the history of Vulcan to explain how its existence was tested and finally disproved, discussion help

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For centuries, astronomers could not explain the strange path by which the planet Mercury orbited the sun. Urbain Jean Joseph Le Verrier theorized in 1859 that Mercury’s strange orbit was the result of another planet interfering with the gravitational pull of the sun. Le Verrier named this other planet Vulcan.

Research the history of Vulcan to explain how its existence was tested and finally disproved.