2012-02-03 06:14 am (UTC)
This kind of solar system model, of which there used to be
one (rather smaller!) on the local university campus here,
might lend itself wonderfully to refinements using Pluto as
the gateway to expanded focus on congregate or "belt"
planets as well as the eight "dominant" planets. Certainly
Ceres and Vesta should be included as a dwarf and subdwarf
planet in the Main Asteroid Belt, the latter with a
terrestrial differentiation and active geological history.
Beyond Pluto and the Kuiper Belt, we have Eris as a
Scattered Disk Object, and the mysterious Sedna as possibly
either an "Extended Scattered Disk Object," a representative
of the "Inner Oort Cloud," or something else. Of course, in
a model on a scale of miles, including Eris and especially
Sedna might expand things by a factor of two or so -- maybe
with a sign explaining that Sedna's orbit will take it out
to around 960 AU, with a period of around 11,400 years!
While that's an extra stretch of the imagination, it has the
advantage of making interstellar distances maybe a bit less
incomprehensible, or at least a bit more in context, while
at the same time underscoring their hugeness.
For example, in a model where the Sun-Pluto distance is
about 5 miles, there might be sign for Sedna about 10 miles
out: "Sedna's furthest distance from the Sun (960 AU) would
take us out about 120 miles on this scale; but the distance
to Proxima Centauri, the next star (271,000 AU), over 33,000
miles -- further than a global circumnavigation, or a trip
in space to a geosynchronous orbit!"
An understanding that there is an amazing diversity of
planets -- dominant planets, congregate or belt planets;
planets in hydrostatic equilibrium or with a history of
differentiation due to self-gravity, and smaller
microplanets of various shapes which are also an integral
part of the ecology of our Solar System and others --
doesn't prevent us from focusing on specific landmarks or
details of interest. At the same, it has the advantage of
opening the door to knowledge while embracing rather than
fearing or trying to "tame" the real ambiguities and
complexities of our universe and our attempts to
conceptualize it as our knowledge increases.