The sun, indisputably, is the single most important influence on Earth. We wouldn t be here if it weren t for our medium-sized, ordinary star. It provides the energy that warms us, makes plants grow, and drives the weather across the globe. The sun s energy, by heating different parts of the surface of our planet, creates winds, evaporates water that then falls to the surface as rain or snow, and provides the massive power that fuels hurricanes and tornadoes. If we were farther away, like Jupiter and Saturn, we would be too cold.
Earth is located in the life zone, an area of moderate warmth around a star.
We also have the good fortune of having a nearly circular, stable orbit within this zone, which means our temperatures don t fluctuate wildly. And, happily, our planet also has a liquid outer core whose convection currents generate Earth s magnetic field and has turned us into a planet-sized magnet. Earth s magnetic field produces our planet s magnetosphere. The easiest way to picture the invisible lines of force within the magnetosphere is to remember playing with bar magnets and iron filings. The Earth s magnetic field does the same thing.