Fine-scale structure in cometary dust tails II: Further evidence for a solar wind influence on cometary dust dynamics from the analysis of striae in comet C/2011 L4 Pan-STARRS

Motion of Cometary Dust

On timescales of days to months, the motion of cometary dust is mainly affected by solar radiation pressure, which determines dust dynamics according to the particle-scattering crosssection. Within this scenario, the motion of the dust creates structures referred to as dust tails. Tail photometry, depending on the dust cross-section, allows us to infer from model runs the best available outputs...

Distribution of Retrograde Cometary Dust Particles in the Solar System

On the Fine Structure of Cometary Plasma Tails

It is argued that the small-scale structures observed close to the plasma tail axis of comets may be a consequence of well-known finite-resistivity instabilities in the cometary cross-tail current sheet. While the "tearing" mode instability, which causes a breakup of the layer along the current flow lines, may be responsible for the observed small condensation or "knots" near the axis, the" rip...

Organic matter in comets and cometary dust.

Comets are primitive conglomerates of the solar system containing a mixture of frozen gases, refractory grains, and carbonaceous particles rich in biogenic elements. The dramatic display of comets is mostly caused by a cloud of micrometer-sized dust particles that leave the comet nucleus when frozen gases sublimate as they approach the Sun. Analyses of cometary dust captured in the stratosphere...

Morphological Structure and Chemical Composition of Cometary Nuclei and Dust

The chemical composition of comet nuclei derived from current data on interstellar dust ingredients and comet dust and coma molecules are shown to be substantially consistent with each other in both refractory and volatile components. When limited by relative cosmic abundances the water in comet nuclei is constrained to be close to 30% by mass and the refractory to volatile ratio is close to 1:...