Hobbies And Interests
Orbit
The gravitational field generated by the sun is incredibly strong. Although the sun is, on average, 93 million miles from the earth, it is the sun's gravitational field which causes the earth to orbit the sun and to rotate on its axis. Without the gravity from the sun the earth would float off into space. Additionally, if the gravity field didn't hold the earth exactly where it is, life here might not be possible. If the earth were closer to the sun it could be too hot; if it were farther from the sun it could become too cold.
Seasons
Over the course of every year the earth moves slightly closer to and slightly farther from the sun at the same time the earth tilts slightly on its axis. About March 20 every year the Northern Hemisphere begins to tilt toward the sun, and the Southern Hemisphere slightly away. This is called the vernal equinox, and it means the start of spring for the north and the start of fall for the south. The summer solstice begins around June 20 and marks the point where the earth is tilted the most toward the sun and the south the furthest away, which means summer for the Northern Hemisphere and winter for the Southern Hemisphere. After that the process begins to reverse. Around September 20 the autumn equinox marks the start of fall in the north and spring in the south and around December 20 the South Pole is the closest to the sun, meaning winter for the north and summer for the south.
Energy
The sun can be thought of as a giant power plant. It converts 4 million tons of matter into energy every second and deposits, on average, 342 watts of energy onto every meter of the planet every year. When people use solar energy it is this energy they are capturing. Plants also capture this energy; when wood is burned in a fireplace it is the solar energy, captured by the tree, that is released to generate heat. Even fossil fuel comes originally from solar energy. The plants and animals captured solar energy millions of years ago and then were slowly buried. The plants and animals decomposed and the energy condensed into gas and oil.
Atmosphere
When the earth was originally formed and cooled it released a tremendous amount of gas. Some of this gas was held in by the gravitational pull and formed the beginning of the earth's atmosphere. Over time more gases were added to the atmosphere, the sun's heat caused water to evaporate, volcanoes erupted releasing other gases, and as life developed living creatures released gases into the atmosphere. All of these gases act as a filter in two ways. They reduce the ultraviolet radiation of the sun before it reaches the earth and they trap in some of the sun's heat when it is radiated back up, which helps to prevent the planet from becoming too hot or too cold.