NASA - National Aeronautics and Space Administration

Image above: The sun rises and starts a new day. Credit: Ideum

Each day begins when the morning sky gets light. It starts in the east. We first see light at the horizon. That is where the Earth meets the sky. We know the sun will rise each morning. Yet, we hardly ever stop to think about what is happening or why. Have you ever wondered what mysteries the sun holds?

NASA scientists are learning more about the sun. The sun is the closest star to Earth. The sun is millions of miles away. It is so big that over 100 Earths could fit across it. It is a giant ball of hot, moving gases. You can see this in pictures of the sun taken by a telescope. The sun sends energy to Earth and other planets in our solar system. We know this when we feel heat. We know this when we see sunlight. Without the sun, there would be no life on Earth.
 
Sun Watchers

Image above: Windows were put in special places to catch the sunlight. Credit: Ideum

Scientists today study the sun with special tools. They use satellites and telescopes. But sun watching isn't new. People have been looking at the sun for a very long time. They learned that the sun goes through changes. And, they used what they learned. It helped them know when to plant crops or get ready for winter. They also learned when the seasons would change. Do you know when the seasons are ready to change? What clues do you look for?

The sun watchers of long ago looked at the sun day after day, year after year. They saw that the sun rose and set in a different place every day. They saw that rays of light from the sun hit different places as the year went by. They built windows and doors in special places. These would catch the sun's rays. Looking at where sunlight hit made a kind of calendar. It let the early sun watchers keep up with important times of the year.

Why do you think it's important to know when to plant or pick crops?

Adapted from Traditions of the Sun
NASA Sun-Earth Connection Education Forum
UC Berkeley