Today, the Earth quietly reached perihelion, the point in its orbit when it is closest to the Sun. Our planet was about 147 million kilometres (91.4 million miles) from the Sun, the nearest it gets all year. It’s a fascinating cosmic milestone, but don’t expect a sudden burst of warmth, winter is still very much here to stay.
Many people assume that being closer to the Sun should make it hotter. The truth is, Earth’s seasons are ruled not by distance but by the tilt of its axis. The planet is tilted about 23.5 degrees, and in early January, the Northern Hemisphere leans away from the Sun. This means sunlight hits the ground at a slant, days are shorter, and the air stays cold, all the classic signs of winter.
Earth’s orbit isn’t a perfect circle, so its distance from the Sun changes slightly throughout the year. At perihelion, Earth is roughly 3% closer to the Sun than at aphelion, its farthest point in July. While this makes a small difference in the amount of solar energy we receive, it’s nothing compared with the effect of the tilt.
Perihelion also has a subtle influence on Earth’s journey around the Sun. As our planet nears the Sun, it moves a bit faster along its orbit, slightly shortening the time from winter to spring in the Northern Hemisphere. Over thousands of years, these orbital quirks even contribute to long-term climate patterns known as Milankovitch cycles.
Astronomers and climate scientists track perihelion to better understand Earth’s seasons, aid satellite navigation, and improve climate models. But for most of us, it’s a gentle reminder that the warmth of summer or the chill of winter comes from the angle of sunlight, not how close we are to our star.
So, while the Sun is at its nearest, wrap up warmly, winter isn’t ready to let go just yet.
