Like the lapis lazuli gem it resembles, the blue, cloud-enveloped planet the we recognize immediately from satellite pictures seems remarkably stable. Continents and oceans, encircled by an oxygen-rich atmosphere, support familiar life-forms. Yet this constancy is an illusion produced by the human experience of time. Earth and its atmosphere are continuously altered. Plate tectonics shift the continents, raise mountains and move the ocean floor while processes not fully understood alter the climate. Such constant change has characterized Earth since its beginning some 4. From the outset, heat and gravity shaped the evolution of the planet.
Take a tour through the fascinating geologic record left behind by the major milestones in Earth's 4. Here, we focus on the events that shaped the planet's surface, such as giant impacts and its oxygen-rich atmosphere. It's hard to know when the Earth first formed, because no rocks have survived from the planet's earliest days. While scientists disagree on the details, most researchers think Earth formed by a series of collisions that took place less than million years after the solar system coalesced. More than 10 impacts with other bodies added bulk to our growing planet, according to most models of Earth's formation. By measuring the age of rocks on the moon, and meteorites found on Earth, scientists estimate the Earth consolidated by 4. The young planet had established an atmosphere and iron core, when ….
Creationist Views of the Origin of the Universe, Earth, and Life
The history of Earth concerns the development of planet Earth from its formation to the present day. The geological time scale GTS , as defined by international convention,  depicts the large spans of time from the beginning of the Earth to the present, and its divisions chronicle some definitive events of Earth history. In the graphic: Ga means "billion years ago"; Ma , "million years ago". Earth formed around 4. Much of the Earth was molten because of frequent collisions with other bodies which led to extreme volcanism. While the Earth was in its earliest stage Early Earth , a giant impact collision with a planet-sized body named Theia is thought to have formed the Moon. Over time, the Earth cooled, causing the formation of a solid crust , and allowing liquid water on the surface. The Hadean eon represents the time before a reliable fossil record of life; it began with the formation of the planet and ended 4. The following Archean and Proterozoic eons produced the beginnings of life on Earth and its earliest evolution.
While Earth is only the fifth largest planet in the solar system, it is the only world in our solar system with liquid water on the surface. Just slightly larger than nearby Venus, Earth is the biggest of the four planets closest to the Sun, all of which are made of rock and metal. The name Earth is at least 1, years old.