Final answer:
Solar radiation varies in angle due to the 23.5° axial tilt of Earth as it orbits the Sun, leading to different seasons. The misconception that the change in distance from the Sun causes the seasons is inaccurate. The angle of sunlight, affected by Earth's axial tilt, is the primary reason for seasonal temperature variations.
Step-by-step explanation:
The reason solar radiation strikes different parts of Earth's surface at varying angles throughout the year is due to Earth's 23.5° axial tilt. During the summer solstice, the Northern Hemisphere is tilted towards the Sun, causing the solar rays to hit this region more directly, resulting in higher temperatures and longer days. Contrarily, during the winter solstice, the Northern Hemisphere tilts away from the Sun, resulting in rays striking at a shallow angle, spreading out over a larger area, thus having less heating efficiency which leads to colder temperatures and shorter days.
The misconception that Earth's distance from the Sun dictates the seasons is not accurate. The Earth's orbit causes only a 3% variation in distance, which is insufficient to account for the significant temperature changes we experience. Instead, it is the angle of sunlight, due to the tilt of Earth's axis, which matters most. This tilt leads to varying angles of sunlight throughout the year as Earth revolves around the Sun, causing the different seasons experienced in each hemisphere.