Contrary to what might be expected, the elliptical shape of Earth's orbit around the Sun does have an impact on its seasons. In fact, it is one of the key factors that contribute to the changing seasons on our planet. The phenomenon of seasons is primarily caused by the tilt of Earth's axis of rotation, but the elliptical orbit does play a secondary role.
The tilt of Earth's axis, which is currently about 23.5 degrees relative to its orbital plane, is the main reason why we experience different seasons throughout the year. As Earth orbits the Sun, different parts of the planet receive varying amounts of solar radiation due to the tilt. When one hemisphere is tilted towards the Sun, it receives more direct sunlight and experiences summer, while the other hemisphere is tilted away and experiences winter. During the equinoxes, neither hemisphere is tilted towards or away from the Sun, resulting in spring and autumn.
The eccentricity of Earth's orbit, which determines its elliptical shape, does affect the intensity of solar radiation received by the planet at different points in its orbit. However, the effect of eccentricity on seasons is relatively minor compared to the axial tilt. This is because the difference in distance between the Earth and the Sun at different points in its orbit is relatively small compared to the effect of the tilt.
The eccentricity of Earth's orbit is currently about 0.017, which means that the orbit is very close to being circular. The variation in the distance between Earth and the Sun over the course of a year is only about 3.1 million miles (5 million kilometers), which is a small fraction of the average distance of approximately 93 million miles (150 million kilometers). Therefore, the impact of eccentricity on the seasons is overshadowed by the dominant influence of axial tilt.
In summary, while the elliptical shape of Earth's orbit does have some influence on the distribution of solar radiation throughout the year, it is the tilt of Earth's axis that is the primary driver of the seasons.