R. Brown, PhD
Then God said, “Let there be lights in the expanse of the heavens to separate the day from the night, and let them be for signs, and for seasons, and for days and years and let them be for lights in the expanse of the heavens to give light on the Earth”; and it was so. And God made the two great lights, the greater light [the Sun] to govern the day, and the lesser light [the Moon] to govern the night; [Genesis 1:14–16a]
And God saw all that He had made, and behold it was very good. [Genesis 1:31]
Today, we have a 29.53-day lunar month.1 However, many ancient writings indicate that at one time there was a 30-day lunar month. Also, Genesis 7:11, 7:24, and 8:3-4 tell us that exactly 5 months elapsed during the first 150 days of the flood. This suggests that the preflood Earth may have had 30-day lunar months.
Even after the flood, many early calendars still used a 30-day month. Ancient Egyptian astronomers divided the year into three seasons, each with four 30-day months. Later, to achieve the known 365-day year, five days were added at the end of the year.2 The Falsi calendar in Asia Minor and India was similar.3 The early Greek and Syrian calendars were similar as well as the calendar established in the 4th century B.C. by Seleucus Necator, one of Alexander the Great’s generals. All of these calendars consisted of 12 months, each with exactly 30 days. Then five days were added to the end of the year to account for the 365-day year, and in some cases a sixth day was added every four years to account for leap year.4
Later, Mesopotamia adopted a calendar with 29-day months, which were called “hallow months” along with 30-day months, called “full months.” 5 The Greeks used a similar calendar and also called the 30-day months “full months” and the 29-day months “hallow months.” 6 Perhaps, 30-day months were called “full” and shorter months were “hallow,” because they believed at one time all months were 30 days in length.
References in the Vedic and classical Sanskrit texts explain why the length of a year and a month changed. These manuscripts point to a “cosmic upheaval in [the] remote past.” They explain that we used to have a 360-day year, but the Earth “underwent a total upheaval,” and as a result “the Earth’s period of revolution round the Sun in 360 days was changed to 365 days.” This also caused the Moon to undergo a “serious perturbation,” and “the period of lunation was very probably changed.” 7
Why did so many early cultures prefer a 30-day lunar month, and why do some Vedic and Sanskrit texts refer to a “cosmic upheaval” that altered the length of a year and the lunar month? Perhaps they heard stories passed down from Noah or one of his descendants. Noah lived for 448 years after the flood, and his son Shem lived for 500 years after the flood. [See Figure 247 on page 504.] The eight people who survived the flood lived a long time. No doubt they told many about the flood and how their lives had changed. They also probably helped establish calendars after the flood. If there was a 30-day month prior to the flood, it is very likely that this was initially the length of a month used after the flood.
As explained on pages 303-365, when the flood began, rocky debris, launched from Earth by the fountains of the great deep later merged to became comets, asteroids, and trans-Neptunian objects (TNOs). Some of that debris would have hit the Moon, primarily on the side nearest the Earth. That would have caused the “serious perturbation” that early Vedic and Sanskrit texts claimed altered “the period of lunation.”7 There is also physical evidence that debris from the Earth hit the Moon.
The Apollo 17 astronauts discovered that the Moon has an extremely thin atmosphere, about 10-14 that of Earth. These gases come from several sources, but the relatively large amount of oxygen was probably launched from Earth during the flood—some from dissociated water vapor that collided with the Moon, and some molecular oxygen dissolved in Earth’s surface water, as discovered on comet 67P. [See “Molecular Oxygen” on page 311.] Ice recently discovered on the moon falsifies theories on the Moon’s evolution, but is consistent with the hydroplate theory. The Moon is also much warmer than expected. [See “Hot Moon,” Endnote 84 on page 104 and Endnote 78 on page 334.] This extra heat is likely due to the recent impacts right after the flood. Finally, the tight clustering of lunar craters and their location on the side of the Moon facing the Earth indicates that the craters were formed by a rapid series of impacts coming from the same direction. Furthermore, these asteroids likely hit the side of the Moon facing Earth at the time. [See Figure 179 and Item 12 on page 322.] All of this physical evidence points to the strong possibility that the Moon was struck from debris recently launched from Earth.
Could these impacts have altered the Moon’s orbit, changing it from a 30-day lunar cycle to today’s 29.53-day lunar month? Could the Moon have had a perfectly circular (or “very good”) orbit, rather than today’s slightly elliptical orbit? How much of this debris launched from Earth would have had to impact the Moon to change its orbit to what we see today? These questions are answered in the following calculations that show if only 1.22% of the debris launched from the Earth hit the Moon, the lunar month would have changed from exactly 30 days before the flood to today’s 29.53-day lunar month. This percentage was determined by working the entire problem backwards, but it is presented here in chronological order for simplicity. Surprisingly, this would have also changed many of the Moon’s other key parameters to what we see today. [See Table 107 on page 334.]