Planetary scientists are looking to asteroids as the source of Earth’s water – not from evidence, but from desperation.
The Bible’s book of Genesis describes Earth covered with water from its creation. Not so, say the secular evolutionists: Earth began as a hot, dry, rocky body spewing volcanoes and facing a bombardment of space debris. Problem: why is it covered with water today? Even though the oceans are a relatively thin veneer on the globe, making up about 1% of Earth’s mass, their prominence is one of the defining characteristics of our “water planet.”
There have been three suggestions to answer the “H2O Enigma” (see 3/26/2002): a lucky strike by a big wet planetesimal, condensation from the solar nebula, and comets. The first two hypotheses are pretty much defunct, leaving comets. But for the last several years, secular planetary scientists have doubted that comets brought the water (see 11/03/2009), primarily because the hydrogen-to-deuterium ratio in cometary ice differs substantially from Earth water. (Deuterium abundance is thought to increase with distance from the sun.) In addition, direct observation of comets by Stardust and Deep Impact have shattered theories about their origins (12/27/2007, 9/24/2008, 4/18/2011).
As Space.com reported recently, it’s unlikely scientists can retreat back to condensation from the local solar nebula. The so-called “snow line” in planet formation theory is now thought to be even farther out than previously believed. Earth started out dry. Volatiles like water had to come special delivery.
Taking all the difficulties into account, NASA’s Astrobiology Magazine considered one last option: asteroids. In ” Meteorites Most Likely Source of Earth’s Water,” NASA pointed to work by Carnegie Institute scientists who believe water-bearing carbonaceous chondrites, with their lower deuterium ratios, could have been the delivery vehicles. Because the deuterium ratio is lower, they might have formed in the asteroid belt. The last paragraph shows this is only a suggestion:
“Our results provide important new constraints for the origin of volatiles in the inner Solar System, including the Earth,” Alexander said. “And they have important implications for the current models of the formation and orbital evolution of the planets and smaller objects in our solar system.”
A constraint is not a theory any more than an implication is. Scientists generally frown on ad hoc explanations that rely on luck to fix a problem.
Did any of them think this through? How many asteroids would it take? Unlike comets, asteroids are mostly rock. It would seem to squeeze enough water out of the rocks of carbonaceous chondrites, they would have to coat the whole Earth with a veneer of them. That should be clearly detectable. Also, the timing is critical in their hypothesis. It would have to arrive after the volcanoes stopped burying the land in lava; what made the asteroids come in then? Furthermore, the asteroids had to be the right size. Too big, and they would have boiled away any oceans being formed. This theory is ad hoc all over the Earth.
There is nothing in science that demands a bottom-up explanation. Science should go with where the evidence leads: top-down (i.e., intelligent design) or otherwise, without a pre-selected bias. A theory that includes an eyewitness account should be given more credence than one that relies on inferences from the unobservable past (unobservable, that is, to humans). For these reasons, given the implausibilities of the secular account, the Genesis account can be called the most accurate scientific explanation of the origin of the Earth’s oceans. Peter is harsh on the latter day uniformitarian scoffers, claiming they willfully forget that the world was created with its water from the beginning (2 Peter 3:3–6). The scientific data did not demand their bottom-up, mindless view. it was a choice.