The surface of the sun is around 10,000° Fahrenheit. The corona (the outermost part of the sun’s atmosphere) reaches 3,600,000°F. This temperature is a big difference, and at the same time, is pretty small in real terms when considering that our entire solar system is roughly 25-30 million miles wide.

Insolation: The sun produces its heat through “conversion,” which is the fusion of hydrogen atoms into helium. This conversion process takes more energy than it has, so the sun’s core continues to heat up while producing only a little of its total energy. The outer layer of the sun, or photosphere, is roughly 10,000°F; the inner layers are much hotter.

The sun is a star from the Milky Way galaxy at the center of our solar system. It’s about 300,000 times larger than Earth—and for this reason, its mass equals 2 nonillions (that’s 2 followed by 30 zeros) kilograms. At a distance from Earth of around 150 million kilometers (93 million miles), it takes sunlight about 8 minutes to get from the sun to Earth.

The radiation from the sun is responsible for almost all life on Earth. The heat it generates provides the energy needed to evaporate water, which forms clouds that bring rain. Plants need sunlight to grow, and animals require food derived from plants or other animals that eat plants.

Humans can travel closer to the sun than we are now physically, but it would be hazardous. The crew of Apollo 12 got within 75 miles of the sun’s surface in 1969, but that is pretty much as close as humans will ever come to our star.

Besides this radiation, the sun plays a vital role in our lives. It has a tremendous influence on life on Earth. South of latitude 30°N or S, the sun produces all the heat needed for growth during half a year and obtains this energy from the southern hemisphere. For the rest of the year, its rays are cut off by the earth’s shadow at night to produce less heat.

The sun has an important influence on clouds produced by water evaporating from the earth’s surface; through this mechanism, it’s indirectly responsible for weather phenomena. The sun’s warmth also explains why there is little rainfall in regions near its poles (in each case, one-quarter of its surface area).

As our star, the sun does not provide us with light all of the time. Depending on the sun’s position concerning Earth and its axis, we experience night and day. The source of light during these periods is sunlight that has been scattered by particles in Earth’s atmosphere (called photons). At these times, the sky takes on a reddish-orange color, which is why sunrises and sunsets are generally red.