Beschreibung:
<jats:p>
Numerical modeling of the orbital evolution of interplanetary dust particles revealed that, over the past 1.2 million years, the rate of accretion of dust by Earth has varied by a factor of 2 to 3. These variations display a 100,000-year periodicity and are anticorrelated with Earth's changing orbital eccentricity. Extraterrestrial helium-3 concentrations in a deep-sea sediment core display a similar periodicity but are 50,000 years out of phase with the predicted variations. Also, because collisions between large bodies in the asteroid belt are inevitable, it is expected that large-amplitude stochastic variations on 10
<jats:sup>7</jats:sup>
- to 10
<jats:sup>8</jats:sup>
-year time scales would be superimposed on the 10
<jats:sup>5</jats:sup>
-year periodic variations.
</jats:p>