anders at aleph.se
Thu Jan 26 00:09:20 UTC 2012
On 25/01/2012 19:45, BillK wrote:
> On Wed, Jan 25, 2012 at 6:10 PM, Anders Sandberg wrote:
>> I wonder if anybody has run a hydrocode on what happens to a terrestrial
>> planet subjected to its sun going supernova? It would be interesting to see
>> if any material is ejected that is not subjected to extreme heating and
>> radiation. ...
> But they can eject whole planets from their system and push some
> planets out to larger orbits. Though those planets still exist, I
> expect they are pretty crisply toasted.
Yes. I found this paper when looking for the answer to my question:
http://arxiv.org/abs/1107.1239 "The Great Escape: How Exoplanets and
Smaller Bodies Desert Dying Stars" - apparently quite a lot of planets
and smaller bodies can escape a system where the star is undergoing mass
loss or supernovas.
Even more intriguing is
"Can a Planetary System Survive a Host Star Supernova Explosion?"
where the abstract (the only thing available, it seems) says:
> Our calculations show that even a small Earth-like planet is not
> destroyed mechanically nor thermally in such an explosion (and larger
> planets are even more stable). Nor is a planet kicked out of its orbit
> due to the momentum of exploding star shell or of due to star's
> radiation pressure. In some cases even a portion of a planetary
> biosphere (deep in planet's crust) can survive.
So there is likely some chance of supernovae seeding space with
thrown-off pieces of rock, or old terrestrials drifting around with
frozen subsurface biospheres. Good news for panspermia.
Future of Humanity Institute
Philosophy Faculty of Oxford University
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