  Tiny meteoroids entering the Earth's atmosphere and inducing meteor showers
have long been thought to originate partly from cometary dust. Together with
other dust particles, they form a huge cloud around the Sun, the zodiacal
cloud. From our previous studies of the zodiacal light, as well as other
independent methods (dynamical studies, infrared observations, data related to
Earth's environment), it is now established that a significant fraction of dust
particles entering the Earth's atmosphere comes from Jupiter-family comets
(JFCs). This paper relies on our understanding of key properties of the
zodiacal cloud and of comet 67P/Churyumov-Gerasimenko, extensively studied by
the Rosetta mission to a JFC. The interpretation, through numerical and
experimental simulations of zodiacal light local polarimetric phase curves, has
recently allowed us to establish that interplanetary dust is rich in absorbing
organics and consists of fluffy particles. The ground-truth provided by Rosetta
presently establishes that the cometary dust particles are rich in organic
compounds and consist of quite fluffy and irregular aggregates. Our aims are as
follows: (1) to make links, back in time, between peculiar micrometeorites,
tiny meteoroids, interplanetary dust particles, cometary dust particles, and
the early evolution of the Solar System, and (2) to show how detailed studies
of such meteoroids and of cometary dust particles can improve the
interpretation of observations of dust in protoplanetary and debris disks.
Future modeling of dust in such disks should favor irregular porous particles
instead of more conventional compact spherical particles.
