Transcript: In 1967 Jocelyn Bell, a graduate student working at a radio telescope in Cambridge, England, noticed an unexpected source of radio emission that pulsed every one and a third seconds. Through careful detective work she and her coworkers were able to rule out artificial sources for the radio waves and proved that they came from a celestial source. Radio pulsing stars were unexpected and unanticipated. If the pulse was due to rotation, the size of the star must be less than five thousand kilometers, making them much smaller than normal stars. For a while she and her group jokingly referred to the objects as LGM 1, 2, 3, and so on, where LGM stood for Little Green Men. They were not alien signals, nor were they artificial. Pulsars were the long sought after neutron stars. Antony Hewish and Martin Ryle, heads of the labs at Cambridge, received the Nobel Prize for this discovery. Controversially, Jocelyn Bell who actually made the discovery did not share in the Nobel Prize.