After four years of data analysis, with four million personal computers on the job, SETI@home takes over the Arecibo radio telescope this week. Chief scientist Dan Werthimer talks about aiming the great dish at the top one hundred and fifty star systems. Will he find evidence of extraterrestrial intelligence?
Emily Lakdawalla talks about just how far a SETI search can reach, and Bruce Betts returns with What's Up? and a new trivia question.