Earth is drifting away from the Sun, but the movement is easy to confuse with a far larger orbital swing. The distinction matters. Earth's elliptical orbit brings it closer to and farther from the Sun on each trip around it, while a separate process slowly widens the orbit itself.
Distance makes a poor explanation for the seasons. Earth reaches perihelion, its closest point to the Sun, during Northern Hemisphere winter, when it is about 147 million kilometers away. At aphelion, it is roughly 152 million kilometers away. Axial tilt does the heavier lifting. Earth's axis leans about 23.4 degrees relative to a line perpendicular to its orbital plane, changing both the angle of sunlight and the length of daylight each hemisphere receives. When the north tilts away from the Sun, its days shorten and sunlight arrives at a shallower angle; the south experiences summer. The modest change in solar distance affects the intensity of sunlight, but it cannot account for opposite seasons occurring at the same time.
The long retreat is a quieter affair. The Sun loses mass through radiation and the solar wind, weakening its gravitational pull and gradually increasing the size of Earth's orbit. The effect is tiny. It does not mean Earth moves steadily outward at every moment, since the elliptical motion carries it inward and outward much more noticeably. Nor does it offer an escape from the Sun's changing output: the star is expected to grow brighter over immense timescales. For now, winter light falls across the north while Earth passes near its star.
