A Meteoroid "super–volcanism" on the Earth and Mars in the Hadean

Introduction: Meteoroids with sizes ~100–200 µm represent the dominant mass fraction of the extraterrestrial material accreted by the Earth. Those that survive unmelted upon atmospheric entry can be recovered as micrometeorites in Antarctica ices and snows (AMMs). Their analysis show that ~99% of the meteoroids are related to the most volatile– rich meteorites, the hydrous carbonaceous chondrites, and dominantly to the CM chondrites. Upon atmospheric entry, each meteoroid produces a radar shooting star and a tiny "puff" of gases and smoke particles that feed a meteoroid "volcanism", rooted around the thermopause. The meteoroid origin of the Earth's atmosphere was already discussed [1, 2, 3]. In this abstract, we first outline the computation of the total amount of any meteoroid species accreted by the young Earth and Mars, since the merging of their last planetary embryo, at time, t 1. These computations are next exploited to decrypt the Hadean meteoroid sulfur cycle on both planets and its effects on their climates. In a companion abstract [4], we turn to Spirit and Opportunity to better constraint the origin of the thin contemporary Martian atmosphere. A meteoroid accretion equation: Earth: The self–erasing mega–impact by the last planetary embryo (about 10 lunar mass) did form the Moon at time, t 1 , which corresponds to the formation age of the oldest lunar highland rocks (~4.44 Ga). It also simultaneously closed the formation time interval of the Earth and blew off its intractable pre-lunar atmosphere. Next, during the first ~100–200 Ma of the post-lunar period, meteoroids generated a new atmosphere. Their mass input rate was exponentially decaying with time, accordingly to the dimensionless relative lunar cratering rates, K(t), conjectured by Hartmann and subsequently improved by Neukum [5]. Indeed, one could expect that both the lunar impactors and the parent bodies of meteoroids were dominantly extracted from the same reservoirs of bodies. If the impactor number mass flux is K(t)x higher than today, the meteoroid mass flux will be multiplied by the same factor (cf. Ref. 6, p. 273). In particular, the total amount, M A , of a given meteoroid species, A, delivered to the Earth scales as: M A ~[A(wt. %) x 10