In less than 100 seconds, Tim O’Brien of the University of Manchester in the UK provides a fly-by tour of pulsar science. When the first pulsar signal was detected in the 1960s, for a short time it was referred to as “little green man 1” because the regular pulsing appeared to be a message from aliens. However, it did not take long for astronomers to figure out that these signals come from rapidly rotating neutron stars, which beam radiation from their magnetic poles.

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