On this day in 1968 – February 24th – the discovery of the first pulsar was announced.

A pulsar is a fast-rotating neutron star that emits a beam of electromagnetic radiation. We can only detect it when it's pointing towards us, rather like a lighthouse, so it seems to pulse. A neutron star is the remnant of a massive star following the collapse of its core in a supernova explosion.

Mona Evans
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