Using the Hubble, astronomers watched 47-Tucanae for eight days hoping to discover giant planets passing in front of their stars. They expected to see at least 17 such eclipses, and maybe as many as 40. But, even with 34,000 stars to monitor at one time, they didn't see a single planet! The gravity or radiation of clusters must make it difficult for large planets to form. This is one of the series of images taken for this project.
Credit: NASA/Ron Gilliland (STScI)