0
The oldest rocks from space are dated back to about 4.5 billion years ago, so this is around when our planet would have formed. The entire Solar System (which includes the Earth) arose when a giant cloud of gas and dust called a nebula began to collapse under its own gravity. This probably happened when, about five billion years ago, a nearby star exploded in a supernova, releasing a shockwave that caused the cloud to contract. Most of the gas gathered in the center to form the Sun, while the rest flattened out into a spinning disk.
The heavier, metallic elements existed closer to the Sun and would form the terrestrial planets. Through gravity, dust particles within the protoplanetary disk began to stick together, growing into pebbles, then boulders, then planetesimals. These chunks of rock collided with one another and clumped together to form larger and larger bodies. This is called accretion: when an object grows in size and mass by gravitationally collecting the material around it. Slowly, over millions of years, Earth formed by this process.
Our planet started out as a hot mass of scorched rock. Volcanic outgassing created the early atmosphere, but it contained almost no oxygen and would have been toxic to humans and most modern life. Much of the Earth was still molten because of extreme volcanism and frequent collisions with other bodies. One very big collision is thought to have been responsible for creating the Moon and tilting the Earth at an angle. Over time, such cosmic bombardments ceased, allowing our planet to cool and form a solid crust. Water that was brought here by comets and asteroids condensed into clouds and the oceans took shape. Earth was finally hospitable to life, and the earliest forms that arose enriched the atmosphere with oxygen.
See the links below for more information.
Earth was formed by collisions within the giant disc-shaped cloud of material. Gravity gathered the dust and gas together into clumps.
Wiki User
∙ 8y ago
Wiki User
∙ 9y agoThe most widely accepted astronomical model of the Earth's formation asserts the planet coalesced gravitationally out the the protoplantary disk - a somewhat flat rotating region of gas and dust resulting from the collapse of a large molecular cloud - from which our Sun and the other planets formed, about 4.6 billion years ago. Formation of Earth itself is thought to have taken about 20 million years or so. Note that because of processes associated with erosion, weather, biological effects, volcanism and other forms of gelogical renewal (see also plate tectonics) the Earth is not quite as obviously cratered as other planets.. so in a sense, the surface continues to re-form.
Add your answer:
Earn +20 pts
What observations are needed to tell whether an Earth-like planet is geologically alive or dead?
images and spectra of the planet
What if there was no magma in the Earth composition?
Then, Earth would have been geologically dead.
When will Earth become geologically inactive?
in aprox 2.5 billion years due to the solidification of earth molten core, unlike mars who's core has already solidifyed resulting in the dead planet we see today
How far form the earth is your planet?
Er ... which planet exactly do you think that we come from? As far as science can discover, Earth IS the only planet with life on it, so you're asking how far Earth is from Earth.
What is the next planet out form the sun after earth?
mars
Why earth is active?
The Earth is geologically active due to the convection of heat from the planet's interior.
What observations are needed to tell whether an Earth-like planet is geologically alive or dead?
images and spectra of the planet
What does saying a planet is geologically active mean?
It describes the ongoing changes to the surfaces of terrestrial worlds. This is because terrestrial surfaces change over time. The moon and mercury are considered geologically dead because their surfaces have remained the same for billions of years.
Which of the terrestrial planets including the moon are considered to still be geologically active?
Earth is the only geologically active planet among the terrestrial planets. There are some geologically active moons in orbit around the gas giants. Enceladus is quite an interesting moon of Saturn.
Do bigger planet become geologically dead sooner than small planets?
No. Smaller planets become geologically dead sooner. A larger planet has a larger volume and thus a larger heat reservoir than a smaller planet and so can remain geologically active for longer.
Is the moon an active planet?
The Moon is not a planet, it, as the name suggest, is a moon.It is not geologically active anymore.
Does Mercury have landforms?
Mercury has no atmosphere, and its surface is heavily cratered much like Earth's moon. It is estimated that the planet has been geologically dormant for a few billion years.
What if there was no magma in the Earth composition?
Then, Earth would have been geologically dead.
When will Earth become geologically inactive?
in aprox 2.5 billion years due to the solidification of earth molten core, unlike mars who's core has already solidifyed resulting in the dead planet we see today
Why is the planet earth special in your solar system?
It is the only planet that has life form on it.
How far form the earth is your planet?
Er ... which planet exactly do you think that we come from? As far as science can discover, Earth IS the only planet with life on it, so you're asking how far Earth is from Earth.
What is the next planet out form the sun after earth?
mars
