On 2 January 1860, French astronomer Urbain Le Verrier announced the discovery of Vulcan, a hypothetical planet inside the Mercury orbit, to a meeting of the Académie des Sciences in Paris.
On October 21, 2003, a photograph of the nocturnal sky was taken and revealed a possible 10th planet in our solar system: Eris. Unfortunately scientists came then to the conclusion that Eris and also Pluto could no longer hold the status as planets and were called dwarf planets from this point.