The Sun

The Sun is the star at the center of our solar system. It is a nearly perfect sphere of hot plasma that provides the energy that sustains life on Earth. The Sun accounts for 99.86% of the total mass of the solar system.

Key Facts About the Sun

• Diameter: 1,391,000 km (864,000 miles)
• Surface Temperature: 5,500°C (9,932°F)
• Core Temperature: 15 million°C (27 million°F)
• Age: 4.6 billion years
• Composition: 73% Hydrogen, 25% Helium
• Distance from Earth: 149.6 million km (93 million miles)

Nuclear Fusion

The Sun generates energy through nuclear fusion, converting hydrogen into helium in its core. This process converts about 600 million tons of hydrogen into helium every second, releasing enormous amounts of energy as light and heat.

Solar Activity

The Sun experiences an 11-year cycle of activity, producing solar flares and coronal mass ejections. These events can affect Earth's magnetic field and cause auroras near the poles. The Sun's outer atmosphere, the corona, is much hotter than its surface.