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.

Watch more from our 100 Second Science video series.