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The Near-Earth Asteroid Rendezvous (NEAR) spacecraft will arrive at
Earth-approaching asteroid Eros next month, in early January 1999. As of
this writing, no mainstream astronomer has been willing to accept a wager
against this prediction, although none expect it to be correct either.
Preamble: The exploded planet hypothesis (as described in Dark Matter,
Missing Planets and New Comets) implies that all asteroids and comets are
formed as debris clouds during the explosion of planet or moon-sized bodies
at astronomically recent epochs. Only those asteroids involved in collisions
will have their orbiting debris removed, forming families (in the case of
long-ago collisions) or jet streams (in the case of recent collisions). For
most "loner" asteroids and comets, the original debris clouds around the
primary nucleus should still be intact. The debris would consist of material
of all sizes from dust to near-primary-nucleus size. Normal evolution of
such debris clouds under tidal forces would tend to concentrate much of the
debris into the orbital plane, and to collect some of that planar debris in
an equatorial ring at the synchronous satellite orbit location (typically
1-2 radii above the asteroid surface). Debris inside the synchronous orbit
should be cleared out by tidal forces and mostly found now lying on the
surface of the primary asteroid. These would commonly be seen at places of
maximum radius on the primary nucleus, and often accompanied by roll marks
because of their gentle, tangential impacts.
As this model pertains to the Eros encounter, the NEAR spacecraft will enter
orbit around Eros in January 1999. The exploded planet hypothesis makes a
specific prediction for the encounter that is unlikely to be true if the
hypothesis is false. This assumes only that there is no relevant equipment
malfunction or other mission failure, such as failure to achieve orbit
around Eros. In particular, the model implies a considerable hazard for a
spacecraft flying too close to an asteroid nucleus. Any "sudden, unexplained
loss of spacecraft signal" while the spacecraft is flying deep inside the
gravitational sphere of influence of Eros would be fully in accord with
expectations of this model. Such an event cannot be declared a failure of
this prediction if it happens before the spacecraft has had the opportunity
to photograph at least the complete synchronous orbit space near Eros from
sufficiently close range to be able to see small moons.
Specific Prediction: The NEAR spacecraft will discover three or more
satellites 1-meter in size or larger in stable orbits around the Eros
primary nucleus.
Postamble: We really expect many satellites ranging up to a few kilometers
in size, a ring of material in the synchronous orbit, and a concentration of
small particles in the orbital plane. But one must be specific in a
prediction; and three or more satellites a meter or more in size should
distinguish the exploded planet hypothesis (eph) prediction from the
standard model because satellites arising from collisional processes are
exceedingly rare. (Collisions normally cannot place ejecta in orbit because
any such orbit intersects the crater from which it formed. Even if a low
orbit were achieved, it would be inside the synchronous orbit, so tidal
forces would bring it down again in a relatively short time.) Models other
than the eph that predict satellites require special, rare circumstances,
and seldom produce asteroids more complex than binary. In the eph,
satellites are expected to be numerous and commonplace because every such
body originates with dozens to thousands, and collisions have not had enough
time since that origin to strip away most such debris clouds from "loner"
(non-family) asteroids. With regard to the environment surrounding primary
asteroid nuclei, what we find at Eros will therefore probably be
representative of most "loner" asteroids -- either rich in satellites or for
the most part devoid of them.
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