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Milky Way

supernova remnants

colossal stellar

filaments 

pulsar -- a natural

extraterrestrial 

Scattered among the stars of the Milky Way are supernova remnants, each one the remains of a colossal stellar explosion. These filaments of glowing gas are the outer layers of a star which has recently destroyed itself. The gas is unraveling, returning star stuff back into space. And at its heart are the remains of the original star, a dense shrunken stellar fragment called a pulsar -- a natural lighthouse blinking and hissing, a sun that spins twice each second. Pulsars keep such perfect time that the first one discovered was thought to be a sign of extraterrestrial intelligence, perhaps a navigational beacon for great ships that travel across the light years and between the stars.

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