[ckissick]

Since Venus is inside earth's orbit, we only see it at full phase, like a full moon, when it's farthest away from earth. Since brightness is proportional to the square of the distance, and the distances are so great, it's not very bright when it's in its full phase. It turns out that it's at its brightest when we can see only 26% of it, because it's very close at that time. In fact, at its brightest, it's 4.16 times brighter than when it's full. Right now it's at about 1/2 phase.