Okay, I'm a few days late on this, but Happy Perihelion! Perihelion refers to Earth's closest approach to the Sun in its one year orbit. The Earth's orbit is slightly elliptical (not a perfect circle). As a result, Earth's distance to the Sun changes. However, this change in distance is NOT what gives us the seasons. Earth's seasons are a result of Earth's 23.5 degree axial tilt. For more details on seasons, refer to my earlier post on seasons.
On Saturday, January 4 at 7 AM Eastern Standard Time the Earth was at its closest distance to the Sun in 2014 with a distance of 91.4 million miles. When the Sun is at aphelion, its farthest distance from the Sun (July 3, 2014) it will be about 3 million miles farther away. Three million miles seems like a large distance, but compared to 91-94 million miles, that isn't a large distance. It's certainly not enough to cause our seasons. If it was, then we would have summer in the Norther Hemisphere in January and winter in July. Since we don't, we know that distance doesn't cause the seasons.
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