Take a break from your fun in the August sun to ask yourself: what do I really know about this giant glowing globe of plasma shining down on my picnic/game of Ultimate Frisbee/clothing-optional beach right now? Given that the Sun is what makes life on Earth possible, it's appalling how much misinformation we've been fed about our nearest star. Speaking of our nearest stars: Ken Jennings, that one guy from Jeopardy!, may not be as bright as the Sun, but he's an expert on debunking myths and misconceptions. All month, he'll be lighting up our stellar misconceptions regarding the sun.
The Debunker: Is the Earth Closest to the Sun in the Summer?
Yes, the Earth is closer to the sun in the summer! But only if you live in the Southern Hemisphere. If you're not Argentine or Australian, read on.
The Earth's orbit around the Sun (which—bonus Debunker!—was not first discovered by Copernicus, but was actually hypothesized thousands of years earlier by Greek astronomers like Aristarchus) is often drawn in children's books and even textbooks as a fairly elongated ellipse, but it's actually close to a circle. The difference between Earth's perihelion, its closest orbital point to the Sun, and its aphelion, the furthest point, is only about 3 million miles, a difference of just 2 percent.
Diagrams of a very oval orbit give many otherwise-not-dumb people that idea that the seasons might be caused by orbital distance, that Earth's summer corresponds with perihelion and winter with aphelion. But, as a moment's thought will reveal, that's impossible! When it's summer in the Northern Hemisphere, it's winter down south. That can't be a function of orbital distance.
In fact, the seasons are a result of axial tilt: the Earth's poles are not lined up perpendicular to its orbital plane, but rather 23.5º away from vertical. This means that there's always one half of the Earth tilting toward the Sun (causing the warm temperatures of summer) and one half tilting away (that would be winter). The Earth is actually closest to the Sun around January 3—far from the dog days of summer for most Earthlings.
Quick Quiz: The first Four Seasons hotel was actually not a five-star luxury destination, but a humble "motor inn" in what Canadian city?
Ken Jennings is the author of six books, most recently his Junior Genius Guides, Because I Said So!, and Maphead. He's also the proud owner of an underwhelming Bag o' Crap. Follow him at ken-jennings.com or on Twitter as @KenJennings.