July 12, 2007 | David F. Coppedge

The Daily Planet

This entry is not about birds or planes; it’s supernews from the solar system.

  1. Sponge Blob:  Hyperion, an oddball moon of Saturn between Titan and Iapetus, was featured at Jet Propulsion Laboratory last week (see stunning image from Sept. 2005 at the Cassini imaging team website).  Two papers in Nature July 5 analyzed its sponge-like appearance and surface composition.  The moon is so porous, impactors just plow in and compress the material rather than excavate it.  The dark material in the floors of craters resembles reddish material found on the surfaces of Phoebe and Iapetus, suggesting a link.
        The second paper mentioned the possibility of polycyclic aromatic hydrocarbons (PAH) in the dark material, and briefly stated, “When aromatic molecules are embedded in H2O ice and irradiated with ultraviolet light, new molecules of biological interest are created.”  That was enough to send the popular press into a tizzy about “building blocks of life.”  National Geographic asked in bold print, “Saturn ‘Sponge Moon’ Has Ingredients for Life?” even though Hyperion has no atmosphere and PAHs are the like the toxic compounds in tailpipe soot.  Science Daily used the L word four times, embellishing the soot as “hydrocarbons that may indicate more widespread presence in our solar system of basic chemicals necessary for life.”  Ker Than for Space.com admirably avoided all references to life (but spelled Iapetus wrong 3 times).
  2. Constant Comets:  There’s less differentiation in the interiors of comets than thought, reported National Geographic and PhysOrg.  This “contradicts assumptions about the fiery celestial bodies,” and “has prompted astronomers to take issue with a mainstream theory about the impact of ‘space weather’ on these enigmatic wanderers of the Solar System.”  These stories were based on a paper in Nature1 about Comet 73P/Schwassmann-Wachmann 3, a short-period comet that had fragmented, allowing astronomers to analyze its deep interior.
  3. Mars Beachfront Dries Up:  Nature had a news story July 5 lamenting evidence that the thermodynamics of ancient clays argues against a warm, wet period on the red planet caused by a thick carbon dioxide atmosphere.2  “What did cause it remains an enigma,” David Catling said.
  4. Rubble Blarney:  Asteroids appear to be mostly rubble piles.  Science May 18 commented on the surprise from the Japanese Hayubasa mission that the density of asteroid Itokawa is so low, it must be boulders all the way down.3  Better not expect to divert an earth-bound asteroid by blowing it up, therefore.  Erik Asphaug asked whether any asteroids are made of solid, monolithic rock, as previously thought.
        JPL’s Dawn Mission is scheduled for launch in September.  It is slated to visit two of the largest asteroids: Vesta (2011) and Ceres (2015).
  5. Belching Moon:  Evidence for outgassing on the moon (lunar transients) continues to rise.  Scientific American published an article June 26 about these flashes in the pan that have been reported for centuries.  J.R. Minkel wrote that the observed radon gas may arise from “dust stirred up by such emissions—possibly volcanic in origin.”  Often doubted as artifacts of the observer’s imagination, some astronomers are taking them very seriously.  Arlin Crotts (Columbia U) said this is not like UFO studies: “this is real science.  And it’s something people should have done 30 years ago.”
  6. Iron Supplements:  Some geophysicists publishing in Science May 25 pondered the presence of short-lived radioisotopes in some meteorites.4  Things like aluminum-26 and iron-60 burn out too fast to have been part of the original solar nebula, they said.  Though aluminum-26 appears primordial, the iron-60 does not.  Their solution was to have a nearby supernova go off near the solar system during its formation, to seed the planetesimals with the iron-60, which a half-life of 1.5 million years.  The Earth, though, does not have much residue of this material, so they had to make it a special case: “Earth accreted from material distinct from that of any known primitive and/or differentiated meteorites.”
        The European Astrobiology Magazine did a feature story on this subject, called “The Violent Origin of the Solar System.”  The article points out that it is not normal for molecular clouds to collapse into solar systems.  Heat and pressure pushes the material back outward.  They suggest that turbulence in the cloud causes localized clumping that overcomes the gravitational barrier and triggers collapse.  “But what feeds the turbulent energy in molecular clouds?  There are several imaginative scenarios, all of which are hotly debated.”  Supernovas to the rescue, the article continues: not only do they trigger star formation, they seed the gas with heavy elements critical for planets and life.  “A species of radioactive iron known as iron 60 was discovered only two years ago,” it stated.  “This discovery provides new evidence in favour of a supernova explosion in the vicinity of the young solar system.”  In conclusion, Simon Mitton wrote, “Astronomy has much to offer astrobiology in terms of explaining the formation of stars and their planets.  What the astronomers are saying in this case is that our solar system had a violent origin of a kind that is not typical.  That extra dose of iron 60 in meteorites speaks volumes about our cosmic origins.
  7. Hot Wet Jupiters:  The press all caught onto an announcement that the Spitzer Space Telescope detected the spectrum of water vapor around an extrasolar planet.  Don’t expect swimming holes around HD 189733b just yet; the “hot Jupiter,” that zips around its parent star every two days, “is a fiery 1,000 Kelvin (1,340 degrees Fahrenheit) on average.”  The scientific team only suggested that this means other rocky planets in the system might also have water, presumably in a liquid form if located far enough away from the star.  No such planets have been detected yet.  This did not stop the BBC News from using the L word life four times in its writeup.  Most reports, like that on National Geographic, emphasized the word water when “steam” might have been more appropriate.

Briefly noted:  The Mars rovers are trying to ride out a “scary” dust storm that came up suddenly (see Space.com).  A new Mars lander named Phoenix is slated for launch next month, for a landing near the northern ice cap.  And the Cassini spacecraft is ending a year-long series of tight orbits around Saturn with frequent flybys of Titan.  For a detailed look at the upcoming T34 Titan flyby on July 19, download this PDF mission description.  Saturn’s ring spokes are now being seen more frequently.  Evidence for outgassing from Tethys and Dione was reported last month.  New images of Tethys were taken June 27, revealing more about its scar, Ithaca Chasma, that is 3 times as long as Earth’s Grand Canyon.  One of the biggest highlights of this year’s tour comes September 10 when Cassini skims a mere 932 miles above the surface of mysterious yin-yang moon Iapetus.  The Cassini website recently featured a new slide show of 9 highlights from its third year in orbit around Saturn.

1Dello Russo et al, “Compositional homogeneity in the fragmented comet 73P/Schwassmann-Wachmann 3,” Nature 448, 172-175 (12 July 2007) | doi:10.1038/nature05908.
2David C. Catling, “Mars: Ancient fingerprints in the clay,” Nature 448, 31-32 (5 July 2007) | doi:10.1038/448031a.
3Erik Asphaug, “Planetary Science: The Shifting Sands of Asteroids,” Science, 18 May 2007: Vol. 316. no. 5827, pp. 993-994, DOI: 10.1126/science.1141971.
4Bizzarro et al, “Evidence for a Late Supernova Injection of 60Fe into the Protoplanetary Disk,” Science, 25 May 2007: Vol. 316. no. 5828, pp. 1178-1181, DOI: 10.1126/science.1141040.

Planetary exploration is an adventure the whole world can share.  Just beware the marketing claims of certain charlatans who want you to think evolutionists have a complete cosmic package all neatly tied up.  Three things are commonly found in their spiels: (1) they need to insert finely-tuned miracles, like supernova explosions, to get things to work out right, (2) anomalies (like lunar transients) surprise them but never get them to question their assumptions, and (3) the word “organic” (even though it only refers to carbon compounds not necessarily biological) sends them into euphoric visions of life emerging from the dust.  Hyperion’s soot has nothing to do with life, OK?  The first four letters of the moon’s name are appropriate.  Turn off the Darwin commercials and enjoy the ride.

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Categories: Physics, Solar System

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