Purpose/Background of this experiment:

Planetary aerosol particles are formed in the upper atmospheric regions through photochemical/electron collision reactions with various gases. The complex molecules formed descend downwards, coagulate, and condense in the lower temperatures of troposphere. In Titan, the largest satellite of Saturn, which will be a focus of Cassini mission observations, a significant amount of infrared opacity is attributed to atmospheric aerosol particles. The nature of the composition of the aerosol/cloud particles, and super-saturation and condensation processes remains unclear and is source of considerable uncertainty in interpretation of the observations. Laboratory investigations of these processes may thus resolve many issues.

Titan's Thick Haze Layer (NASA/JPL)

Titan's Cloud System (NASA/JPL)

Cassini (NASA/JPL)

Approach:

The same experimental technique used to study dust charging mechanisms will be used for this investigation. Single dust grains of interplanetary and interstellar composition and physical types will be used. The experiment includes:

• The test cavity evacuted to low pressures,
• Cryogenic facililty employed for cooling a suspended nucleus dust grain to astrophysical temperatures,
• Experiment carried out by injecting a volatile gas into the cavity and measuring the particle mass as a function of pressure.