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An animation shows how the seasons change with the earth’s orbit around the sun.
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The angle of the earth causes very specific weather and daylight patterns over the course of a year.
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Most places have four seasons, but they’re not as pronounced near the equator.
Astronomers believe that billions of years ago an object the size of Mars crashed into Earth, knocking our planet over and leaving it tilted.
That ancient bump is what caused Earth’s seasons, times of the year that have very specific weather patterns and hours of daylight that vary by latitude.
Most places experience four notable seasons: spring, summer, autumn, and winter. Below, see how the seasons change with Earth’s orbit around the Sun:
Eleanor Lutz, currently graphics editor at The New York Times, made the animation in 2019 using open data from NASA, USGS, and Natural Earth.
“I’ve always been very interested in designs that combine science and art. When I learned to code as part of my PhD in Biology, I wanted to apply coding to my design work as well,” Lutz told Insider. “I decided to make a series of astronomical maps, because there is a lot of wonderful open-source data in the astronomical community.”
The graph shows how seasonal changes in precipitation and temperature affect Earth’s ice, vegetation, cloud cover, and sunlight.
The tilt of the Earth relative to the sun causes the seasons
Earth is currently tilted 23.4 degrees from the plane in which most objects in the solar system orbit the sun, NASA explains. This means that as our planet travels in a nearly circular orbit around the sun, different parts of the globe receive different amounts of sunlight over the course of a year.
The Earth is divided into a northern and southern hemisphere by an imaginary ring called the equator. When the Northern Hemisphere is tilted towards the sun in June, it experiences summer. This is when the sun’s rays hit that part of the Earth most directly, heating the earth’s surface. When it’s summer in the northern hemisphere, it’s winter in the southern hemisphere.
Six months later, in December, the situation is reversed: the northern hemisphere is tilted to the sun and experiences wintry weather.
The tilt of the Earth’s axis also defines the duration of daylight hours, which are the shortest during the winter in each hemisphere. This is most dramatic at the planet’s poles, above the Arctic Circle.
In Utqiaġvik, Alaska, the northernmost city in the United States, darkness lasts from mid-November to mid-January.
Near the equator, the seasons are less pronounced, because the sun strikes at roughly the same angle each day. There, day length remains nearly 12 hours during all seasons.
The tilt angle of the Earth is relatively stable, but there are some small shifts over large time scales (tens of thousands of years). According to NASA, the angle is slowly decreasing.
Read the original article on Business Insider
