Zircons

What is most widely accepted today is the giant-impact theory. It proposes that the Moon formed during a collision between the Earth and another small planet, about the size of Mars. The debris from this impact collected in an orbit around Earth to form the Moon.

Discovery suggests exploding star kick-started our sun. Pea-size minerals inside a meteorite are the oldest known material in the solar system, a new study says.

Scientists identify oldest crystal on Earth — 4.4 billion years old

• 1/3. A 4.4-billion-year-old zircon crystal is the oldest material ever found on Earth. (
• 2/3. The Jack Hills zircon is the oldest material ever discovered on Earth. (
• 3/3. Looking down on Jack Hills, where the oldest zircon on Earth was discovered. (

zircons

The oldest zircon dates are 4.36 billion years. Before this study, the oldest dated rocks were from a body of rock known as the Acasta Gneiss in the Northwest Territories, which are 4.03 billion years old.

4.28 billion years

three kinds

It’s firm and hard like other rock, but it’s actually flowing very slowly, about as slowly as your fingernails grow. The outer core is a liquid layer, made mostly of iron and nickel, that moves around the inner core. This motion causes Earth to act like a giant magnet.

Formation. When the solar system settled into its current layout about 4.5 billion years ago, Earth formed when gravity pulled swirling gas and dust in to become the third planet from the Sun. Like its fellow terrestrial planets, Earth has a central core, a rocky mantle and a solid crust.

3.5 billion years

This is expected to occur between 1.5 and 4.5 billion years from now. A high obliquity would probably result in dramatic changes in the climate and may destroy the planet’s habitability.

Earth would flourish. It appears the vast over population and pollution of the world is the result of over thirty millennia of struggle to reach the Moon and determine its nature. If humans went extinct then the state of the earth would be of no consequence to us because we wouldn’t exist.

We could track more asteroids, build better bunkers, improve our disease surveillance programs, reduce our greenhouse gas emissions, encourage non-proliferation of nuclear weapons, and strengthen world institutions in ways that would probably further decrease the risk of human extinction.