23.5-degree tilt of the Earth's axis. During the Northern Hemisphere's winter, that half of the planet is tilted away from the Sun, receiving less direct sunlight and experiencing shorter days, even though the planet is physically closer to its star. Subtle Orbital Effects Although the distance change is too small to dictate the seasons, it does have a minor impact on our journey through space. According to Kepler’s Laws, planets move faster when they are closer to their star. Consequently, the Earth travels at its highest orbital speed during perihelion in January, which makes the Northern Hemisphere's winter (and the Southern Hemisphere's summer) about five days shorter than the opposite seasons. Would you like to explore how
By contrast, when the Earth reaches its farthest point, known as , it sits about 152 million kilometers (94 million miles) away. This occurs in early July. Why Does It Happen in Winter? sun closest to earth
Perihelion is not a fixed date on our calendar. Due to a slow, cyclical wobble in Earth’s axis (called apsidal precession), the date of perihelion drifts forward by about one day every 58 years. Over thousands of years, this drift—combined with changes in the shape of the orbit (eccentricity) and the tilt itself (obliquity)—creates the Milankovitch cycles, which are linked to the onset and retreat of ice ages. About 10,000 years ago, perihelion occurred during the Northern Hemisphere’s summer, creating much hotter summers and colder winters—a key factor in the end of the last glacial period. According to Kepler’s Laws, planets move faster when
There is a common misconception regarding the relationship between seasons and distance from the Sun. Many assume that summer occurs when Earth is closest to the Sun and winter when it is farthest away. However, the reality of our cosmic dance is far more nuanced. This occurs in early July
To grasp perihelion, we must first abandon the idea of a perfectly circular orbit. While often illustrated as a neat circle, Earth’s path around the Sun is a very slight ellipse—an oval shape. The Sun is not at the center of this ellipse but offset at one of its two focal points. Consequently, Earth’s distance from the Sun changes gradually over the course of a year.