Dr. Robert Whitten

With the thickest air of any moon in the solar system, Titan sports an atmosphere that, among other things, may produce rain showers of liquid natural gas. Atmosphere scientist Bob Whitten leads a research effort to investigate another peculiar effect on this Saturnian satellite: how cosmic rays interact with the smog in Titan’s air. In particular, he’s interested in learning how the electrical conductivity of this alien atmosphere depends on these incoming, high-energy particles, on haze, and on sunlight.

While Titan is interesting in its own right, understanding the physics of its atmosphere might also provide clues to the conditions of early Earth’s own gaseous mantle. This cold, far-off moon, so seemingly unlike our own planet, may be a crystal ball offering insight into Earth’s very distant past.

Projects

“Electrification of the Clouds of Planets”

NNA04CC64A

The charging of aerosol particles in planetary atmospheres is important in that free electrons produced by galactic cosmic rays (GCR) and (at high altitudes) by electrons precipitating from magnetospheres (if present) attach to the particles; this process can lead to the occurrence of lightning and the production of complex molecules of significance to the origins of life. Similar arguments concerning the occurrence of lightning on the dayside, where the particles are positively charged, also hold true. An earlier study (Borucki et al, 1987) using a much less sophisticated model led to preliminary results for the night side of Titan. A much more sophisticated model that simulates such effects has been developed and has yielded preliminary results for both the dayside and night side of Titan. Models are being investigated for Jupiter and Mars and well as for Titan.