Search results
Results From The WOW.Com Content Network
The geological history of the Earth follows the major geological events in Earth's past based on the geological time scale, a system of chronological measurement based on the study of the planet's rock layers ( stratigraphy ). Earth formed about 4.54 billion years ago by accretion from the solar nebula, a disk-shaped mass of dust and gas left ...
The history of Earth is divided into four great eons, starting 4,540 mya with the formation of the planet. Each eon saw the most significant changes in Earth's composition, climate and life. Each eon is subsequently divided into eras, which in turn are divided into periods, which are further divided into epochs . Eon.
Historical models of the Solar System. Approximate sizes of the planets relative to each other. Outward from the Sun, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Jupiter's diameter is about 11 times that of the Earth's and the Sun's diameter is about 10 times Jupiter's.
c. 4,300 Ma – Nectarian Era begins on Earth. c. 4,250 Ma – Earliest evidence for life, based on unusually high amounts of light isotopes of carbon, a common sign of life, found in Earth's oldest mineral deposits located in the Jack Hills of Western Australia. [4] c. 4,100 Ma – Early Imbrian Era begins on Earth.
The British Empire (red) and Mongol Empire (blue) were the largest and second-largest empires in history, respectively. The precise extent of the Mongol Empire at its greatest territorial expansion is a matter of debate among scholars. Several empires in human history have been contenders for the largest of all time, depending on definition and ...
Nevertheless, ancient Archaean lead ores of galena have been used to date the formation of Earth as these represent the earliest formed lead-only minerals on the planet and record the earliest homogeneous lead–lead isotope systems on the planet. These have returned age dates of 4.54 billion years with a precision of as little as 1% margin for ...
History. According to evidence from radiometric dating and other sources, Earth formed about 4.54 billion years ago. The current dominant theory of planet formation suggests that planets such as Earth form in about 50 to 100 million years but more recently proposed alternative processes and timescales have stimulated ongoing debate in the planetary science community.
Earth is rounded into an ellipsoid with a circumference of about 40,000 km. It is the densest planet in the Solar System. Of the four rocky planets, it is the largest and most massive. Earth is about eight light-minutes away from the Sun and orbits it, taking a year (about 365.25 days) to complete one revolution.