The Freezing Void
If you stepped out of a spaceship without a suit, you wouldn't feel the 'warmth' of the Sun like you do at the beach. Instead, you would freeze instantly. Outer space is about -455 degrees Fahrenheit.
This creates a huge mystery: if space is freezing cold, how does the Sun's heat get to Earth? On Earth, heat moves through air or water, but there is no air in space to carry the warmth. The answer lies in a special kind of travel.
Radiation: The Light Rider
The Sun doesn't send 'heat' through space; it sends 'radiation.' This radiation is made of waves of energy, including visible light and invisible infrared light. Unlike sound or heat on Earth, these waves don't need 'stuff' to move through.
Light and radiation can zip through the empty vacuum of space at 186,000 miles per second. They are the ultimate long-distance travelers, making the 93-million-mile trip from the Sun to Earth in just over eight minutes.
The Invisible Flashlight
Think of the Sun like a giant flashlight in a dark room. The beam of light travels through the air, but you can't see the light until it hits a wall. Space is like the empty air in that room.
The Sun's energy passes through the empty space without warming it up because there is nothing for the energy to hit. Space stays cold because there are no molecules to catch the sunlight and turn it into heat.