Hot Flow Anomalies at Venus

We present a multi-instrument study of a Hot Flow Anomaly (HFA) observed by the Venus Express spacecraft in the Venutian foreshock, expanding on an initial study by Slavin et al [2009] that employed magnetometer observations of an HFA-like event during the flyby of NASA's Messenger spacecraft. Whilst the Messenger events were indicative of an HFA, they were unable to demonstrate the unambiguous signatures of plasma heating or deflection due to the paucity of data. We examine the complex internal structure of a Venutian HFA on the 22nd of March 2008, incorporating both Venus Express magnetometer and ASPERA plasma observations to demonstrate the presence of plasma heating within one such event. Centered on an interplanetary discontinuity and bounded by shock, the properties of this event are consistent with those of HFA's observed at other planets within the Solar System. Finally, we present a discussion of the implications of an HFA on the planet Venus.