Outstanding aeronomy problems at Venus

Of all the non-terrestrial ionospheres and thermospheres in our solar system those of Venus have been explored and studied the most. This is mainly because of the 14 year exploration of the well-instrumented Pioneer Venus spacecraft and the theoretical studies prompted by the resulting observational information. However, there are still a number of areas where there are important scientific questions that remain unanswered. These areas include:(i) cs of the thermosphere, ergy mechanisms/sources responsible for maintaining the elevated plasma temperatures in the ionosphere, w/aurora intensities and their sources, and om populations. Express is likely to help address some of the questions related to the areas listed under (i), (iii) and (iv) above.