Earth is the third planet from the Sun, it is the planet we live on and it is maybe the only planet in our solar system which contains life. Its place are enough hot and enough cold for life to grow as it did. Its surface temperature is around 15 °C. The Earth’s molten nickel-iron core spins very fast and creates a protective magnetic field. The Sun’s winds are stopped by this magnetic field. Furthermore, the large atmosphere protects us from the meteorites which burn before arriving on the Earth’s ground. The Earth is the biggest non-gas planet. From the space, Earth appears blue, green and brown. Earth is old and has change since its birth. In the past, meteorites were numerous and the oceans were at their beginning. Then life appears and the ecosystem started to stabilize. Several theories exist to explain the Earth’s moon birth but none are good enough.
Earth is the symbol of life in its whole. It was known as the center of universe for the Romans but nowadays this idea is even not considered. We should note that is only a matter of point of view. Indeed, astrology for example us the geocentric point of view which seems more obvious as we are on Earth. The science uses the solar centric point of view because of the Newtonian perspective. Earth is also the symbol of fertility and self consciousness. No one knows if it is only Earth which contains life even if it seems obvious in our infinite universe that it should exist life somewhere else.
Earth is not yet completely known and our technology is not enough advanced to study it yet. Antarctica, for example is not known at all. 4500 km of ice covers it in some zone. We have also difficulties to study the oceans where in some point the depth is about 11000 km. The moon is also a mystery, how did it become our moon? We discover everyday new species, new elements, new theories about the Earth, its past and its evolution. Earth is a mystery as the life is. In the future, we will learn more, but as everything is, Earth is infinite and an infinite time is needed to completely understand the Earth and the life which has appeared on it.