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The habitability of planets is strongly affected by impacts from comets and asteroids. Indications from the ages of Moon rocks suggest that the inner Solar System experienced an increased rate of impacts roughly 3.8 Gya known as the Late Heavy Bombardment (LHB). Here we develop a model of how the Solar System would have appeared to a distant observer during its history based on the Nice model of Gomes et al. (2005). We compare our results with observed debris discs. We show that the Solar System would have been amongst the brightest of these systems before the LHB. Comparison with the statistics of debris disc evolution shows that such heavy bombardment events must be rare occurring around less than 12% of Sun-like stars.
We introduce a probabilistic approach to the problem of counting dwarf satellites around host galaxies in databases with limited redshift information. This technique is used to investigate the occurrence of satellites with luminosities similar to the
We utilize observations of 16 white dwarf stars to calculate and analyze the oxidation states of the parent bodies accreting onto the stars. Oxygen fugacity, a measure of overall oxidation state for rocks, is as important as pressure and temperature
The observed Galactic rate of stellar mergers or the initiation of common envelope phases brighter than M_V=-3 (M_I=-4) is of order 0.5 (0.3)/year with 90% confidence statistical uncertainties of 0.24-1.1 (0.14-0.65) and factor of 2 systematic uncert
The two closest Gamma-Ray Bursts so far detected (GRBs 980425 & 060218) were both under-luminous, spectrally soft, long duration bursts with smooth, single-peaked light curves. Only of the order of 100 GRBs have measured redshifts, and there are, for
The dust production in debris discs by grinding collisions of planetesimals requires their orbits to be stirred. However, stirring levels remain largely unconstrained, and consequently the stirring mechanisms as well. This work shows how the sharpnes