Book 22, Question 51
How Does the Sun’s Energy Cross Empty Space to Reach Us?
The space between the Sun and Earth is almost completely empty. There is no air to carry heat across it. So how does sunshine get here?
More fun facts
- Deep in the sun's core, hydrogen is fused into helium, and these nuclear reactions power its heat and light.
- Light is made when moving charged particles, such as electrons, create electromagnetic fields that carry energy.
- Energy from the core bounces around inside the sun for about 170,000 years before reaching its outer layers.
- Water waves and sound waves need matter, called a medium, to travel through.
- Light is an electromagnetic wave, and it does not need any matter to travel through.
- That is why sunlight can cross the empty vacuum of space to reach Earth.
- Earth's atmosphere blocks many of the sun's most harmful high energy waves, such as X-rays and gamma rays.
Sources: NASA Science, NASA Science, NASA Science
Questions kids ask
How do sound waves pass energy along?
They make molecules bump into each other, passing energy along like falling dominoes.