough material into circumterrestrial orbit to form the Moon. Given that planetary bodies are believed to have formed by the hierarchical accretion of smaller bodies to larger ones, giant impact events such as this are thought to have affected most planets. Computer simulations of this impact are consistent with measurements of the angular momentum of the Earth–Moon system, as well as the small size of the lunar core. Unresolved questions regarding this theory have to do with determinate the relative sizes of the proto-Earth and impactor, and with determining how the material from the proto-Earth and the impactor was distributed when it formed the Moon. The formation of the Moon is believed to have occurred 4.527 ± 0.01 billion years ago, about 30–50 million years after the origin of the solar system.

No if it was a death star Darth Vader would rule the galexy with an army of Ewoks.

Answer 4

You were doing so well until your last question.......

There are four theories as to the creation of our Moon :

1. It coalesced from dust and debris in the same way as the Earth

2. It is a captured asteroid or mini-planet

3. When the Earth was created it was spinning so rapidly the Moon "spun" off it

4. The one finding most favour at the moment is that it was created when a planet the size of Mars collided with the Earth, breaking off the Moon but destroying itself entirely in the process

Funnily enough your theory that it is, in fact, an alien death star does not seem to appear on any of the NASA web sites.

Answer 5

In the decades since Apollo astronauts collected moon rocks, one theory has emerged over competing explanations of lunar birth the moon formed when a big object whacked Earth.

Scientists believe the solar system formed 4.56 billion years ago from a cloud or nebula of gas and dust surrounding the newborn sun. The nebula condensed into pebbles, rocks and larger "planetesimals," which collided and fused to create the planets.

A theory that the moon and Earth both condensed or accreted from the same material was rendered doubtful by a major difference in the moons composition the lack of a significant iron core like Earths.

Another theory said the moon formed elsewhere and was somehow captured by Earths gravity. But that seemed physically improbable and did not account for similarities in compositions of the moon and Earth.

The moons composition was enough like Earths mantle and crust to make some believe the moon formed from material hurled off of a rapidly spinning Earth. But hard evidence could not be found.

And none of the old theories explained how the moons oldest rocks solidified from molten rock about 4.44 billion years ago, roughly 100 million years after the solar system formed.

The giant impact theory proposed that at least 50 million years after the solar system formed, a large protoplanet whacked a perhaps still-molten Earth, heating and ejecting debris from both objects. Part of the debris then clumped together to form the moon, which was covered by molten rock from the heat of the collision.

Supercomputer simulations of the early solar system indicated in 1985 that the moon was not formed from huge solid chunks that were ripped off Earth. Instead, a planet-sized object hit a still-molten Earth, hurling into orbit a thick ring of vapor, dust and rocks, part of which clumped together to form the moon.

Data from the Clementine spacecraft, analyzed in 1995, showed the moon contained less iron than previously thought, and thus had a different bulk composition than Earth. That meant Earth and moon could not have accreted from the same nebula in the early solar system. Researchers argued the moon congealed from debris hurled into space by a giant impact.

In July 1997, University of Colorado, Boulder scientists said their computer simulations showed the object striking early Earth must have been three times more massive than Mars. Harvard University work in the 1980s had concluded the object was as massive as Mars.

More Colorado computer simulations, released in September 1997, mimicked conditions in a disk of debris blasted off early Earth by a giant impact. The simulations reveal the moon must have formed within a year after the collision, and at a distance of only 14,000 miles (22,500 kilometers) from Earth, a fraction of its present mean distance of 239,000 miles (384,600 kilometers).

University of Michigan chemists said in November 1997 that the decay of hafnium 182 to tungsten 182 in lunar samples indicated the moon-forming collision happened at least 50 million years after the solar system was born findings confirmed by a new study of other isotopes.

NASA reported in 1999 that gravity and magnetic-field measurements by the Lunar Prospector orbiter show the moons core is roughly 420 miles (680 kilometers) wide, or less than 4 percent of the moons mass. Earths iron core contains about 30 percent of the planets mass. NASA said the fact the cores are so different indicates the moon was made of material blasted off of Earths outer shell by a huge impact.

The early moons orbit was inclined about 10 degrees from Earths equator. Scientists at the Southwest Research Institute in Boulder, Colorado ran computer simulations to show how an object hitting Earth would throw debris into orbit, and some debris would start accreting to form the moon.

Gravitational interactions between the newborn moon and the remaining debris would have tilted the moons orbit, they found. The young moons inclined orbit had been a stumbling block for the impact theory because scientists thought an impact would produce the moon in equatorial orbit.