<P> Because of the increased distance at aphelion, only 93.55% of the solar radiation from the Sun falls on a given area of land as does at perihelion . However, this fluctuation does not account for the seasons, as it is summer in the northern hemisphere when it is winter in the southern hemisphere and vice versa . Instead, seasons result from the tilt of Earth's axis, which is 23.4 degrees away from perpendicular to the plane of Earth's orbit around the sun . Winter falls on the hemisphere where sunlight strikes least directly, and summer falls where sunlight strikes most directly, regardless of the Earth's distance from the Sun . </P> <P> In the northern hemisphere, summer occurs at the same time as aphelion . Despite this, there are larger land masses in the northern hemisphere, which are easier to heat than the seas . Consequently, summers are 2.3 ° C (4 ° F) warmer in the northern hemisphere than in the southern hemisphere under similar conditions . </P>

Which part of earth is closest to sun