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For centuries, most people thought the Sun went around Earth. Every sunrise and sunset seemed to prove this.
In 1543, the Polish astronomer Nicolaus Copernicus said the Earth actually went around the Sun! As Earth turns, it spins on its axis. That’s why it looks like the Sun rises in the east and sets in the west.
This idea shocked people. It took a while to catch on. Once it did, it explained why seasons and eclipses occurred.
▲ Nobody is sure why Stonehenge was built in southern England around 2500 B.C. We do know that the huge stones line up perfectly to mark the sunrise on the solstices and equinoxes. That’s why some believe Stonehenge was a temple for Sun worship.
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Was Copernicus the first to say that Earth moves around the Sun?
No. Way back in 260 B.C., the Greek astronomer. Aristarchus said Earth went around the Sun. But his theory was never popular.
Earth’s Seasons
We have seasons because Earth tilts 23 degrees. Some places get more sunlight than others at different times of the year. When the North Pole slants toward the Sun, the planet’s northern half (or hemisphere) enjoys the summer’s warmth. When the South Pole slants toward the Sun, it’s summer below the equator. Spring begins when a pole starts to slant toward the Sun. Fall begins when a pole starts to slant away.
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When does the Sun shine at midnight?
Near the Northern Hemisphere’s summer solstice, the Sun shines all night at the North Pole. In fact, the Sun can be seen for six months (from March until September). Near the Northern Hemisphere’s winter solstice, the North Pole is dark for six months. That’s when the Sun never stops shining at the South Pole.
Solar Eclipses
A solar eclipse happens when the Moon blocks the Sun’s light over a part of Earth. How can something 400 times smaller than the Sun block its rays? That’s because the Moon is 400 times closer to Earth than the Sun. So it appears to fit right over the Sun.
▲ Annular Eclipse
When the Moon is at a far point in its orbit, it can’t block all the Sun’s rays. That leaves an annulus, or ring. It’s brighter than a corona.
▲ Total Solar Eclipse
The Moon blocks out the entire Sun. The only part of the Sun we can see is a faint halo of light. It’s called a corona.
▲ Partial Solar Eclipse
The Moon doesn’t block the entire Sun.
During a solar eclipse, the Moon’s shadow on Earth is very narrow. It’s no more than 168 miles wide. So even though about three total solar eclipses occur every four years, few people in any one place see them. Only eight will be visible from the continental U.S. during the twenty-first century. ▼
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Why do we use the word solar to describe things about the Sun, like solar heat or solar system?
It comes from the Latin word for Sun, which is sol.
Sun Facts
Temperature
About 10,000 degrees Fahrenheit on the surface and about 27 million degrees at its core
