New Light on Young Stars:
Spitzer's View of Circumstellar Disks

The Historical Distribution of Zodiacal Dust Levels and the Detection of Exo-Earths

First Author:
Marc Kuchner
Email: Marc.Kuchner AT nasa.gov
NASA Goddard Space Flight Center
Greenbelt, MD 20771 USA

Abstract

Seafloor sediment 3He concentrations trace the flux of interplanetary dust onto the Earth. We compile existing data on these concentrations from ~80 Myr ago to the present and examine the implications of this data for missions like the Terrestrial Planet Finder (TPF) that aim to find habitable extrasolar Earth-like planets. We find that the dust levels have a log normal distribution, implying that 95% of solar analogs should have zodiacal dust concentrations in the range of 0.6--2.6 zodis, to the extent that these stars have asteroid belts similar to our own in terms of collision statistics. Our results can serve as a null hypothesis for future surveys of exozodiacal dust and provide minimum requirements for planning TPF.