The first 150 million years of solar system history witnessed the formation of the rocky and gas giant planets, the Earth's Moon, and the asteroid belt. We seek to define the absolute and relative timing of these events, particularly in the inner solar system in order to explore hypotheses for their nature, origins, and timing of events at 10^6 to 10^8 time scales. For example, iron meteorites ages span from CAI formation to Mars formation, whereas chondrites ages postdate most early, small planetesimal formation and differentiation. Rocky planets likely grew rapidly by accretion of differentiated planetesimals (e.g., iron meteorite parent bodies) heated by 26Al. In contrast, chondritic parent bodies that accreted post-26Al lifetime remained undifferentiated. Mars and the Earth are equally enriched in refractory elements at 1.9 times CI chondrite, Mars is less volatile-depleted and more oxidized, and both formed Hadean crusts in the presence of surface water (cf., the Moon). We welcome contributions providing insights from physics and chemistry to the mechanisms forming and influencing these processes.

The first 150 million years of solar system history witnessed the formation of the rocky and gas giant planets, the Earth's Moon, and the asteroid belt. We seek to define the absolute and relative timing of these events, particularly in the inner solar system in order to explore hypotheses for their nature, origins, and timing of events at 10^6 to 10^8 time scales. For example, iron meteorites ages span from CAI formation to Mars formation, whereas chondrites ages postdate most early, small planetesimal formation and differentiation. Rocky planets likely grew rapidly by accretion of differentiated planetesimals (e.g., iron meteorite parent bodies) heated by 26Al. In contrast, chondritic parent bodies that accreted post-26Al lifetime remained undifferentiated. Mars and the Earth are equally enriched in refractory elements at 1.9 times CI chondrite, Mars is less volatile-depleted and more oxidized, and both formed Hadean crusts in the presence of surface water (cf., the Moon). We welcome contributions providing insights from physics and chemistry to the mechanisms forming and influencing these processes.