Below is the online edition of *In the Beginning: Compelling Evidence for Creation and the Flood*,
by Dr. Walt Brown. Copyright © Center for Scientific Creation. All rights reserved.

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At the time of the flood, about 3% of the Earth’s mass was launched into space. Most of that mass would have had enough velocity to escape the Earth’s sphere of influence and become comets and asteroids. A very small percentage of this debris (1.22%) hit the Moon. For this analysis it is assumed this mass was launched vertically from the surface of the Earth by the fountains of the great deep, with a velocity of 11.35 km/sec (or 7.05 miles/sec).

In addition to this vertical velocity, the debris would also have had an eastward velocity due to the Earth’s rotation. The Earth rotates today 0.4651 km/sec at the equator. Before the flood, it would have been rotating slower, resulting in 360 days in a year instead of today’s 365.242 days. For simplicity, this assumes Earth’s radius did not change at the time of the flood.

This mass would not necessarily have been launched near the equator though. Debris would have been launched from latitudes corresponding to those of today’s Mid-Oceanic Ridge. Because the angle between the Moon’s orbit and the equatorial plane is 18.28° – 28.58°, the debris that hit the Moon could have come from a narrow range of latitudes: 0° ± 28.58°. If the debris came from 28.58°, its eastward velocity would have been

There is no way to know if the debris was launched with a maximum eastward velocity of 0.4584 km/sec, a minimum velocity of 0.4025 km/sec, or some intermediate value. For now, we will assume the maximum velocity of 0.4584 km/sec. Later it will be shown that even if the minimum velocity was used, the final numbers would not change much.

If the debris that impacted the Moon left the Earth from the equator with an eastward velocity of 0.4584 km/sec and a vertical velocity of 11.35 km/sec, it would have had an equatorial orbit. Also, using the Pythagorean Theorem, the magnitude of the debris’ velocity would have been 11.35925 km/sec. This is consistent with the estimated average velocity of approximately 11.2 km/sec for asteroids and irregular Moons in Table 44 on page 615.

Using this velocity, along with the gravitational parameter of the Earth before the flood (µ_{EBF}), the specific mechanical energy of the debris was calculated. Here the subscript “D” indicates the debris’ orbit. It is assumed the mass that hit the Moon was still affected gravitationally by the other debris from the Earth. This is why the calculations below use the gravitational parameter before the flood, not after the flood.

This slightly positive specific mechanical energy indicates the orbit was barely hyperbolic relative to Earth, meaning the debris had just enough energy to escape the Earth’s gravitational field (based on the standard definition that potential energy is zero at an infinite distance from Earth). This allowed the semimajor axis of the debris’ orbit to be found.

As expected for a hyperbolic orbit, the semimajor axis is negative.

To calculate the debris’ eccentricity, the specific angular momentum had to be found. This is simply the distance the debris is from the center of the Earth times the velocity in the horizontal direction, which in this case is in the eastwardly direction found in Equation 8.

The parameter, p, for the debris’ orbit was then found.

This parameter of an orbit is also equal to a(1 - e^{2}), which allows the eccentricity to be found.

As previously mentioned, this is barely a hyperbolic orbit, so the eccentricity should be slightly greater than one.