The earth was formed around 4.5 billion years ago. Gas from volcanoes most likely caused the early atmosphere, but it had no oxygen and would have been toxic to most living things. The Earth would have been very very hot with molten lava because of the volcanoes and frequent collisions with rocks from outer space. One very large collision is thought to have broke a bit of the earth off and formed the Moon! Over a billion years, the planet cooled and liquid formed the oceans but they would have been an ugly brown thick broth. It is thought that the first life forms appeared between 3.8 and 3.5 billion years ago in this broth. Scientists recently recreated this early atmosphere in an airtight glass tube and ran electricity through it and found in the broth, molecules that are similar to a chemical called RNA which is a component of DNA which is what we are all created from. DNA is known as the building blocks of life. Over millions of years those chemical molecules changed and broke apart and joined up until DNA was formed. Once DNA was formed evolution began occurring. Living things were microscopic creatures at first. Photosynthetic life appeared around 2 billion years ago. Photosynthesis is what plants and some other organisms do. They convert CO2 to oxygen. This enriched the atmosphere with oxygen. About 580 million years ago, multicellular life arose.
Biological and geological change has been constantly happening on the planet since the time of its formation. Organisms continuously evolve, taking on new forms or going extinct in response to an ever-changing planet. Eventually humans came along.
First of all I wouId like to congratulate you, Jackylegs, on asking such a profound question! This is one of those questions that has driven scientists to study really hard to try and discover the answers, so maybe you’re on your way to being a scientist yourself!
I agree that Jennifer has answered this question really well for you. When I read it, I actually thought of the Big Bang Theory first (not the TV show). This theory explains how the whole universe began about 13.7 billion years ago (that’s 9.2 billion years ago before our Earth formed).
Our universe is thought to have begun as something really really small, infinitely hot and infinitely dense. When an event called the ‘Big Bang’ happened, our universe suddenly expanded very quickly and then cooled, going from very, very small and very, very hot, to the size and temperature of our current universe.
The universe continues to expand and cool to this day (it’s actually getting faster in its expansion) and we are inside of it! Where did it come from? We don’t know, but scientists have some interesting theories. Why did it appear? We don’t know. BUT, that’s OK because these are the sorts of questions that scientists love to try and answer! Maybe one day you could try and answer your own question…
The earth was formed around 4.5 billion years ago. Gas from volcanoes most likely caused the early atmosphere, but it had no oxygen and would have been toxic to most living things. The Earth would have been very very hot with molten lava because of the volcanoes and frequent collisions with rocks from outer space. One very large collision is thought to have broke a bit of the earth off and formed the Moon! Over a billion years, the planet cooled and liquid formed the oceans but they would have been an ugly brown thick broth. It is thought that the first life forms appeared between 3.8 and 3.5 billion years ago in this broth. Scientists recently recreated this early atmosphere in an airtight glass tube and ran electricity through it and found in the broth, molecules that are similar to a chemical called RNA which is a component of DNA which is what we are all created from. DNA is known as the building blocks of life. Over millions of years those chemical molecules changed and broke apart and joined up until DNA was formed. Once DNA was formed evolution began occurring. Living things were microscopic creatures at first. Photosynthetic life appeared around 2 billion years ago. Photosynthesis is what plants and some other organisms do. They convert CO2 to oxygen. This enriched the atmosphere with oxygen. About 580 million years ago, multicellular life arose.
Biological and geological change has been constantly happening on the planet since the time of its formation. Organisms continuously evolve, taking on new forms or going extinct in response to an ever-changing planet. Eventually humans came along.
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Jennifer has answered this one very well
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Yes, nice one Jennifer
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First of all I wouId like to congratulate you, Jackylegs, on asking such a profound question! This is one of those questions that has driven scientists to study really hard to try and discover the answers, so maybe you’re on your way to being a scientist yourself!
I agree that Jennifer has answered this question really well for you. When I read it, I actually thought of the Big Bang Theory first (not the TV show). This theory explains how the whole universe began about 13.7 billion years ago (that’s 9.2 billion years ago before our Earth formed).
Our universe is thought to have begun as something really really small, infinitely hot and infinitely dense. When an event called the ‘Big Bang’ happened, our universe suddenly expanded very quickly and then cooled, going from very, very small and very, very hot, to the size and temperature of our current universe.
The universe continues to expand and cool to this day (it’s actually getting faster in its expansion) and we are inside of it! Where did it come from? We don’t know, but scientists have some interesting theories. Why did it appear? We don’t know. BUT, that’s OK because these are the sorts of questions that scientists love to try and answer! Maybe one day you could try and answer your own question…
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Great Job Jennifer.
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