Task: Text Simplification
Input (English): The science of geochronology is the prime tool used in the discipline of chronostratigraphy , which attempts to derive absolute age dates for all fossil assemblages and determine the geologic history of the Earth and extraterrestrial bodies .
Output (English): Geochronology is the main tool used to get absolute age dates for all fossil assemblages , and for the history of the Earth and other bodies .