🚀 go-pugleaf

schumach@convex.com (Richard A. Schumacher) writes:

> TVF is not talking vaguely about collisions for disrupting the parent
> body. He has quite clearly explained that he means "explode", not
> collide. Only the one body is involved. Does anyone have the slightest
> idea how to get a planet to explode?

     That's an interesting question, and I have some speculations about
that myself, based on the synthesis of evidence for the explosion
hypothesis in my coming book.  There are clues, such as the heavy neutron
flux exposure, shock, partial melting, charring, and isotopic anomalies
found in meteorites.  Meteorite evidence (especially from chondrules)
strongly suggests an unspecified high-energy event, definitely not pre-
solar system.  That's why the standard model calls for a nearby supernova
event; but they can't quite get the details to work out.  I think the
relatively enormous implied abundance of Al-26 is one of the chief clues
about what really happened -- unless, of course, that hypothetical
supernova contained at least a solar-mass worth of Al-26.

     But I want to be sure we agree that, even if the answer to your
question is "no," it's not relevant to the issue of how the asteroids
originated.  When insufficient information about starting conditions is
available, theory usually follows observation, not vice versa.  Stars were
first observed to explode, and along came a theory to explain that.  Ten
years ago, when M82 was thought to be a galaxy in the process of exploding,
theoreticians came out of the woodwork to explain that.  But the literature
on planetary explosions consists of just a handful of papers dealing with
boundary conditions for equations of state and such.  The lack of interest
is understandable -- according to prevailing opinion, there are no
applications yet.


and nolan@lpl.arizona.edu (Mike Nolan) writes:

> There are data, such as the existance of families of asteroids with
> relative velocities a few hundred m/s, which suggest that the actual
> behavior is not as the models predict.  It's by no means a solved problem
> (it better not be, it's much of my thesis).

     You gave a nice overview of the problems getting anything into orbit
through collisional processes.  But in the exploded planet hypothesis, the
origin of asteroid families is a solved problem.  When one large asteroid
strikes another, both of their satellite clouds escape into solar orbits
similar to that of their merged parents.  These multiple similar orbits
make up what we call a "family."  [Technical aside: "Jet streams" are
families created so recently that their nodes and perihelia haven't had
time to redistribute fully.  "Families" are older and their velocity
dispersion is higher because of the difference between proper and
osculating elements.  See how easy the explanation becomes when the model
is right?  :-)]

> But no matter what speed the bits leave at, it's still hard to get them
> in orbit.  If they're moving at less than escape velocity, they'll likely
> fall back, faster and they just leave.  The injection burn is hard to
> come by.

     Not only must you introduce angular momentum to get them to orbit, but
you must introduce it at a great-enough distance that the pericenter is
outside the synchronous orbit.  Otherwise tidal forces bring the fragments
down again in short order.

     We are in complete agreement -- you can't get abundant satellites of
asteroids with the standard model.  The exploded planet hypothesis is the
only known way at present.

     Best wishes on your thesis.  -|Tom|-

-- 
Tom Van Flandern / Washington, DC / metares@well.sf.ca.us
Meta Research was founded to foster research into ideas not otherwise
supported because they conflict with mainstream theories in Astronomy.