523: Judging Age & Origins, Pt. 2 Across the Solar System Astronomy Cast 523: Judging Age & Origins, Pt. 2 Across the Solar System by Fraser Cain & Dr. Pamela Gay Today we push our aging curiosity out into the Solar System to ask that simple question: how old is it and how do we know? What techniques do astronomers use to age various objects and regions in the Solar System? This is part two of a series.