in 1821, alexis bouvard published the astronomical tables of the orbit of uranus. later observations showed that uranus was moving in an irregular way in its orbit. some astronomers thought this was caused by another large body. in 1843, john couch adams calculated the orbit of an eighth planet that could possibly affect the orbit of uranus. he sent his calculations to sir george airy, the astronomer royal. george airy asked adams for an explanation. in 1846, urbain le verrier made his own calculations but also failed to get much attention from french astronomers. in the same year, john herschel began to support the mathematical method and encouraged james challis to search for the planet. challis began his search in july 1846. meanwhile, le verrier had convinced johann gottfried galle to search for the planet.