This is the online edition of In the Beginning: Compelling Evidence for Creation and the Flood
(7th Edition) by Dr. Walt Brown. The online version of the book is designed to be read online.
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The Origin of Comets
SUMMARY: Past explanations for how comets began have serious problems. After a review of some facts concerning comets, a new explanation for comet origins will be proposed and tested. It appears that the fountains of the great deep and the power of expanding, high-pressure, supercritical water exploding into the vacuum of space launched comets into the solar system as the flood began. Other known forces would have assembled the expelled rocks and muddy droplets into larger bodies resembling comets in size, number, density, composition, spin, texture, strength, chemistry (organic and inorganic), and orbital characteristics. After a comparison of theories with evidence, problems with the previous explanations will become apparent.
Figure 141: Arizona’s Meteor Crater. Comets are not meteors. Comets are like giant, dirty, exceedingly fluffy “snowballs.” Meteors are rock fragments, usually dust particles, falling through the atmosphere. “Falling stars” streaking through the sky at night are often dust particles thrown off by comets years ago. In fact, every day we walk on comet dust. House-size meteors have formed huge craters on Earth, the Moon, and elsewhere. Meteors that strike the ground are renamed “meteorites,” so the above crater, 3/4 mile wide, should be called a “meteorite” crater.
On the morning of 14 December 1807, a huge fireball flashed across the southwestern Connecticut sky. Two Yale professors quickly recovered 330 pounds of meteorites, one weighing 200 pounds. When President Thomas Jefferson heard their report, he allegedly said, “It is easier to believe that two Yankee professors would lie than that stones would fall from heaven.” Jefferson was mistaken, but his intuition was no worse than ours would have been in his time. Today, many would say, “The Moon’s craters show that it must be billions of years old” and “What goes up must come down.” Are these simply mistakes common in our time?
As you read this chapter, test such intuitive ideas and alternate explanations against evidence and physical laws. Consider the explosive and sustained power of the fountains of the great deep. You may also surmise why the Moon is peppered with craters, as if someone had fired large buckshot at it. Question: Are comets “out of this world”?
Comets may be the most dynamic, spectacular, variable, and mysterious bodies in the solar system. They even contain organic matter,1 which many early scientists concluded came from “decomposed organic bodies.”2 Today, a popular belief is that comets brought life to Earth. Instead, comets may have traces of life from Earth.3
Comets orbit the Sun. When closest to the Sun, some comets travel more than 350 miles per second. Others, at their farthest point from the Sun, spend years traveling less than 15 miles per hour. A few comets travel so fast they will escape the solar system. Even fast comets, because of their great distance from Earth, appear to “hang” in the night sky, almost as stationary as the stars. Comets reflect sunlight and fluoresce (glow). They are brightest near the Sun and sometimes visible in daylight.
A typical comet, when far from the Sun, resembles a dirty, misshapen snowball, a few miles across. About 38% of its mass4 is frozen water—but this ice is extremely light and fluffy, with much empty space between ice particles. The rest is dust and various chemicals. As a comet approaches the Sun, a small fraction of the snowball (or nucleus) evaporates, forming a gas and dust cloud, called a coma, around the nucleus. The cloud and nucleus together are called the head. The head’s volume can be larger than a million Earths. Comet tails are sometimes more than an astronomical unit (AU) in length (93,000,000 miles), the Earth-Sun distance. One tail was 3.4 AU long—enough to stretch around Earth 12,500 times.5 Solar wind pushes comet tails away from the Sun, so comets traveling away from the Sun move tail-first.
Figure 142: Nucleus of Halley’s Comet. When this most famous of all comets last swung by the Sun in 1986, five spacecraft approached it. From a distance of a few hundred miles, Giotto, a European Space Agency spacecraft, took six pictures of Halley’s black, 9 x 5 x 5 mile, potato-shaped nucleus. This first composite picture of a comet’s nucleus showed 12–15 jets venting gas at up to 30 tons per second. (Venting and tail formation occur only when a comet is near the Sun.) The gas moved away from the nucleus at almost a mile per second to become part of the comet’s head and tail. Seconds after these detailed pictures were taken, Giotto slammed into the gas, destroying the spacecraft’s cameras.
Comet tails are extremely tenuous—giant volumes of practically nothing. Stars are sometimes observed through comet heads and tails; comet shadows on Earth, even when expected, have never been seen. One hundred cubic miles of comet Halley’s tail contains much less matter than in a cubic inch of air we breathe—and is even less dense than the best laboratory vacuum.
In 1998, a spacecraft orbiting the Moon detected billions of tons of water ice mixed with the soil in deep craters near the Moon’s poles. As one writer visualized it,
Comets raining from the sky left pockets of frozen water at the north and south poles of the moon, billions of tons more than previously believed, Los Alamos National Laboratory researchers have found.6
Comets are a likely source, but this raises perplexing questions. Ice should evaporate from almost everywhere on the Moon faster than comets currently deposit it, so why does so much ice remain?7 Also, ice seems to have been discovered in permanently shadowed craters on Mercury,8 the closest planet to the Sun. Ice that near the Sun is even more difficult to explain.
Fear of comets as omens of death existed in most ancient cultures.9 Indeed, comets were called “disasters,” which in Greek means “evil” (dis) “star” (aster). Why fear comets and not other more surprising celestial events, such as eclipses, supernovas, or meteor showers? When Halley’s comet appeared in 1910, some people worldwide panicked; a few even committed suicide. In Texas, police arrested men selling “comet-protection” pills. Rioters then freed the salesmen. Elsewhere, people quit jobs or locked themselves in their homes as the comet approached.
Comets are rapidly disappearing. Some of their mass is “burned off” each time they pass near the Sun, and they frequently collide with planets, moons, and the Sun. Comets passing near large planets often are torn apart or receive gravity boosts that fling them, like a slingshot, out of the solar system forever. Because we have seen so many comets die, we naturally wonder, “How were they born?”
Textbooks and the media confidently explain, in vague terms, how comets began. Although comet experts worldwide know those explanations lack details and are riddled with scientific problems, most experts view the problems, which few others appreciate, as “future research projects.”
To learn the probable origin of comets, we should:
a. Understand these problems. (This will require learning how gravity moves things in space, often in surprising ways.)
b. Learn a few technical terms related to comets, their orbits, and their composition.
c. Understand and test seven major theories for comet origins.
Only then will we be equipped to decide which theory best explains the origin of comets.