ISSN:
1573-0794
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Notes:
Abstract When Oort cloud comets enter the planetary region their orbital evolution is dominated by encounters with the planets. Some of them become short period comets and enter the terrestrial planetary region to form a potential source of cratering. We have computed the orbital evolution of comets by encounters with the seven major planets. We find 0.5–2 impacts/Myr on the Earth, somewhat lower than the observed rate of about 2.8 impacts per Myr causing craters ≥ 20 km in diameter. Thus as far as numbers go, it is quite possible that dead comets are a major, even if not the dominant source of cratering on the Earth. We have also tested how well the expected variations in the Oort cloud comet flux show up in the rate of impacts. We find that the periodicity is reflected also in the cratering rate, though with a time delay and with added noise.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00612962
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