ESG7@DFVLROP1.BITNET (11/18/86)
My assertion that the TAU may be a boondoggle induced response from many
readers. Steve Willner correctly states that the prime mission for the
TAU is to measure stellar distances by parallax. Accuracy through this
method can be achieved through either having a large and accurately
known base leg with a telescope of modest resolution, or a short and
even more accurately known base leg with a high resolution telescope.
It seems to me that limited space and astrophysics funds are better
served with a high resolution telescope which can do something other
than astrometry. Also the comparison of TAU with Voyager is a specious
argument. It is true that the Voyagers 1 & 2 and Pioneers 10 & 11 are
going "nowhere". However in their endless journey they did pass
some extremely interesting places, i.e. Jupiter, Saturn, Uranus and
(hopefully) Neptune. It's my understanding that TAU goes directly into
interstellar space. If the planetary program of JPL and NASA Ames were
adequately funded I wouldn't raise a peep about TAU. However when the
government won't even fund a lunar polar orbiter it seems ludicrous to
study something with as bad of a science-vs-cost tradeoff as the TAU.
Also on my admittedly crazy idea about Pluto being a rogue planet, Steve
brought in some misconceptions. Pluto's orbit **does** intersect with
Neptune's orbit along the line of nodes in Neptune's orbital plane.
During this month Pluto has an inclination of 17.1362 degrees to the
eciliptic while Neptune has the much more nomial inclination of 1.7696
degrees. Pluto's perihelion is within Neptune's orbit. One would
expect Pluto to have a highly inclined orbit if it was a rogue planet
that was captured through a near miss with Neptune's Triton. I should
emphasize that this crazy theory of mine is **not** "respectable
science". Main stream views on Pluto reject a Neptune connection
because Pluto has a resonant orbit with Neptune. However the
gravitational interactions between Uranus, Neptune and Pluto are very
strong. Take a look at the longitude of perihelion for Neptune and
you'll be amazed by how much it varies. Long term computer
projections are impossible because round-off error will invalidate any
result. We don't even have accurate mass values for Pluto, so this
subject is wide open to speculation. However there is circumstantial
evidence supporting my crazy idea. Pluto is a double planet. It has a
large moon named Charon. One would expect Pluto to be broken up
by tidal forces when it passed Triton. Triton is larger in size than
Pluto. Therefore it could have provided the necessary kinetic energy
sink to capture Pluto. Triton has an absolutely wacky orbit that is
retrograde at 159.0 degrees to Neptune's equator and is remarkably close
to the planet's surface. Neptune's second moon Nereid has the highest
eccentricity of any moon tabulated in the 1986 Ephemeris and is also
highly inclined. The crazy orbits of Pluto, Nereid and Triton are
evidence that something strange has happened. If Pluto was a rogue
planet its scientific impact would be incalculable. For this
reason I think a Pluto orbiter is a mission worth considering.
Gary Allen