March 25, 2008 | David F. Coppedge

March Moon Madness

Moons of our planetary system are supposed to behave themselves.  They were expected to just quietly orbit their host planets like nice, cold, frozen, inactive chunks of rock and ice.  It seems like whenever we get a close look at them, they are madly at work destroying theories – just like their planets have been wont to do.

  1. Io, Io, It’s Off to Work I Go:  “The results are surprising because no theory predicted upstream spots.”  Belgian researcher Bertrand Bonford was commenting on a press release from American Geophysical Union (AGU) about the volcanic moon Io, and how its eruptions create auroral spots on Jupiter.  “The finding of the leading spot puts all the previous models of the Io footprint into question,” the article said.
  2. Tethys Ocean:  The “surprisingly ordinary” moon Tethys at Saturn may have, or may have had, an underground ocean, according to National Geographic News.  The energy required to create the monstrous rift called Ithaca Chasma must have melted the ice below.  Where did the heat come from?  Since Tethys is largely ice, there would not have been radioactive elements sufficient to produce internal heat.  This leaves tidal flexing to create the rift – but only if there was liquid underneath.
        The thought of water quickly led to thoughts of life.  A Cassini scientist told NGN, “This makes the exploration of icy satellites and their interiors even more important to understanding possible habitats for life in our solar system” and for how common life is in the universe.
  3. Do you want your Mars with salt?  Sodium chloride – good old table salt – may be common on Mars, said the BBC News and EurekAlert.  Because the salt may have become deposited in channels and lakes, some scientists immediately visualized the salt as a preservative for life.  Salt is a double-edged sword, however: “Water is the first sign that an environment might have been habitable, but waters that precipitate table salt on Mars would have been much saltier than any waters known to support microbial populations on Earth,” said Andrew Knoll of Harvard.  Salt is also a poison to organic soup (09/17/2002).
  4. Titan clash:  Titan isn’t rotating like scientists expected.  When they went to focus on a spot identified from a previous orbit, it was 19 miles off.  The only way they can explain it is by modeling an ocean under the ice, according to a paper in Science.1  If the crust is decoupled from the interior by floating on an ocean, it also means that Titan’s zonal winds can alter the rotation of the whole moon.  See explanation by The Planetary Society and press release from JPL.
        The ocean-and-wind hypothesis is only a partial answer.  Christophe Sotin and Gabriel Tobie, writing in the same issue of Science,2 said, “However, the observations and model predictions do not correlate very well.”  Some are proposing a periodic wobble in the spin, or a large impact that might have sped up the rotation.  No impact basin large enough to record such an event has been found.  “There’s a fundamental difficulty with Titan global circulation models right now — all of them,” said lead author Ralph Lorenz, “–which is that they predict that the predominant winds at low latitudes near the surface would be easterly, from east to west.  Yet all the sand dunes point in exactly the opposite direction.  There’s something we do not understand about Titan’s circulation.”

Back on earth, scientists are also scrambling to explain the origin of the home planet.  Science Daily, PhysOrg and National Geographic News all reported that a “new study is challenging the long-standing notion that the whole solar system formed from the same raw materials.”  Isotopes in meteorites don’t match those on earth.  To get around this problem, scientists are having to imagine that materials in the solar disk that supposedly gave birth to the planets got sorted somehow.
    In addition, a news item in Nature News about the Genesis solar-wind collection experiment “raises more questions.”  The finding that “the Sun is relatively richer than Earth in oxygen-16, the most common oxygen isotope, contradicts the conventional wisdom that Earth has the same oxygen isotope composition as the Sun” the article said. “Everybody would have bet that the Sun had the same composition as Earth and the meteorites,” a French cosmochemist remarked.  “In fact, Earth is not like the Sun.”  Scientists are scrambling to model what process might have “sucked out oxygen-16 while the gas of the proto-Solar System condensed into solid grains that coalesced into the planets.”  If so, the article said, it would have had to happen early on.
Footnote:  We’re still waiting for word about the Enceladus flyby results from March 12.  Expect more surprises.  Whatever is found will have to comport with findings of Roberts and Nimmo in the April Icarus.3  Their calculations show that neither radioactive decay or tidal forcing are adequate to maintain a liquid ocean under the crust for more than 30 million years (6% of the assumed age).  Heat is removed from the surface faster than it can be generated in the core, and tidal heating is far too low at the present orbit.  The only way they could rescue a long-lived ocean was to propose an ad-hoc scenario: perhaps the obliquity of Enceladus is pumped up from time to time.  “A transient ocean could exist beneath the ice shell today as a remnant of an earlier epoch of higher heating,” they said.  Such a phenomenon is beyond observation.


1.  Lorenz et al, “Titan’s Rotation Reveals an Internal Ocean and Changing Zonal Winds,” Science, 21 March 2008: Vol. 319. no. 5870, pp. 1649-1651, DOI: 10.1126/science.1151639.
2.  Sotin and Tobie, “Titan’s Hidden Ocean,” Science, 21 March 2008: Vol. 319. no. 5870, pp. 1629-1630, DOI: 10.1126/science.1155964.
3.  James H. Roberts and Francis Nimmo, “Tidal heating and the long-term stability of a subsurface ocean on Enceladus,” Icarus, Volume 194, Issue 2, April 2008, Pages 675-689, doi:10.1016/j.icarus.2007.11.010.

Science marches on – sometimes in disciplined ranks, sometimes in scatter formation.  The latter occurs when observation bombs drop in on theory playgrounds.
    Remember, the consensus theories that have been blown away by new discoveries were textbook orthodoxy a few years ago.  Only a devout logical positivist would think this could not happen to today’s accepted ideas.  Just wait.
    Evidence does not exist in isolation.  To make sense, it must be incorporated into one’s web of belief by a number of auxiliary hypotheses and assumptions.  Planetary scientists interpret what Ithaca Chasma, Titan’s rotation and Earth’s oxygen-16 ratios mean through the filter of assumptions and auxiliary hypotheses that are rarely considered or questioned independently.
    One of their most sacred assumptions is the A.S.S. (age of the solar system).  The accepted value of 4.5 billion years is written in their genes.  All evidence is viewed within this major structural component of their web of belief.  The web itself stretches and distorts as new evidence bombards it, but it would take a mighty big impact to break it.
    Too much is at stake for secular planetologists, bent on finding life and evolution at every water hole, to allow that to happen.  Like predatory spiders, they snag the evidence, wrap it in theories spun out of their own selves, and suck the juice out of it to feed themselves and their young.  The dried up hulk that once contained structure, organs and connective tissue is discarded to blow away in the wind.
    If you love and respect science, make like a bee instead.  Get busy and gather nature’s nectar far and wide.  Digest it carefully.  Transform it into something sweet to benefit others – something that will nourish the heart and bring delight to the eyes.  (Thanks to Francis Bacon for the metaphor.)

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