<p>The radiometric dating of <strong>meteorites</strong> tells you when certain radioactive species were incorporated into that body. It is extremely difficult to see how that material could have got there at a later time, so the age you get is the age of formation of that body.</p>

<p>Meteorites do not form in stars. They require considerably cooler conditions, but they also require a certain density to stick together. Those conditions are found in a protoplanetary disk. So you might well ask, well maybe the meteorites were formed around another star and then somehow they have ended up in orbit around our Sun.</p>

<p>This is quite unlikely. Very similar ages have been determined for some tens of meteorites and that age happens to be just a touch older than the oldest rocks that can be found on the Earth and the Moon. There is no big age spread among meteorites. That age also coincides with the age for the Sun deduced from physical models (though this age is less accurate because of some remaining uncertainties in the physics, but it is not hundreds of millions of years out).</p>

<p>The obvious inference is that these meteorites were among the first solid bodies formed in the protoplanetary disk that ultimately formed the Earth and Moon and hence represents a <em>lower limit</em> to the age of the solar system. It depends where you wish to start the clock; the formation of the first solid bodies seems as good a place as any and models for disk formation and evolution suggest that these solid bodies do form within about a million years of the molecular cloud that formed the Sun beginning to collapse.</p>

CC BY-SA 4.0
2018-05-11T12:22:41.323Z
I apologize if my imprecise language is making things more difficult. If my understanding is right lead is the element dated, and it can not be produced by the sun. Do we assume the lead accreted from the protostellar cloud? Is there reason to believe these materials were not clumped together at or near the time they were ejected from another star heavy enough to provide the necessary energy to create these materials?
James McLellan
CC BY-SA 4.0
2018-05-11T16:01:53.113Z
Yes, whichever process formed the lead (eg supernova or neutron star collision), it was a very energetic one. The lead would have been ejected in the form of a plasma and not clumped together but mixed with all the other matter ejected. It was only in the cool and relatively high density found in a protoplanetary disk do you find the right condition for solid lumps of rock containing lead to form.
James K
CC BY-SA 4.0
2018-05-13T18:51:08.447Z
Lead is mostly produced by AGB stars.  The radiometric date is the date in which these were incorporated into a solid body. Also the ages come from several different tracers (and are consistent).
ProfRob
CC BY-SA 4.0
2018-05-10T21:43:00.963Z
2018-05-13T18:54:34.457Z
2018-05-13T18:54:34.457Z
ProfRob
<p>I've read articles that state the age of the solar system has been determined by measuring the amount of decay of isotopes in some meteorite, which has demonstrated that  the lead isotopes in the meteorite have cooled and locked into place some number of years ago.</p>

<p>However, if a yellow sun can not create heavier elements, wouldn't it be correct to say the age of an meteorite dated this way is how long it's been since the asteroid was ejected from a blue or heavier star? The sun may have started burning many years after that.</p>

CC BY-SA 4.0
2018-05-10T21:37:49.893Z
Presumably you mean “since *the matter in* the asteroid was ejected”? The asteroid itself was a product of our current solar system, not a previous supernova.
Chappo Hasn't Forgotten
CC BY-SA 4.0
2018-05-11T11:43:35.597Z
How is that possible? My understanding is that the sun is not massive enough to create heavy elements
James McLellan
CC BY-SA 4.0
2018-05-11T13:16:16.697Z
I believe @Chappo is pointing out that accretion of atoms into meterorite-sized chunks of matter happened as the solar system came into being.
Carl Witthoft
<star><planet><solar-system>
Is the age of the solar system equal to the age of meteorites?
James McLellan
# Is the age of the solar system equal to the age of meteorites?

(Asked by: username_0 on 2018-05-10)

I've read articles that state the age of the solar system has been determined by measuring the amount of decay of isotopes in some meteorite, which has demonstrated that the lead isotopes in the meteorite have cooled and locked into place some number of years ago.

However, if a yellow sun can not create heavier elements, wouldn't it be correct to say the age of an meteorite dated this way is how long it's been since the asteroid was ejected from a blue or heavier star? The sun may have started burning many years after that.

**Tags:** star, planet, solar-system
> **Comments:**
> **username_1**: Presumably you mean “since *the matter in* the asteroid was ejected”? The asteroid itself was a product of our current solar system, not a previous supernova.  
> **username_0**: How is that possible? My understanding is that the sun is not massive enough to create heavy elements  
> **username_2**: I believe @Chappo is pointing out that accretion of atoms into meterorite-sized chunks of matter happened as the solar system came into being.  

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## 1 answers

### Answer by username_3 on 2018-05-10. Score: 4

The radiometric dating of **meteorites** tells you when certain radioactive species were incorporated into that body. It is extremely difficult to see how that material could have got there at a later time, so the age you get is the age of formation of that body.

Meteorites do not form in stars. They require considerably cooler conditions, but they also require a certain density to stick together. Those conditions are found in a protoplanetary disk. So you might well ask, well maybe the meteorites were formed around another star and then somehow they have ended up in orbit around our Sun.

This is quite unlikely. Very similar ages have been determined for some tens of meteorites and that age happens to be just a touch older than the oldest rocks that can be found on the Earth and the Moon. There is no big age spread among meteorites. That age also coincides with the age for the Sun deduced from physical models (though this age is less accurate because of some remaining uncertainties in the physics, but it is not hundreds of millions of years out).

The obvious inference is that these meteorites were among the first solid bodies formed in the protoplanetary disk that ultimately formed the Earth and Moon and hence represents a *lower limit* to the age of the solar system. It depends where you wish to start the clock; the formation of the first solid bodies seems as good a place as any and models for disk formation and evolution suggest that these solid bodies do form within about a million years of the molecular cloud that formed the Sun beginning to collapse.

> **Comments:**
> **username_0**: I apologize if my imprecise language is making things more difficult. If my understanding is right lead is the element dated, and it can not be produced by the sun. Do we assume the lead accreted from the protostellar cloud? Is there reason to believe these materials were not clumped together at or near the time they were ejected from another star heavy enough to provide the necessary energy to create these materials?  
> **username_4**: Yes, whichever process formed the lead (eg supernova or neutron star collision), it was a very energetic one. The lead would have been ejected in the form of a plasma and not clumped together but mixed with all the other matter ejected. It was only in the cool and relatively high density found in a protoplanetary disk do you find the right condition for solid lumps of rock containing lead to form.  
> **username_3**: Lead is mostly produced by AGB stars.  The radiometric date is the date in which these were incorporated into a solid body. Also the ages come from several different tracers (and are consistent).  

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