ScienceNow:
The orbits of Earth and other planets lie within a thick,
pancake-shaped cloud of dust whose faint emission of reflected
sunlight is called zodiacal light. The dust origin was first
proposed in 1684 by Nicolas Fatio de Duillier. Now, David
Nesvorny of Southwest Research Institute has explained where
the dust originates: from comets whose orbits take them no
closer to the Sun than Jupiter's orbit.
