Both were thrilled about Knudsen's rhetoric and invited him to join a science team for a European probe to Mars. In one of these meetings, two people from JPL heard Knudsen talk about Mössbauer spectroscopy. Shortly after, they invited him to JPL to talk about Mössbauer spectroscopy in a future Mars mission. At that conference in California, Knudsen used the last five minutes and 45 seconds of his talk to present the idea of using an array of magnets with decreasing field strength as a sort of continuation on the magnetic experiment carried out on the Viking lander missions. This idea intrigued the conference and Knudsen was asked whom they should talk to implement such an experiment: Knudsen said that he would call Robert B. Hargraves, who had been Principal Investigator in the "Magnetic Properties Experiment" on the Viking mission.