earth

Earth is the third planet from the sun and the densest and fifth-largest of the eight planets in the solar Systems four terrestrial planets.it is sometimes reffered as the world,the blue planet,or by its latin name terra.
Home to millions of species including humans,earth is currantly the only astronomical body where life is knowned to exsit.The planet formed 4.54 billion years ago,and life appeared on its surface within one billion years.earths biosphere has significantely altered the atmosphere and other abiotic conditions on the planet.enabiling the proliferation of aerobic organisms as well as the formation of the ozone layer which,together with earths magnetic field,blocks harmful solar radiation,permitting life on land.The phisical properties on the earth,as well as its geological history and orbit,have allowed life to persist during this period.The planet is expected to continue supporting life for at least another 500 million years