To understand why perihelion occurs in early January, it's essential to grasp some basic facts about Earth's orbit:
The closest the Earth gets to the sun is $$91.5 \text million miles$$.
It may seem counterintuitive that the Earth is closest to the Sun in January, when it's winter in the Northern Hemisphere. The reason for this discrepancy lies in the tilt of the Earth's axis, which is approximately 23.5 degrees. As the Earth orbits the Sun, its axis remains tilted in the same direction, resulting in the changing seasons. when is earth closest to the sun
Meanwhile, the Southern Hemisphere experiences the exact opposite. When it’s winter in New York (January), it’s summer in Sydney—even though Earth is closest to the sun.
The Earth is closest to the Sun every year in early January . This specific point in our planet's elliptical orbit is called perihelion Time and Date The Timing of Perihelion To understand why perihelion occurs in early January,
Scientists measure how stretched out an orbit is using a term called . A perfect circle has an eccentricity of zero. Earth’s orbit has a very low eccentricity of about 0.0167. This means our orbit is nearly circular, but that tiny deviation is still enough to cause a 3-million-mile variance in distance over the course of a year. Distance vs. Seasons: The Great Misconception
Earth’s current orbital eccentricity is incredibly low, sitting at approximately 0.01670.0167 As the Earth orbits the Sun, its axis
The opposite point, known as , occurs about six months later in early July. At that time, our planet will be its farthest from the sun at roughly 94.5 million miles (152.1 million kilometers) away. This means the sun's width in our sky is actually slightly larger at perihelion than at aphelion, though the difference is subtle and not noticeable without a telescope and proper solar filters.
The Earth is closest to the Sun around January 3rd or 4th every year. This date can vary slightly from year to year due to the elliptical shape of the Earth's orbit and the gravitational pull of other planets.
Astronomers use two specific terms to describe the extremes of this orbital journey:
