A student was asked a question 'why are there summer and winter for us? He replied as 'since Earth is orbiting in an elliptical orbit, when the Earth is very faraway from the Sun (aphelion) there will be winter, when the Earth is nearer to the Sun (perihelion) there will be winter}. Is this answer correct? If not, what is the correct explanation for the occurrence of summer and winter?

Explanation

Early astronomers proved that Earth is spherical in shape by looking at the shape of the shadow cast by Earth in the Moon during lunar eclipse.