Cometary dust: A thermal criterion to identify cometary samples among the interplanetary dust collected from the stratosphere Available to Purchase

The interplanetary dust particles collected from the Earth’s stratosphere are believed to sample both the asteroids and the comets. Near‐earth gravitational segregation favors collection of the lowest velocity interplanetary dust, from the main‐belt asteroids, enhancing its proportion in near‐earth collections over its proportion in space. Nonetheless, some cometary dust must be present on the stratospheric collectors. A thermal criterion has been developed to separate the interplanetary dust collected from the stratosphere into two groups: one heated more extremely than is possible for main‐belt asteroidal particles, and a second heated less extremely. The first group should consist of cometary particles, while the second group should include both main‐belt asteroidal particles and cometary particles which encountered the Earth under favorable entry conditions.