Neutral Atom Imaging of Solar Wind Interaction With Venus  

Mei-Ching Fok, Thomas E. Moore, and Takahashi Tanaka


Observations from the Low Energy Neutral Atom (LENA) imager on the Imager for
Magnetopause-to-Aurora Global Exploration (IMAGE) mission have emerged as a
promising new tool for studying the solar wind interaction with the terrestrial
magnetosphere. Strong LENA emissions were seen during magnetic storms,
especially during high solar wind dynamic pressure when the magnetopause was
strongly compressed and the magnetosheath could interpenetrate the outer
geocorona. Venus, unlike the Earth, has no intrinsic magnetic field so the solar
wind penetrates deeply and interacts directly with its upper atmosphere. The
processes of interaction enhances atomic escape and thus plays a potentially
important role in the evolution of the atmosphere. We have performed LENA
simulations of the solar wind interaction with Venus. LENA emissions from the
planet are calculated based on a global MHD model of Tanaka. Preliminary
analysis shows that the simulated ENA emissions are greater than for the Earth,
and quite suitable to probe the Venus plasma environment and its interaction
with the solar wind. This simulation work demonstrates the feasibility of
remotely sensing the Venusian solar wind interaction and resultant atmospheric
escape using fast neutral atom imaging.

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Presentation, 2nd Annual Asia Oceanic Geosciences Society Meeting, Singapore 
20-24 June 2005