The mention of comet orbits being disturbed by planetary gravity points to the error in the use of comets for dating. Short-period comets are comets that have been moved into short period orbits by gravitational interactions. The constant discovery of previously unseen comets reflects the continuous supply of nearby comets due to gravitational disturbance of very long period objects, in addition to occasionally happening to spot something that no one noticed before. Part of this supply of potential comets lies in the Kuiper belt. Here several objects have been observed which, if gravity changed their orbit appropriately, could become short or medium period comets.
Claiming that a comet in the inner solar system proves that the solar system is young is analogous to my finding an ice cube in my cup and concluding that the cup was created more recently than the time for the ice to melt. The comets are older, but they have ony been in the inner solar system a short time.
Meteor showers represent the remains of older comets. Probably many stray meteors derive from even older comets, now disintegrated. Large numbers of comets crash into the Sun every year as well-a solar observatory satellite has discovered over 100 hits and near misses. Thus, there is evidence of constant attrition of comets as well.
Dr. David Campbell
"Old Seashells"
Biology Department
Saint Mary's College of Maryland
18952 E. Fisher Road
St. Mary's City, MD 20686-3001 USA
dcampbell@osprey.smcm.edu, 301 862-0372 Fax: 301 862-0996
"Mollusks murmured 'Morning!'. And salmon chanted 'Evening!'."-Frank Muir, Oh My Word!
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