Updated January 4, 2025 at 9:00 p.m.
The annual moment has arrived: the Earth is at perihelion. Explanations.
Five million kilometers closer
Every year, our planet reaches perihelion. This is the time when Earth is closest to the sun in its orbit. The event occurred Saturday morning, at 8:28 a.m. local time.
In short, since the Earth is located at perihelion, it is 147 million kilometers from its star, or five million kilometers closer than when it reached aphelion. Perihelion therefore occurs after the winter solstice, while aphelion occurs after the summer solstice.
*Good to know: cyclically, over a period of approximately 100,000 years, the Earth’s eccentricity varies between a more elliptical orbit and a more circular orbit. Thus, in the history of the Earth, perihelion has happened to coincide with the summer solstice. *
The shortest season
Did you know that the seasons are not the same length? As meteorologist Carol-Ann Veilleux explains, “since the orbit of the Earth’s rotation around the Sun is elliptical, the distance between the two varies; it is the law of conservation of angular momentum which explains why as the distance decreases, the rotation speed in the orbit must increase to compensate and conserve angular momentum”. For these reasons, astronomical winter, in the Northern Hemisphere, is the shortest season of the year: it lasts on average 89 days, compared to 93.6 days for summer.
You would think that perihelion would provide us with warmer weather. However, the cold temperatures in the Northern Hemisphere during the winter solstice are due to the tilt of the Earth.
