First generation stars around 15 billion years ago. They (and their planetary systems) consist of *only* hydrogen and some helium. Chances of life are pretty slim. :-)
Second generation stars formed around 10 billion years ago from areas "seeded" by first generation stars that have gone supernova. So they have heavier elements up to iron (which will be fairly rare).
Life might evolve but it'd be *very* different from life here because of the difference in elemental abundances. Earth would be an environment full of toxic "heavy" metals to those life forms.
Also, if intelligent life evolved, it's had a 5 billion year head start on us. If they are still around, we'd likely be of little interest to them.
Third generation stars (like Sol) are only 5 billion or so years old. They formed from areas seeded by second generation supernovas. They've got elements up to uranium. Iron is not uncommon.
Sol is one of the older third generation stars in the neighborhood. So *we* may be the "older and wiser" civilization. Eep!
The distribution of the various generations in the galaxy affects a lot of things too. The central are of the galaxy is first generation stars. so besides the radiation hazards, the elements for life aren't there.
Other areas of the galaxy are mostly first generation stars as well. This will greatly affect where "desirable" real estate will be found.
ps. I recall *one* SF novel that used this sort of thing. It had a few remaining aliens from second generation stars trying to keep us youngsters from making *serious* mistakes (and not doing so well :-)
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dancing_serpent
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Date: 2020-01-13 11:21 pm (UTC)First generation stars around 15 billion years ago. They (and their planetary systems) consist of *only* hydrogen and some helium. Chances of life are pretty slim. :-)
Second generation stars formed around 10 billion years ago from areas "seeded" by first generation stars that have gone supernova. So they have heavier elements up to iron (which will be fairly rare).
Life might evolve but it'd be *very* different from life here because of the difference in elemental abundances. Earth would be an environment full of toxic "heavy" metals to those life forms.
Also, if intelligent life evolved, it's had a 5 billion year head start on us. If they are still around, we'd likely be of little interest to them.
Third generation stars (like Sol) are only 5 billion or so years old. They formed from areas seeded by second generation supernovas. They've got elements up to uranium. Iron is not uncommon.
Sol is one of the older third generation stars in the neighborhood. So *we* may be the "older and wiser" civilization. Eep!
The distribution of the various generations in the galaxy affects a lot of things too. The central are of the galaxy is first generation stars. so besides the radiation hazards, the elements for life aren't there.
Other areas of the galaxy are mostly first generation stars as well. This will greatly affect where "desirable" real estate will be found.
ps. I recall *one* SF novel that used this sort of thing. It had a few remaining aliens from second generation stars trying to keep us youngsters from making *serious* mistakes (and not doing so well :-)