The sun has a core temperature of 15 million Kelvin and a surface temperature of 9,932 degrees Fahrenheit. It is 4.5 billion years old and will exist in its current form for another 5 billion years before running out of hydrogen. Solar flares are sudden bursts of radiation caused by collisions between magnetic fields on the sun's surface. The sun is the largest mass in the solar system and emits solar wind, which causes phenomena like the Northern Lights and affects spacecraft trajectories.