Posted by
ValiantForTruth on Wednesday, May 23, 2007 7:46:17 PM
Comets and a Young Solar System
A typical comet, when far from the Sun, resembles a dirty, misshapen snowball, a few miles across. About 38% of its mass 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. They even contain organic matter which many early scientists concluded came from ‘decomposed organic bodies.’ Today, a popular belief is that comets brought life to Earth. Instead, comets may have traces of life from Earth.
As a comet approaches the Sun, a small fraction of the snowball evaporates, forming a gas and dust cloud. Solar wind pushes comet tails away from the Sun, so comets traveling away from the Sun move tail-first.
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 receive gravity boosts that fling them, like a slingshot, out of the solar system forever. Since comets are fragile, they are sometimes torn apart as shown in Figure 1.
FIGURE 1 - Death of Comet Shoemaker-Levy 9
Jupiter’s Family of Comets
Of the almost 1,000 known comets, 205 orbit the Sun in less than 100 years. These are the short-period comets. About 60% of all short-period comets have aphelions 4–6 AU from the Sun. A comet obits the sun in an elliptical path. The aphelion is its farthest point from the Sun. An AU is a unit of measure equal to the nominal distance between the sun and earth. So, the earth is 1 AU from the sun. Because Jupiter travels in a nearly circular orbit that lies near the center of that range (5.2 AU from the Sun), those comets are called Jupiter’s family as shown in Figure 2. Comets in Jupiter’s family do not travel with Jupiter, but they share the orbital characteristic of aphelion distance.
What does this observation have to say about the origin of comets? Why should comets cluster into families defined by aphelions? Why is Jupiter’s family so large? No doubt, Jupiter’s gigantic size has something to do with it.

FIGURE 2 - Jupiter's Family of Comets
Collection of Jupiter's Family
How Jupiter collected its large family of comets presents major problems, because comets falling toward the Sun from the outer solar system would be traveling too fast as they zip inside Jupiter’s orbit. To slow them down so they could join Jupiter’s family would require such great deceleration forces that the comets would have to pass very near planets. But those near passes could easily tear comets apart or eject them from the solar system.
To better understand what is meant by ‘Jupiter’s family,’ refer to Figure 3. While comets A, B, and C orbit the Sun, only A and B are in Jupiter’s family, because their farthest point from the Sun is near Jupiter’s orbit.
FIGURE 3 - Short period comets associated with Jupiter’s orbit
A bullet, when fired straight up, slows to almost zero velocity near the top of its trajectory; its farthest point from Earth. A comet also moves very slowly near its aphelion. If a comet’s aphelion is ever near Jupiter during any orbit, Jupiter’s large gravity will pull the nearly stationary comet steadily toward Jupiter. Because a comet spends a relatively long time near its farthest point, Jupiter’s gravity acts for an equally long time. Even a comet’s orbital plane is slowly but steadily aligned with Jupiter’s. Thus, aphelions of short-period comets tend to be pulled toward Jupiter’s nearly circular orbit, regardless of whether the aphelion is inside, outside, above, or below that circle.
One can think of Jupiter’s mass as being spread out in a hoop that coincides with Jupiter’s orbit. This “hoop analogy” simplifies the analysis of many long-term gravitational effects. Comets feel more pull toward the nearest part of the hoop.
Statistical examination of all historical sightings of every orbit (almost 500) of every comet in Jupiter’s family confirms this effect.
Comets in Jupiter’s family run an increased risk of colliding with Jupiter or planets in the inner solar system, or being expelled from the solar system by Jupiter’s gigantic gravity. Therefore, they have a life expectancy of only about 12,000 years.
What are the possibilities? (1) Jupiter’s family of comets are young measured in thousands of years, (2) the family is resupplied rapidly by unknown processes.
Conclusion
Could we not conclude that comets originated recently from the inner solar system in order to join Jupiter’s family, since such comets could not have come from beyond Jupiter’s orbit? What would prevent us from making that conclusion? Our view of the Genesis Flood is not at all catastrophic enough. Even though the Lord compares his coming to the Days of Noah and one comparison that could be made is the level of destruction that occurs on the earth and its effects on the heavens, our view of the Genesis Flood is not at all catastrophic enough.
Credits to Dr. Walt Brown for his free, online book at www.creationscience.com. He has the most comprehensive view of flood related phenomenon to our knowledge. This material is taken from his chapter on the origin of comets.
We introduce it here to illustrate how prevailing theory can restrict the advancement of science by making accommodations to anomalous data rather than reexamining the theory. The Oort cloud is an imaginary source of comets to replenish the comet supply, since it is generally agreed that comets have limited life expectancies of around 12000 years.
Only if we are not bound by the long ages of evolution theory, can we conclude that comets formed within that time period. Dr. Brown’s hydroplate theory gives a good explanation for the origin of comets. It also addresses the flood related language of Genesis 7:11 and 8:2: ‘the fountains of the great deep were broken’ and ‘the windows of heaven were opened.’
The hydroplate theory places the source of comets at Earth, well inside Jupiter’s orbit. Therefore, many comets reach their slowest speeds within a few astronomical units of Jupiter’s hoop. Thousands of years of gentle gravitational tugs by this hoop have gathered Jupiter’s family. Although Jupiter sometimes destroys comets or ejects them from the solar system, many comets in its family remain, because they were recently launched.