The Sun is about 865,000 miles in diameter. That's as wide as 109 Earths placed side by side! About 1 million Earths would fit inside the Sun.
It's hard to imagine the enormous amount of energy the Sun produces. Because its core is under a lot of pressure, hydrogen atoms are constantly colliding with each other at great speeds, fusing together to form helium, and releasing energy. Lots of these collisions occur, creating a ball of energy.
In just one second, the Sun produces about 118 times as much energy as the United States used in the year 2003! Only about one-billionth of the total energy that the Sun produces reaches Earth, but it is enough to enable us to live here.