It's hard to create realistic mathematical models of galaxies. They come out wrong even after lots of work. But now there's one that come closer to reality, partly thanks to inclusion of stellar nurseries and dark matter. Young astrophysicist Javiera Guedes tells us how it was done. Bill Nye sees the good, the bad and the ugly in the latest NASA budget decisions. Emily Lakdawalla celebrates the miraculous return and analysis of asteroid dust by the Hayabusa probe. Bruce Betts dons his new Star Wars t-shirt for another What's Up segment with Mat Kaplan, including a new space trivia contest for listeners.