Thursday, January 22, 2015

Geosonnet 25

The Earth once had a frozen shell of ice
encasing oceans, land, from pole to pole.
The mystery: what process could suffice
To kiss Snow White, rouse cryogenic soul.
One theory says volcanic CO2
Would slowly warm the Earth until the thaw
As ice breaks up, the air and water brew:
Carbonic acid forms: paleo-spa.
The isotopes of boron measure bases.
Post-glacial carbonates record the change
As acid forms, the calcium replaces
Hydronium, a weathering exchange.
   Across the world, the acid came and went;
   A single ocean-atmosphere event.

Geology 42 1103

Saturday, January 10, 2015

Geosonnet 24

The linear progressions we assume
sphericalize our precious holey cows
the certainty simplicities presume
breed dreamt-up facts we dutifully espouse
Repeated careful data overthrow
and phosphorus impurities reveal
Olivine is white-hot Devil's snow
A closet skeleton time can't anneal.
This phoenix from volcano is reborn
Forgotten stories texture can unearth
abandon simple models, do not mourn
Complexity's explanatory worth.
   The simple models woo, but cannot stay.
   Eventually the facts get in the way.

Geology 42 867

Wednesday, December 31, 2014

Blog hiatus

So, I broke my ankle back in October, and after surgery and as a result, work and parenting has sucked up pretty much all of my time. And the geosonnet backlog has finally run its course. Also, although the "moon boot" is marketed as bing for walking, it doesn't seem to be particularly good for walking on lava. I'm guessing it was designed by a non-geologist.

Wednesday, December 17, 2014

Geosonnet 23

On Mars and Venus air is CO two,
While on the Earth it is but a trace gas.
Our rocks and water scrub the gas into
The stable carbonates, which won’t degas.
In torrid climates, weathering is fast.
Cold rivers transport unreacted grains
Fluvial temperature in eons past
Can be deduced with XRF and brains.
The elements in sediments explain
An early Permian heats up and thaws.
Jokulhlaups warm up more than the jungle rain
Digesting rocks chewed up by glacial jaws.
   This weathering drew down the CO two
   But not enough for ice to grow anew.


Wednesday, December 10, 2014

Geosonnet 22

From flood basalt hot sulfur will exhale,
Across the dying planet, smog bank draped
The genie left the bottle, empty grail,
No evidence what long ago escaped.
The lava flows forget what they degassed
A fleeting daydream, lost with time’s progress
But though a hundred million years have passed
The clinopyroxene preserves the S.
Partitioning experiments defined!
A synchrotron or ion probe can see
The sulfur clouds to which we once were blind
Are quantified now, analytically.
   Sulfurous magma wrecked the biosphere
   While clean eruptions let life persevere.

Wednesday, December 03, 2014

Geosonnet 21

Our early atmosphere was quite anoxic
‘till early algae terraformed the Earth.
One grand event, replacing gasses toxic?
Or did O oscillate since life’s first birth?
Did evolution make fate manifest?
Inexorable progress of the gene?
Or was the early oxygen repressed?
Methanogenic dominance was seen.
These visions of our past yearn to be fact.
Hypotheses distinct yet plausible.
The dawn of life’s mysterious, abstract,
Lest ancient rocks reveal what’s causable.
   Archean soil lets us know the way.
   Oxygen came, but then it went away.

Wednesday, November 26, 2014

Geosonnet 20

The cratered lunar face preserves the song
Of bolide roller derbies eons past
But while the cold dead moon remembers long
The rains of Earth reshape the surface fast.
Did impacts peak four billion years ago?
Or taper off through geologic time?
Archean rocks are analysed to know
micaceous balls were hot glass in their prime.
This impact melt was blasted into space
By comets larger than the dino's doom.
Thus diminution models must replace
The cut-off LHB has us presume.
   Can cratering effect how cratons grow?
   Tectonic orogens changed status quo.

Geology 42 747

Thursday, November 20, 2014

The wrong kind of Bang

In science education and popularization, there is a delicate balance that must be struck between overcomplicating and oversimplifying. Insufficient simplification can result in overly obtuse deviation into secondary details, which confuse and distract the readers and derail the flow of the prose.  Excess simplification can be wrong.  And this is where the Medium article by Ethan Siegel of “Starts with a Bang” fame has ended up. 

Dr. Siegel argues that the recent Philae comet lander would have more successful if it had been powered with a 238Pu RTG device instead of solar panels.  However, his simplified argument ignores the reality of 238Pu fuel production, the definition of “we”, and the nature of comets.

238Pu is a byproduct of the nuclear arms race between the USA and the USSR. It is created by neutron activation of 237Np, which in turn is a byproduct of 239Pu production for nuclear weapons. With the nuclear arms deals of the 1980’s the superpowers stopped building nuclear weapons by the tens of thousands, and the cheap source of 237Np disappeared.  The USA stopped 238Pu production in 1988, all subsequent material has come from Russia, which has almost depleted its stockpiles.

This brings us to the definition of “we”.  As the battleground over which the USA and the USSR fought, Europe never developed its own mass nuclear warhead production facilities; the UK and French arms supplies are only a tiny fraction of the size of the 20th century superpowers.  As a result, Europe has never had its own large scale 238Pu production facilities. 

Philae was a European mission, not a USA or Russian one, so the ESA (European Space Agency) did not have access to 238Pu needed for RTG production.  NASA (USA) and the ESA (Europe) are separate space exploration entities, a point that was very unclear from this article’s frequent discussion of NASA and Philae.

Finally, RTG’s are hot, and comets are cold. The Philae lander was a very risky mission- there was a significant chance that it would not succeed at all, and in the end the lander ended up bounding off an unexpectedly hard surface several times before ending up on its side in a crater.

Comets, by definition, evaporate at low temperatures- this one is jetting out gasses despite being way out beyond the asteroid belt. So landing a heat-producing source on it, especially on a lander that ended up tipping over, would end up in a situation where the lander could drastically alter the local environment of the comet through thermal contact.  The whole point of the mission is to sample a comet in as pristine condition as possible, so potentially cooking the comet due to a landing mishap is not really a sensible design choice.

Dr. Siegel is correct that 238Pu is crucial for missions that operate beyond the orbit of Jupiter.  But the fuel used on previous missions was subsidized by the nuclear arms race.  It, and all the wondrous outer solar system exploration it allows, was an unintended byproduct of Mutually Assured Destruction, and the tens of thousands of nuclear weapons that policy produced.  Since the arms race ended, production of this isotope for the sole purpose of planetary exploration has been deemed too expensive to pursue by all the world’s governments.  Until we collectively decide to blow ourselves up again, this barrier to outer solar system exploration will continue.