Cold ionospheric plasma in Titan's magnetotail

Abstract

The interaction between Titan and the corotating Saturnian plasma forms an induced magnetosphere with an elongated Alfven‐wing‐style magnetotail. On 26 December 2005, the Cassini spacecraft flew through Titan's magnetotail, providing the first distant tail observation, over 5 Titan radii downstream. We examine measurements observed by the magnetometer and Langmuir probe during this pass. We use the direction of the magnetic field along the trajectory to identify the source regions of plasma reaching the spacecraft. Cold plasma, with a density of about 10 cm−3, is found magnetically connected to the ionosphere. Titan's ionosphere appears to be escaping along field lines down the tail, leading to particle loss from the atmosphere.