What important discovery was made by edmond halley and alexis clairaut, using newton's ideas of mathematics and gravity? a. they explained why objects appear to have color. b. they were able to find the orbit of a comet and predict the year of its return. c. they discovered the three newest planets--uranus, neptune, and pluto d.

The correct answer is option B.

Edmond Halley correctly predicted the return of the eponymous comet Halley after he realized several sightings of a comet were in fact the same comet.

By correctly understanding Sir Isaac Newton's law of gravity and also his ideas in mathematics, Halley was able to correctly predict that the comet that now bears his name would return periodically. He did this by discovering Halley's orbit in 1716 and thus being able to predict the year of its return.

thomas jefferson is the answer