AAO Colloquium. Tuesday, 10 July - 3:30pm AAO Conference Room Understanding our Twisted Sister: Near-IR Remote-Sensing Observations of the Venus Atmosphere. Dr Vikki Meadows Jet Propulsion Laboratory, NASA Although considered to be the Earth's closest "twin" in the solar system, the nature of the surface and atmosphere of the planet Venus has been difficult to study due to the planetwide sulfuric-acid cloud deck, and the extremely hostile surface conditions. However, with the discovery in the early 90s of atmospheric "windows" in the near-infrared spectrum of the planet, it has been possible to probe the surface and lower atmosphere of Venus from the relative comfort of our own ground-based telescope facilities. This talk provides an overview of the remote-sensing techniques currently being used by ground-based Venus observers and planned for several Venus spacecraft mission concepts, and describes the latest and most significant insights into the nature of the Venus atmosphere that we have obtained using these new techniques.