How often have we heard the phrase that something will not happen until hell freezes over? The phrase is always used to refer to things that are impossible.
The earliest era of Earth’s history is referred to as the Hadean era, the epoch when Earth’s surface was hellishly hot. Planetary astronomers believe Earth’s surface had to be hellishly hot because of the intense bombardment of Earth at that time by planetesimals, asteroids, and comets.
What the New Evidence Shows
A recently published paper by three University of Colorado astronomers presents the first-ever dynamically self-consistent model for the formation of the Moon’s tidal-rotational bulge. This model provides evidence that previous to four billion years ago, Earth’s hydrosphere, rather than being hot steam, was, in fact, predominantly frozen.1
The Moon’s gravity raises up tides in Earth’s oceans from just a few inches in the Mediterranean, Baltic, and Caribbean Seas to a maximum of 53 feet high in Canada’s Bay of Fundy. Earth’s tidal forces on the Moon are much stronger than the Moon’s tidal forces on Earth. In the past, they were even stronger. Earth’s gravity has raised up solid rock tides on the Moon that are more than a kilometer high.
In 1799 the famed French astronomer and mathematician Pierre Simon Laplace determined that the Moon’s tidal-rotational bulge is about twenty times too big to be explained by present hydrostatic, tidal, and rotational forces.2 Thus, for the past two centuries scientists have theorized that the Moon was born hot, was much closer to Earth, and was rotating much more rapidly. These conditions would have generated the tidal-rotational bulge that astronomers observe today. The theories suggested that as the Moon cooled from its primordial state, the cooling solidified a permanent bulge. The primordial tidal-rotational bulge fossilized into the present tidal-rotational bulge. Astronomers today refer to the Moon’s equatorial bulge as the fossil bulge.
The University of Colorado astronomers’ model demonstrated that the formation of the Moon’s fossil bulge was controlled by (1) the timing of the thickening of the Moon’s lithosphere (outermost rocky shell or crust), and (2) by the recession of the Moon’s orbit away from Earth. For the first time, the model enabled astronomers to put timescale constraints on the Moon’s early recession from Earth and to determine the timing of the formation of the Moon’s fossil bulge.
The model produced by the three astronomers showed that the fossilization of the Moon’s bulge was not a rapid process. It was a slow process that lasted several hundred million years. Nevertheless, the fossilization was completed 4 billion years ago when the distance between the Moon and Earth was only about 128,000 miles. (Present average distance between the Moon and Earth = 239,000 miles.)
The model established that, for the fossilization of the Moon’s tidal-rotational bulge to take as long as it did, Earth during the Hadean era (4.5–4.0 billion years ago) had to be significantly less dissipative to lunar tides than it was during the past 4.0 billion years. This conclusion is surprising, since the Moon’s distance from Earth during the Hadean era was about half of what it is now. The closer proximity of the Moon implies that the tidal forces the Moon exerted during the Hadean era were about eight times stronger than they are today.
In the context of much stronger lunar tidal forces exerted on Earth, for Earth to be less dissipative to lunar tides its water had to be predominantly in a frozen state. A frozen Earth previous to 4.0 billion years ago conflicts with the notion of a hot one from asteroid and comet collisions. It would be consistent, however, with the Sun being 30 percent fainter at that time
Once the Sun’s mass stabilizes shortly after its formation, the fusion of hydrogen into helium in its nuclear furnace causes the Sun’s nuclear furnace to burn progressively more efficiently. Figure 1 shows the consequent brightening of the Sun throughout its early history.
Figure 1: Sun’s Brightness throughout Its History
image credit: Hugh Ross
Given how faint the Sun was previous to 4 billion years ago, all of Earth’s surface water, independent of collision events, would have been frozen. Figure 2 shows the history of collision events throughout Earth’s history that astronomers had calculated from their solar system formation models.
Figure 2: Old Bombardment Model of Earth throughout Its Early History. The spike at 3.9 billion years ago represents the late heavy bombardment. Heat from colliders previous to the late heavy bombardment would have prevented the formation of any ice.
image credit: Hugh Ross
Analysis of ancient zircons affirms that liquid water was present on Earth, at least for brief episodes in certain locales previous to 4 billion years ago.3 The new model for the formation of the Moon’s fossil bulge establishes that the presence of liquid water on Earth previous to 4 billion years ago indeed must have been limited to brief episodes in small geographical regions. That is, collision events during the Hadean era only would have melted Earth’s frozen water for a brief time near the sites of the collisions. In other words, Earth was not as heavily bombarded during the Hadean era as planetary astronomers once thought. Figure 3 shows a revised history of collision events throughout Earth’s history that is consistent with both the new model for the formation of the Moon’s fossil bulge and with the Sun being much fainter during the Hadean era (see figure 1).
Figure 3: New Bombardment Model of Earth throughout Its Early History. The spike at 3.9 billion years ago represents the late heavy bombardment. Collision rate for the 400 million years previous to the late heavy bombardment would have been inadequate to prevent the formation of nearly ubiquitous surface ice.
image credit: Hugh Ross
What the New Evidence Means
An obvious implication of the new model for the formation of the Moon’s fossil bulge is that Earth scientists will need to rename the Hadean era. Earth from 4.4–4.0 billion years ago was not hellishly hot. It was freezing cold. The Hadean era really was the Cryo era. (The name Cryogenian already is taken for the Sturtian and Marinoan glaciations that occurred 720–635 million years ago.)
Another obvious implication of the new lunar fossil bulge model is that it provides yet another clear-cut refutation of young-earth creationism. The model establishes not only that the fossil bulge must have formed more than 3 billion years ago but that the formation of the bulge needed at least 300 million years to form.
A much more significant implication of the new lunar fossil bulge model concerns the origin of life. Neither the frozen state of Earth during the Cryo era nor the brief local incidents of heat from collision events are conducive to either the origin or survival of life. Therefore, the evidence for the rapid appearance of life 3.825 billion years ago immediately after the late heavy bombardment (see figures 2 and 3) argues that life’s origin was a supernatural event.4 In addition to what I have already presented in chapter 8 of Improbable Planet,5 the new lunar fossil bulge model provides yet more evidence that God, not unguided natural processes, was responsible for life’s origin.