The Sun

The Sun, an average-sized, middle-aged star, formed almost 5 billion years ago from a cloud of gas and dust.

Photo by SOHO / ESA / NASA Size: About 109 Earths would fit side-by-side across the face of the Sun! One million Earths could fit inside the Sun. One large sunspot could hold several Earths. The Sun's diameter is 864,000 miles (1.4 million kilometers). Distance from Earth: The Sun is about 93 million miles (150 million km) away from Earth. Rotation: The Sun spins on its axis from east to west. Its equatorial zone rotate once every 24 days approximately, while its polar regions take over 30 days to rotate once. Surface: Heat, deep inside the Sun, rises from the radiative zone through the convective zone until it bubbles at the surface, the photosphere. At the photosphere, things cool a bit and the gas begins to sink back down through the convective zone. When gas reaches the radiative zone, it heats up and the whole process starts over again.

The photosphere is the layer that holds sunspots. The photosphere is churning and boiling like a thick pot of chili or oatmeal. Although sunspots are very hot, they are slightly cooler than the rest of the photosphere, so they look darker. Sunspots have a dark center called an umbra and a lighter ring around the outside called the penumbra. It takes 50 million years for the energy formed deep inside the Sun to reach Earth. Earth only gets one-billionth of the total energy produced by the Sun.

Atmosphere: The Sun's outer atmosphere is called the corona, and its inner atmosphere is called the chromosphere. Temperature: The temperature at the Sun's core is 15 million kelvins. Other information: The Sun formed about 5 billion years ago from a huge cloud of gas and dust. The Sun is an average-size, middle-aged star. The Sun's core converts 700 million tons of hydrogen gas into 695 million tons of helium gas every second. The remaining 5 million tons of matter are converted to an amount of pure energy that's about six hundred times greater than the amount of water flowing over Niagara Falls produces in one second. Light, traveling at 186,000 miles (300,000 km) per second, takes just over 8 minutes to reach Earth from the Sun. In both Greek and Roman mythology, Apollo is the god of the Sun. He brought life-giving heat and light to Earth and was the patron god of musicians and poets.