Earth and Moon formed '120million years later than previously thought'. The Earth and the Moon were both formed after a massive collision between two planets far later than previously thought, according to new research.
The planets in the solar system were created by collisions between small dwarf planets orbiting the newborn sun.
In the collisions the small planets melted together and formed larger planets.
Until now it was thought the Earth and the Moon were formed when the solar system was just 30 million years old or around 4,537 million years ago.
But new research suggests that they both may have been formed much later - perhaps up to 150 million years after the formation of the solar system.
The Earth and Moon are the result of a gigantic collision between two planets the size of Mars and Venus.
The collision took place in less than 24 hours and the temperature of the Earth was so high (7000ยบ C), that both rock and metal melted.
The two planets collided at a time when both had a core of metal (iron) and a surrounding mantle of silicates (rock).
The age of the Earth and Moon can be dated by examining the presence of certain elements in the Earth's mantle.
Hafnium-182 is a radioactive substance, which decays and is converted into the isotope tungsten-182.
Scientists have worked out the age of the Earth by measuring the levels of this tungsten isotope in its surface.
'We have determined the ages of the Earth and the Moon using tungsten isotopes, which can reveal whether the iron cores and their stone surfaces have been mixed together during the collision', explains the University of Copenhagen's Tais W. Dahl.
Until recently it was believed that the rock and iron mixed completely during the planet formation and so concluded, based on analysis of rocks on the Earth's surface, that it was formed when the solar system was 30 million years old.
But new research by the university's Niels Bohr Institute indicates that the collision which formed the Earth took place after nearly all of the hafnium had decayed completely into tungsten.
It takes 50-60 million years for all hafnium to decay and be converted into tungsten, and during the collision nearly all of the metal sank into the Earth's core.
'We have studied to what degree metal and rock mix together during the planet-forming collision,' said Dahl.
'Using dynamic model calculations of the turbulent mixing of the liquid rock and iron masses we have found that tungsten isotopes from the Earth's early formation remain in the rocky mantle.'
The research results have been published in the scientific journal, Earth and Planetary Science Letters. ( dailymail.co.uk )
The planets in the solar system were created by collisions between small dwarf planets orbiting the newborn sun.
In the collisions the small planets melted together and formed larger planets.
Until now it was thought the Earth and the Moon were formed when the solar system was just 30 million years old or around 4,537 million years ago.
But new research suggests that they both may have been formed much later - perhaps up to 150 million years after the formation of the solar system.
The full moon rises above Earth in a photo taken from the space station. New research suggest both formed far later than previously thought
The Earth and Moon are the result of a gigantic collision between two planets the size of Mars and Venus.
The collision took place in less than 24 hours and the temperature of the Earth was so high (7000ยบ C), that both rock and metal melted.
The two planets collided at a time when both had a core of metal (iron) and a surrounding mantle of silicates (rock).
The age of the Earth and Moon can be dated by examining the presence of certain elements in the Earth's mantle.
Hafnium-182 is a radioactive substance, which decays and is converted into the isotope tungsten-182.
Scientists have worked out the age of the Earth by measuring the levels of this tungsten isotope in its surface.
'We have determined the ages of the Earth and the Moon using tungsten isotopes, which can reveal whether the iron cores and their stone surfaces have been mixed together during the collision', explains the University of Copenhagen's Tais W. Dahl.
Until recently it was believed that the rock and iron mixed completely during the planet formation and so concluded, based on analysis of rocks on the Earth's surface, that it was formed when the solar system was 30 million years old.
But new research by the university's Niels Bohr Institute indicates that the collision which formed the Earth took place after nearly all of the hafnium had decayed completely into tungsten.
It takes 50-60 million years for all hafnium to decay and be converted into tungsten, and during the collision nearly all of the metal sank into the Earth's core.
'We have studied to what degree metal and rock mix together during the planet-forming collision,' said Dahl.
'Using dynamic model calculations of the turbulent mixing of the liquid rock and iron masses we have found that tungsten isotopes from the Earth's early formation remain in the rocky mantle.'
The research results have been published in the scientific journal, Earth and Planetary Science Letters. ( dailymail.co.uk )
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