A pulsar is a rapidly spinning neutron star that emits massive amounts of radiation in rapid pulses that occur at regular intervals. A neutron star is created when the central part of a massive star collapses. The atoms in the star are crushed completely, and the electrons are jammed inside the protons to form a star composed almost entirely of neutrons. The result is a tiny star that is like a gigantic nucleus and has no empty space — an extreme state of matter. Because of its extreme state, a neutron star has extremely strong gravitational and magnetic fields. If the neutron star is rotating rapidly, the strong magnetic fields combined with rapid rotation create an awesome generator that can produce electric potential differences of trillions of volts. Such voltages are 30 million times greater than those of lightning bolts. Scientists using the Chandra X-ray Observatory recently observed one of the strongest pulsars known, the rapidly spinning neutron star B1509-58, located 19,000 light years away in the constellation of Circinus. The closeup look is yielding data that will allow astronomers to test theories of how a pulsar generates so much energy.