A couple of months back, we had a thread going about using occluders to help find earth-sized planets. I thought it was an interesting thread. I just heard an interesting podcast from "Nature" magazine that covers this topic. It seems that there's an evaluation process underway to do something with the Webb space telescope when it launches. This scheme involved an occluding disk several meters in size at a distance of 20 kilometers or so from the scope. Rather than using a circular disk, the proposal uses a flower-shaped disk to keep the diffraction effects out of the way. The podcast is available at this URL: http://www.nature.com/nature/podcast/index.html Look for the July 6 podcast. This particular article is about 3/4 of the way through (although the entire file is interesting). Michael