Реферат: Theories Of The Origin Of The Moon

Subsequent calculations have been done at Harvard. The first set of

calculations

was intended to determine whether the revised hydrodynamics code reproduced

previous results (and it did). Subsequent calculations have been directed

toward

determining whether "successful" outcomes are possible with a wider range

of

initial conditions than were first used. The results indicate that the

impactor must

approach the Earth with a velocity (at large distances) of not more than

about 5

kilometers. This restricts the orbit of the impactor to lie near that of

the Earth. It

has also been found that collisions involving larger impactors with more

than the

Earth-Moon angular momentum can give "successful" outcomes. This initial

condition is reasonable because it is known that the Earth-Moon system has

lost

angular momentum due to solar tides, but the amount is uncertain. These

calculations are still in progress and will probably take 1 or 2 years more

to

complete

Bibliography

GIANT IMPACT THEORY OF THE ORIGIN OF THE MOON, A.G.W. Cameron,

Harvard-Smithsonian Center for Astrophysics, Cambridge MA 02138,

PLANETARY GEOSCIENCES-1988, NASA SP-498

EARTH’S ROTATION RATE MAY BE DUE TO EARLY COLLISIONS, Paula

Cleggett-Haleim, Michael Mewhinney, Ames Research Center, Mountain View,

Calif. RELEASE: 93-012