-Poul Anderson, "A Tragedy of Errors" IN Anderson, Flandry's Legacy (Riverdale, NY, 2012), pp. 455-540 AT p. 530.
This is yet another Andersonian moment of realization. (See here.) Yasmin's calculations will solve the mysteries of the Nikean environment.
We learn some interesting facts.
"'...any star is something like 98 per cent hydrogen and helium.'"
-op.cit., p. 532.
A planetary core originates because the heavier elements move to the center. Vulcanism, tectonism and radioactivity heat mineral compounds, forcing out gas and thus generating an atmosphere on the smaller planets that have not been able to retain their original hydrogen.
On still smaller planets, like Mars or Nike, the process is slower. Iron, before moving to the center, combines with and reddens surface rocks. Nike, with only half a Terrestrial gravity, has formed a core and thus an atmosphere only in its old age. Tom had thought that Mars-type planets with little air had lost most of their atmospheres, not that they had not formed them yet. That Nike and its star are old, not young, will be significant.
OK. More tomorrow.
1 comment:
Kaor, Paul!
That has implications for our Solar System as well! A billion years from now Mars might have undergone a process like that seen on Nike and again have liquid water (as we know Mars once had, long ago) and an atmosphere humans can breathe.
By then, of course, Earth might well had become uninhabitable due to the Sun being hotter (as we see in the later parts of GENESIS). And if the human race still exists, people will need to move from Earth to Mars.
Sean
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