Fluffy dust grains from comet 67P/Churyumov-Gerasimenko

Fluffy dust grains gathered by the ESA Rosetta spacecraft COSIMA instrument from comet 67P/Churyumov-Gerasimenko between October 25 -31, 2014 when the comet was between 3.113 and 3.074 AU from the sun and before the comet was predicted to shed its dusty mantle. Dust particle "a" on the left crumbled into a rubble pile when collected. Dust particle "b" on the right shattered. Each particle is shown with two illumination views which project different shadow lengths becuase of their size.

During the comet's 2008 return, the comet's dust production doubled when it was between 2.7 and 2.5 AU from the Sun (July 2008), indicating that this was when the nucleus shed its mantle. The authors of a paper in Nature publised on in Feb 2015 suggests that these particles are agglomerates of entities in the size range of interplanetary dust particles and probably represent parent material of interplanetary dust particles.

Reference:
Schulz, Rita; Hilchenbach, Martin; Langevin, Yves; Kissel, Jochen; Silen, Johan; Briois, Christelle; Engrand, Cecile; Hornung, Klaus; Baklouti, Donia; Bardyn, Anaïs; Cottin, Hervé; Fischer, Henning; Fray, Nicolas; Godard, Marie; Lehto, Harry; Le Roy, Léna; Merouane, Sihane; Orthous-Daunay, François-Régis; Paquette, John; Rynö, Jouni; Siljeström, Sandra; Stenzel, Oliver; Thirkell, Laurent; Varmuza, Kurt; Zaprudin, Boris, Comet 67P/Churyumov-Gerasimenko sheds dust coat accumulated over the past four years (02/2015), Nature, Volume 518, Issue 7538, pp. 216-218
http://adsabs.harvard.edu/abs/2015Natur.518..216S

Image credit: ESA/Rosetta/MPS for COSIMA Team MPS / CSNSM / UNIBW / TUORLA / IWF/ IAS / ESA BUW / MPE / LPC2E / LCM / FMI / UTU / LISA / UOFC / vH&S
http://www.esa.int/spaceinimages/Images/2015/01/Fluffy_dust_grains