With 150 million km, our home planet, Earth, has just the right distance from the sun to maintain liquid water and an atmosphere. Light from the sun reaches the earth in 1.3 seconds. This distance of 150 million km is called an astronomical unit (1 AU).
The Earth is the largest rock planet with a liquid core, consisting of iron and nickel ,and a crust, consisting of silicates, oxides and traces of other elements. The atmosphere, which is only 640 KM high, consists of nitrogen (78%), oxygen (21%), inert gasses (1%), CO2 (.04%) and water vapor.
The Earth is the only planet on which liquid water, higher life forms and breweries are found.
The seasons result from the 23 degree tilt of the earth’s axis against the earth’s orbit during a cycle of the sun.
The moon orbits the Earth at a distance of 384,000 km within 27.3 days, always showing us its same side. It stabilizes the direction of the Earth’s axis and prevents the earth from teetering any further.