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Updated: Jul 12, 2026
11:34
Scattering And Absorption of Light in Planetary Regoliths
Published on: July 1, 2019
Geological rhythms and cometary impacts
Science (New York, N.Y.)
|December 21, 1984
Summary
Periodic comet impacts, occurring every 33 and 260 million years, correlate with geological and biological upheavals. These cycles suggest extraterrestrial influences on Earth's evolution and tectonism.
Area of Science:
- Geology
- Paleontology
- Astronomy
Background:
- The Phanerozoic Eon is marked by significant geological and biological events.
- Understanding long-term cycles in Earth's history is crucial for evolutionary and geological studies.
Purpose of the Study:
- To identify and analyze periodicities in geological and biological upheavals during the Phanerozoic Eon.
- To investigate the potential link between these periodicities and extraterrestrial phenomena, specifically comet impacts.
Main Methods:
- Time-series analysis of geological and biological upheaval data from the Phanerozoic Eon.
- Comparison of identified periodicities with the cycles of impact cratering on Earth.
Main Results:
- Two dominant, stable long-term periodicities were identified: approximately 33 +/- 3 million years and 260 +/- 25 million years.
- These cycles closely match the periods and phases of Earth's impact cratering record.
- The findings suggest a strong correlation between periodic comet impacts and global tectonism and biological evolution.
Conclusions:
- Periodic comet impacts are a significant factor influencing Earth's geological and biological history.
- The observed 33 and 260-million-year cycles may originate from the solar system's interactions with interstellar clouds during its galactic orbit.
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