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| | **This solves the isotopic similarity and the relative lack of iron, but an analysis of the total angular momentum and energy involved ruled out this possibility. | | **This solves the isotopic similarity and the relative lack of iron, but an analysis of the total angular momentum and energy involved ruled out this possibility. |
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| − | For ten years after the lunar landings, non-creationist scientists lacked any accepted theory about the Moon's origin. In 1984, an international meeting was convened in Kona, Hawaii, for the purpose of agreeing on a new theory for the origin of the Moon.<ref>''Id.''</ref> The attendees at the meeting agreed upon the following "giant-impact model," which was first proposed in 1975 but which had not yet been generally accepted:
| + | == Giant-Impact Model == |
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| − | *An impact with a large planetesimal (asteroid-like body) released a great quantity of debris into orbit, a portion of which collected under the influence of gravity. There is no direct evidence for this theory. It is supported by non-creationist scientists, however, because only it might explain the following:
| + | For ten years after the lunar landings, non-creationist scientists lacked any accepted theory about the Moon's origin. In 1984, an international meeting was convened in Kona, Hawaii, for the purpose of agreeing on a new theory for the origin of the Moon.<ref>''Id.''</ref> The attendees at the meeting agreed upon the following "giant-impact model," which was first proposed in 1975 but which had not yet been generally accepted.<ref>''Id.''</ref> |
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| | + | This theory proposes an impact with a large planetesimal (asteroid-like body) released a great quantity of debris into orbit, a portion of which collected under the influence of gravity. There is no direct evidence for this theory. It is supported by non-creationist scientists, however, because only it might explain the following: |
| | **The lack of iron, provided the impact of the planetesimal happened relatively late in the earth's formation and after the Earth's iron had sunk towards its core. In that manner the Moon could pick up mantle from the Earth that has less iron. Most of the planetesimal itself would have sunk into the earth's core. | | **The lack of iron, provided the impact of the planetesimal happened relatively late in the earth's formation and after the Earth's iron had sunk towards its core. In that manner the Moon could pick up mantle from the Earth that has less iron. Most of the planetesimal itself would have sunk into the earth's core. |
| | **The similar oxygen isotope composition between the Moon and Earth could be explained by such a collision, provided the Moon were then formed from debris dislodged from the Earth by the collision. | | **The similar oxygen isotope composition between the Moon and Earth could be explained by such a collision, provided the Moon were then formed from debris dislodged from the Earth by the collision. |
| | **A high-velocity collision might be sufficient to release enough energy to place a substantial mass of the Earth's crust into orbit. | | **A high-velocity collision might be sufficient to release enough energy to place a substantial mass of the Earth's crust into orbit. |
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| | + | == Criticism of the Giant-Impact Model == |
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| | + | This new theory fail lacks testability and falsifiability, which are essential aspects of science as explained by [[Karl Popper]]. Scientists did find that none of three proposed tests are "supportive of the Giant Impact model."<ref>http://www.lpi.usra.edu/meetings/origin98/pdf/4045.pdf</ref> |
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| | But nearly two decades later, ''Scientific American'' observed that:<ref>http://www.sciam.com/article.cfm?chanID=sa006&colID=5&articleID=000A90B0-C919-1C6E-84A9809EC588EF21</ref> | | But nearly two decades later, ''Scientific American'' observed that:<ref>http://www.sciam.com/article.cfm?chanID=sa006&colID=5&articleID=000A90B0-C919-1C6E-84A9809EC588EF21</ref> |