At http://phys.org/print392535290.html … the Rosetta mission's dust analysing instrument has found carbon in a more complex from than expected, according to a paper in Nature (Sept 8th 2016). The dust of comet Churyumov-Gerasimenko has come up trumps it would seem as previously, organic material was found in gases sublimated from the comet (in the coma) but now we have the presence of carbon mixed with other elements such as sodium, magnesium, aluminium, silicon, calcium, and iron. These are held together in large macromolecules compounds. Lots of hydrogen is present in the comet dust as well and the authors of the study have compared the elements with those found in meteorities that have landed on earth.
At http://phys.org/print392449778.html … astronomers have studied a succession of outbursts from comet 15P/Finlay in 2014 and 2015 (see also http://arxiv.org/abs/1609.00792) and compared them with those of Comet Holmes (2007) and another one from 2010 and suggest a role for the solar wind (as the comets approached and rounded the sun). They go on to say such behaviour is common to the Jupiter family of comets and also to Encke type comets – with a propensity to dissipate dust particles into near space.