Abstract
Venus is the only planet or star that can be seen by the naked eye during the day. Following the method of Westheimer (1985) for representing a point source as a single pixel on a screen with a resolution of 120 pixels per degree, we can convert the magnitude of Venus and the sky luminance into a luminance contrast signal with a contrast of 1.43. Detection models calibrated to the Modelfest data predict that such a target is below threshold (Watson & Ahumada, 2005). Modifications are proposed to the models to keep Venus visible.
http://vision.arc.nasa.gov/personnel/al/papers/10osa/handout.pdf
Supported by NASA Space Human Factors Engineering and the U.S. Navy.