About 50 years after Uranus was discovered:
A)its rings were discovered.
B)the retrograde motion of its orbit was observed.
C)its orbit was too far off of its predicted path to be explained by observational errors.
D)it was discovered that it had more natural satellites than any other planet.
E)it was discovered that its atmosphere was featureless.

Question

Quizplus · Accepted Answer

C) Uranus was discovered in 1781 by William Herschel. About 50 years after its discovery, astronomers noticed that its orbit could not be accurately predicted by Newton's laws if only the known planets were considered. This discrepancy led to the hypothesis that another, yet unseen, planet was exerting a gravitational pull on Uranus. This eventually led to the discovery of Neptune in 1846, correcting the predicted path of Uranus's orbit.

About 50 Years After Uranus Was Discovered