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Earth at Perihelion

StarDate: 
January 3, 2011

With the winter solstice just a couple of weeks behind us, there's still not much sunshine to warm things up across most of the United States. For much of the country, early January is the coldest time of year -- a fact that probably won't come as much of a surprise.

What may surprise you, though, is that we're actually closest to the Sun for the entire year today -- about one and a half million miles closer than the average distance of 93 million miles.

Because Earth's distance from the Sun changes, so does the amount of solar energy our planet receives. We get about seven percent more sunlight at this time of year than when we're farthest from the Sun, in early July.

Although that's not a large number, you might still expect it to produce a pretty good swing in the planet's climate -- but it doesn't.

That's largely because the oceans act as a climate storage battery -- they store heat and circulate it around the globe. And it takes a lot of extra energy to make much of a change in the overall ocean temperatures. So by the time the oceans start to warm up from the extra sunshine, the planet is already a good bit farther away from the Sun, so any extra energy that's been stored up begins to radiate back into space. That keeps the climate on a fairly even keel all year long.

So if you find your own spot in the sunshine, soak up that extra bit of solar energy -- and think ahead to the longer, warmer days of spring.

Script by Damond Benningfield, Copyright 2010

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