Comment Re:Planets (Score 1) 145
"It just means this specific matter arrived on earth after the planet was already pretty well formed."
The material from which the earth formed likely contained such material as well . It didn't necessarily have to rain from the sky. Some of that material may have originated on what are now non-existent, i.e. destroyed, planets. All the metals on the earth are a result of previous generations of stars, so why couldn't at least some of this type of material not have been included in the "mix" as well? Bacteria have been found deep inside rocks on earth so why should something similar not have been in the rocks and planetesimals from which the earth formed?
The material from which the earth formed likely contained such material as well . It didn't necessarily have to rain from the sky. Some of that material may have originated on what are now non-existent, i.e. destroyed, planets. All the metals on the earth are a result of previous generations of stars, so why couldn't at least some of this type of material not have been included in the "mix" as well? Bacteria have been found deep inside rocks on earth so why should something similar not have been in the rocks and planetesimals from which the earth formed?