Formation of the Moon: Theories

The _____ Theory states the Moon was formed elsewhere in the universe and was captured by the Earth's gravitational field when it came too close.

Capture

The _____ Theory states the Earth and Moon condensed at the same time from the nebula.

Condensation

The _____ Theory states when the Earth was young, it spun so fast that a piece of it broke off and was flung into space, where it became the Moon.

Fission

The _____ Theory , sometimes called the Colliding or Ejected Ring Theory, states the Earth was hit by something huge and a piece of Earth was ejected into space.

Giant Impact

The most accepted theory of the how the Moon was formed is the _____.

Giant Impact Theory

According to the Fission Theory, the _____ is the mostly likely site for the part of the Earth from which the Moon came.

Pacific Basin

It is believed the Condensation Theory is impossible because in other parts of the solar system when this happens, the two objects have similar (1)_____, but our Moon and Earth are different. The Earth contains significant amounts of metals and heavier elements, and the Moon is decidedly metal-poor. Another major problem is that the Moon seems to have formed about 100 million years _____ the Earth.

compositions, after

Many believe the Capture Theory to be impossible because it is unlikely that the two bodies would come together if created at a great (1)_____. If the Moon were speeding through the solar system, something would have to (2)_____ it down by just the right amount so that the Earth could capture it.

distance, slow

If the Fission Theory were true, the present-day Earth-Moon system should contain (1)_____ of this rapid spin, and it does not. Also, for this to be true, the Moon would have to be orbiting the Earth exactly on our (2)______, and it does not.

fossil evidence, orbital plane

According to the Capture Theory, the Moon's different chemical compositions can be explained because the moon traveled freely through space until it was captured by Earth's _____.

gravitational field

The Fission Theory was once thought possible because while the Moon doesn't have the same composition as the entire Earth, it does greatly resemble the outer _____of our planet.

layers

The Giant Impact Theory explains: - Why the Moon is made mostly of (1)_____. - Why the Moon is less (2)_____ and has less of the heavier elements than Earth does. - Why the Moon is (3)_____ million years younger than Earth. - Why the Moon isn't on the same (4)_____ plane as Earth.

rock, dense, 100, orbital