An Archaean heavy bombardment from a destabilized extension of the asteroid belt

  title={An Archaean heavy bombardment from a destabilized extension of the asteroid belt},
  author={William F. Bottke and David Vokrouhlick{\'y} and David A. Minton and David Nesvorn{\'y} and Alessandro Morbidelli and Ramon Brasser and Bruce M. Simonson and Harold F. Levison},
The barrage of comets and asteroids that produced many young lunar basins (craters over 300 kilometres in diameter) has frequently been called the Late Heavy Bombardment (LHB). Many assume the LHB ended about 3.7 to 3.8 billion years (Gyr) ago with the formation of Orientale basin. Evidence for LHB-sized blasts on Earth, however, extend into the Archaean and early Proterozoic eons, in the form of impact spherule beds: globally distributed ejecta layers created by Chicxulub-sized or larger… 

The Late Heavy Bombardment

Heavily cratered surfaces on the Moon, Mars, and Mercury show that the terrestrial planets were battered by an intense bombardment during their first billion years or more, but the timing, sources,

Effects of early intense bombardment on megaregolith evolution and on lunar (and planetary) surface samples

Impact rates in the first 500 Myr of the solar system are critical to an understanding of lunar geological history, but they have been controversial. The widely accepted, post‐Apollo paradigm of

Early Impact History and Dynamical Origin of Differentiated Meteorites and Asteroids

Laboratory studies of igneously formed meteorites suggest that numerous meteorite parent bodies were melted to form metallic cores and silicate mantles. Studies by the Dawn spacecraft confirm that

A sawtooth-like timeline for the first billion years of lunar bombardment

The timeline of the lunar bombardment: Revisited




Origin of the cataclysmic Late Heavy Bombardment period of the terrestrial planets

This model not only naturally explains the Late Heavy Bombardment, but also reproduces the observational constraints of the outer Solar System.

A Younger Age for ALH84001 and Its Geochemical Link to Shergottite Sources in Mars

The calculated Lu/Hf and Sm/Nd (samarium/neodymium) ratios of the ALH parental magma source indicate that it must have undergone extensive igneous processing associated with the crystallization of a deep magma ocean, suggesting uniform igneous processes in Mars for nearly 4 billion years.

Impact spherules as a record of an ancient heavy bombardment of Earth

Estimates of the sizes and impact velocities of the asteroids that created global spherule layers reveal that the impactor flux was significantly higher 3.5 billion years ago than it is now, consistent with a gradual decline of theimpactor flux after the Late Heavy Bombardment.

Cataclysmic bombardment throughout the inner solar system 3.9–4.0 Ga

[1] Cohen et al. [2000] recently confirmed the hypothesis that the Moon was resurfaced by an intense period of impact cratering ∼3.9 Ga ago and, by inference, that the Earth also sustained

39Ar‐40Ar dating of the Zagami Martian shergottite and implications for magma origin of excess 40Ar

Abstract— The Zagami shergottite experienced a complex, petrogenetic formation history (McCoy et al. 1992, 1999). Like several shergottites, Zagami contains excess 40Ar relative to its formation age.


▪ Abstract A large extraterrestrial object striking Earth at cosmic velocity melts and vaporizes silicate materials, which can condense into highly spheroidal, sand-size particles that get deposited