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On October 19th, 1967, astronomers at the Jodrell Bank Observatory in England made a groundbreaking discovery that would change our understanding of the universe forever. Using the Lovell Telescope, then the world's largest steerable radio telescope, they detected rapid pulses of radio waves coming from a distant point in space.

These mysterious signals, arriving with clockwork precision every 1.3373 seconds, were unlike anything astronomers had ever seen before. Initially, the team jokingly referred to the source as LGM-1, short for "Little Green Men," entertaining the far-fetched notion that they might be picking up signals from an alien civilization.

However, the truth turned out to be even more fascinating. The signals were coming from a rapidly rotating neutron star, or pulsar, now known as CP 1919 (Cambridge Pulsar 1919). This discovery marked the first time humans had detected a pulsar, opening up an entirely new field of astrophysics.

Pulsars are the remnants of massive stars that have exploded as supernovae. These incredibly dense objects, about the size of a city but with the mass of a star, spin at mind-boggling speeds, emitting beams of electromagnetic radiation from their magnetic poles. As the pulsar rotates, these beams sweep across space like a cosmic lighthouse, appearing to pulse from our vantage point on Earth.

The discovery of pulsars not only provided evidence for the existence of neutron stars, which had been theorized but never observed, but also gave scientists a new tool for studying the universe. Pulsars have since been used to test Einstein's theory of general relativity, measure the density of interstellar medium, and even create a galactic-scale gravitational wave detector.

So, the next time you look up at the night sky, remember that among the twinkling stars, there are these cosmic lighthouses, spinning rapidly and sending out regular pulses of radio waves – a testament to the wonders that still await our discovery in the vast expanse of space.

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