Earth's Seasons

Earth's seasons — winter, spring, summer and autumn(or fall) — are caused by the yearly revolution of the Earth in its orbit around the sun and the planet's tilt. When the Northern Hemisphere is pointed toward the sun, it is summer, and when it is pointed away, it is winter (and vice versa for the Southern Hemisphere). Summer and winter are heralded by their respective solstices, while spring and fall begin at an equinox, when the sun crosses Earth's equator and night day are roughly equal length. Below, our stories that relate to Earth's seasons and the ways they affect us.
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Why Spring Gets About 30 Seconds Shorter Every Year
people in a park in San Francisco
March 19th, 2015
Spring arrives on Friday, and you might want to make the most of it. The season of flowers and showers actually gets shorter every year by about 30 seconds to a minute, due to astronomical quirks, researchers say.
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Snowvember: What's Causing the Unseasonably Cold Weather?
Satellite image of Typhoon Nuri.
November 13th, 2014
The polar vortex isn't the only weather system to blame for your frozen fingertips.
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Pew, Pew: Bizarre Sounds from Frozen Lake Explained
coolest sound ever
October 16th, 2014
What causes the weird sounds produced by skipping rocks across a frozen lake?
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5 Weird Ways Cold Weather Affects Your Psyche
Women in cold snow
March 11th, 2015
Freezing temperatures and snow have turned much of the United States into an icebox. But, beyond keeping people inside and prompting them to bundle up when they venture out, does the cold weather change people's behavior?
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Why Flu Strikes in Winter
sneeze-woman-tissue-100928-02
October 30th, 2014
Winter is almost here, and that means a likely increase in people falling ill from flu. But why is flu season in winter anyway?
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6 Trees That Are Easier to Identify in Fall
The colorful foliage of autumn
October 6th, 2014
Many trees put on a show in fall, with their leaves turning hues of orange, yellow, red, purple and brown. But these changing colors can also serve as a marker to help identify trees.
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Saturday Solstice Marks Official Start of Summer
Summer Beach
June 20th, 2014
The summer solstice will occur Saturday (June 21), marking the official start of summer.
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Human Hibernation: Snowy States Cause Longer Slumbers
This map of the U.S. shows the regions where people got the most (northern states) and least (southern states) amount of sleep.
February 24th, 2015
People in snowier states appear to sleep for a little longer during winter months than those in sunnier states.
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Winter Forecast for US Nothing to Shiver About
2014 winter weather outlook
October 16th, 2014
Don't expect the polar vortex to pummel the eastern United States this winter.
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Hot and Getting Hotter: Heat Islands Cooking US Cities
planet, planets, round, why, sphere, spheres, spherical, bulge
August 21st, 2014
Since 1970, cities have been warming, and have been getting hotter far faster than adjacent rural areas
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