Analysis of factors contributing to bulbous capture tracks from cometary dust particles in Stardust aerogel collector

The capture of cometary dust grains in aerogel at the well defined impact velocity of 6.1 km/s resulted in the production of a range of impact cavity morphologies. These tracks range from the classical carrot shaped tracks (type A) seen in laboratory experiments with efractory-solid projectiles, to bulbous tracks with “turnip”-like properties and a stylus (type B), to bulbous stubby tracks (type C) [1,2]. These morphologies must reflect the underlying variati on in the structure and strength of cometary dust grains. The cap

ture of cometary dust grains also presents the possibility that the chemical content of projec- tiles, in the form of volatiles that are released during capture, also

contributed to bulbous track features and analyses of the terminal particles and track residues suggest that the volatile content of the projectiles, released preferentially during capture, would have contributed to the range of morphologies seen in the Stardust

cometary dust tracks. An additional contributor to track bulb production could come from par

ticle fragmentation during cap-ture and here we present a quantita tive analysis of the factors that contribute to the production of bulbous impact cavities in aerogel.