Mars, Europa & Titan… Hopes for Life

The old SF Solar System had native alien races on just about every body. A prime example is Edmond Hamilton’s “Captain Future” series which featured human races on most moons and all the planets – we were all related by common descent from interstellar travellers from Deneb.

By 1960 those hopes were largely dashed by advances in spectroscopy and radio telescopes – even the most ‘hospitable’ planet, Mars, seemed bare of anything but scabby lichens.

By 1976 – in the wake of “Viking” – even lichens seemed a long shot.

But Mars didn’t wait for us to go visit to get rock samples. Billennia ago bits of Mars were blasted into space and ever since they’ve rained down as the occasional meteorite. In 1996 the Antarctic discovered meteorite, ALH 84001, became famous because microscopic traces looked like bacteria and its chemistry indicated it would’ve been palatable to life at some point in time past. Since then the argument for, and against, this claim has oscillated back and forth. Now new analysis has revived the ‘for case’…

Fresh claim for fossil life in Mars rock

…so who knows? But not really SF material, chiefly because life is probably common between the two planets anyway, due to the meteorite trading that occurs with every big impact. Mars life, as interesting as it will be, is in all likelihood akin to Earth-life.

Further afield are two more interesting prospects for “life as we don’t know it”, Europa and Titan. Titan is in the news again because of the discovery that acetylene is far more abundant in its methane lakes than anyone first imagined, up to 1% in solution…

Icy moon’s lakes brim with hearty soup for life

…which is great news for acetylene-powered life. But I don’t expect such life to be visible without a microscope either. Or rather individually I don’t expect to see it. However bacterial colonies and their traces can be large and colourful… something for a Titan rover to look out for around the lakes.

“I think the results are very exciting and further support the possibility for life on Titan,” says Dirk Schulze-Makuch of Washington State University in Pullman, one of the scientists who proposed the possibility of acetylene-eating life in 2005. “Titan should be one of the two top targets for future astrobiology missions, the other being Mars.”

Dirk’s webpage is here.

If we want ‘alien fish’ then we need an oxygenated ocean. Europa could have a complex biosphere because it probably has just such an oxygen-rich environment. Richard Greenberg has been studying Europa for some time and believes it provides a huge variety of habitats…

Thin Ice Opens up Opportunities for Life on Europa

…the tidal flexing of the ice shell means a flow towards the surface and away on a daily basis, keeping things stirred up and interesting for any life. Europa is also bathed in radiation from Jupiter’s magnetosphere which produces oxidants in its icy shell, which in turn get buried and drawn down into the ocean below…

Europa’s Oxygenated Ocean… Discovery News

…so the situation isn’t so hopeless in our Solar System as it once seemed. There’s enough oxygen to sustain about 3 million tons of sea-life. Doesn’t sound like much, but it’s nothing to sneeze at. There really might be fish – alien, unearthly ones – swimming beneath the crazed ice-shell of Europa.

Pluto, Charon and Cryovolcanism

Pluto
Pluto is just a large Dwarf Planet or Trans-Neptunian Object, like several others out in the Solar System’s ragged Inner Edge.

Pluto Surface

The atmosphere is probably an equilibrium mix of nitrogen and methane that have sublimed off the ices that cover the surface. A few kilometres up – about one scale height – the temperature inverts and rises to about 100 K, remaining pretty much isothermal all the way out to its solar windy exosphere.

Charon view

Charon shows no sign of the N2 or CH4 ices that colour Pluto. It’s a dirty ice surface, darkened by cosmic rays over billennia… except, oddly, it shows signs of water-ice floes that have oozed out on to its surface. Perhaps methanol is mixed in with it, since the water-methanol eutectic stays “liquid”, in a gelid way, down to very low temperatures. Thus the oozing, from wounds caused by volume cracking as water freezes in its once fluid mantle. Giant ice-moon scabs…

New Horizons headed for Far Horizons

The fastest launched probe ever, “New Horizons”, is on its way to Pluto and Charon, set to arrive 14 july 2015. Equipped with a powerful little telescope the probe will be doing useful observations for three months before the closest approach and considerable time afterwards. Then it will cruise on to encounter another TNO or two before it runs out of RCS reaction-mass. It won’t overtake our fastest near-Interstellar scout, “Voyager II”, which is over 111 AU away already, but it will travel on far beyond the Sun’s family.

Rivers of the Moon?

LCROSS crashed into the Moon and kicked up a watery plume…

The Moon is Wet!

Moon Crash Reveals Water
Significant Water found on the Moon

…there are hints from the plume’s spectral signature of other chemicals, probably comet like stuff like carbon dioxide, methanol, cyanide etc. We’ll just have to wait and see.

Now we know it’s there what can we do with it? The permanently shaded craters are a forbidding environment, with temperatures colder than Pluto’s 43 K, so they’ll be good practice for missions to the Outer Solar System. Mining such frozen masses will require some interesting technology – I’m hoping we’ll study such ice before we try to utilize it, since it’ll be a chronological record of water vapour on the Moon. Potentially. We don’t really know much about how it’s distributed yet. If it has been adsorbed into the regolith then there’ll be next to no trace of its history. If it has formed layered deposits then that’ll be a great boon for science and a good reason not to go crazy with the stuff.

Water discovery fuels hope to colonize moon

Launching from the Moon via using the indigenous water will probably mean most of the reaction mass – water – will return to the Moon as a temporary atmosphere that we now know will stick to the regolith until it’s probably returned to the ice-traps at the poles… if we don’t get in its way and dig up the poles too much. The frigid shadows of the Moon are, oddly enough, a resource that will serve us well if we respect it. That’s a lesson that Space makes easy for us to learn, because failure to do so is usually lethal.

A Secret Gospel?

Prof. James Tabor is a scholar whose work on Second Temple Judaism and early Christianity I have a lot of respect for. His teacher, in turn, was Morton Smith, who attracted a storm of controversy in his life because of his discovery of “Secret Mark”, quoted in a previously unknown letter by the early 3rd Century Church Father Clement of Alexandria. James Tabor discusses this episode in his mentor’s life here… Vindicating Morton Smith …which is worth a read. His blog post was sparked by a very even-handed treatment of the controversy in the latest Biblical Archeology Review (Nov/Dec 2009)… Secret Mark: An Amazing Discovery …and a previous Tabor Blog piece on the latest status of the debate over “Secret Mark”. The previous Tabor-blog piece references this
article by Anthony Grafton which discusses Gershon Scholem’s influence on Morton Smith and their correspondance which makes the ‘forgery’ case more unlikely for any fair-minded observer.

So what of the offending piece itself? The indispensable Early Christian Writings website discusses “Secret Mark” in detail and provides a translation of Clement’s putative letter in which the contentious text is quoted. In the end one either follows the data on trust or retreats into utter scepticism. There is no slam-dunk argument or clue in this case.

Other Links:
A short summary of arguments in favour of authenticity
Book blurb on “Secret Mark” …and a not so friendly review.
An interesting thesis… Identification of the Bethany Youth in the Secret Gospel of Mark with other Figures Found in Mark and John
…a surprising answer, but not a unique conclusion as to a certain mysterious disciple.

Stickier Cells for a Cambrian Explosion

Darwin’s Mystery was, amongst the many puzzles that great scientist tackled, was the perceived lack of fossils in rocks older than the Cambrian. Why were those earlier rocks bare of life? Did that indicate a vast span of missing time for life to evolve in? Since then we have found somewhat older animal life, but even those ancient forms seemingly appear abruptly and no ready answer has arisen as to why exactly. Two types of explanations have arisen – external and internal. Either the external conditions became “just right” for animals to arise/bloom or something internal in animals made them ready for an abrupt appearance. Several external factors have advocates – a spike in oxygen levels, a decline in certain sulfides (sulfates?), a sudden spate of erosion in the wake of the Cryogenian glaciations. And several internal explanations – new genetic regulatory networks, whole genome duplications, the rise of predators.

But none really address just how animals got together in the first place from single celled organisms and just why those single-celled precursors (of which there are several candidates) began sticking together. What if cells suddenly got stickier? This is what Fernàndez-Busquets, Körnig, Bucior, Burger, & Anselmetti have concluded from a microscopic examination of just how animal cells stick together….
Molecular Biology and Evolution 2009 26(11):2551-2561; doi:10.1093/molbev/msp170 …in an article entitled…

Self-recognition and Ca2+-dependent carbohydrate-carbohydrate cell adhesion provide clues to the Cambrian explosion.

…they argue that the rise in calcium levels in the oceans at the end of the PreCambrian allowed sponge cells to stick together easier thanks to self-recognition proteins in their cell walls.

A talk by Anselmetti…
PubMed Reference
NextBio reference
News Report from Everyday Science
University of Catalona report
ScienceDaily News piece

Perhaps the more interesting report is this blog post… StratigraphyNet post …which summarises the conclusions about the shift in Pre-Cambrian ocean chemistry providing an opportunity for organisms with pre-existing mutations to just stick together.

So an internal and external explanation in one. Question is: what does it tell us about the evolution of animal life on other planets? Does calcium chemistry matter there too? How many more molecular peculiarities are needed for complex life? How many are possible? Inevitable?

As always… need more data.

A Captured Moon?

Most workers in the cosmogony business take it for granted that the Moon formed from the remnants of an impact between the early Earth and a Mars-mass object, usually called ‘Theia’. But that’s not the only theory. Throughout the 1970s and 1980s, in parallel to the Big Impact research effort, Robert Malcuit of Denison University was working on a Capture theory for the Moon’s origins, in an effort to explain its curious refractory rocks and the odd pattern of maria on its nearside face.

Of course, in hindsight, one can see the Capture origin idea was eclipsed by the simulation successes that Big Impact theorists have had, and the fairly strong direct geochemical evidence for kinship between Earth and Moon rocks. However not everything is so easily explained by the Big Impact and it’s by no means a ‘proven’ theory of Moon origin, merely a very good one. Science advances by distinguishing betweening good competing theories via experimental tests. But what discriminates between possible events that occurred about 4 billion years ago?

More later.

Relevant links…

MSNBC: Controversial moon theory rewrites history

Robert Malcuit’s page at Denison U…

2007 GSA Meeting…

Science News report from 1987…

Denison U Magazine piece 2007…

Discovery Channel News 2009…

NASA ADS entry on ‘Robert Malcuit’…

ADDENDUM:
Abstracts from the GSA 2009 meeting…

A RETROGRADE PLANETOID CAPTURE MODEL FOR PLANET VENUS: IMPLICATIONS FOR THE VENUS OCEANS PROBLEM, AN ERA OF HABITABILITY FOR VENUS, AND A GLOBAL RESURFACING EVENT ABOUT 1.0-0.5 GA AGO

A PROGRADE PLANETOID CAPTURE EPISODE ABOUT 3.95 GA AGO: IS THIS MODEL COMPATIBLE WITH THE INFORMATION FROM HADEAN- AND ARCHEAN-AGE DETRITAL ZIRCON CRYSTALS?

To the Moon

Emily Lakdawalla’s Planetary Society blog reported on the long-awaited discovery of a Lunar cave ‘skylight’ thanks to high resolution imaging from Japan’s Kaguya orbiter… Lunar cave sky-light from Kaguya in the Marius Hills

…subterranean caverns are a near perfect site for a large, well-protected outpost on the Moon – stable thermal environment and radiation shielding are just two of its virtues. Of course this finding synergises well with the discovery that the Moon is wetter than expected from examination of “Apollo’s” samples…

Space Review: Water on the Moon …it seems the USSR’s Luna 24 drilled a 2 metre deep hole and found the regolith to be “wet” – containing water in the parts per thousand range rather than the average “Apollo” sample levels of parts per billion. Potentially there’s a lot of water in the regolith… a lot more than we first expected, at least.

Now we have a place to stay and something to drink when we get there just how do we get to the Moon in style? Ad Astra Rocket Company is developing the VASIMR high-power plasma thruster, as reported here…

VASIMR testing at 200 kW

here too…

from MoonToday…

New Scientist: To Mars in 39 Days via VASIMR

…the last headline being the least accurate. A 39-day trip to Mars requires a 200 MW power-source and a 600 ton space vehicle (476 tons propellant/tankage, 100 tons reactor/VASIMR, 24 tons payload), neither of which is forthcoming soon. But a flight to the Moon needs just 200 kilowatts of power – inflatable solar concentrators from L’Garde could do that for about 24 kg of mass. A Moon shuttle isn’t a huge challenge if we dare!

Life began in a flash…

Life began in a flash; Science takes four billion years to catch up: Scientific American Blog.

Making the chemical sub-components of RNA is tricky. So tricky that veteran Origins-of-Life researchers like the late Leslie Orgel despaired of cracking the puzzle. It’s a shame he didn’t see this particular leap forward.

A different unsuspected property of DNA has as yet unknown consequences…

Does DNA Have Telepathic Properties?-A Galaxy Insight.

The Daily Galaxy re-reports on the curious finding that DNA segments are attracted to segments like themselves.

Beyond the Desert Earth…

Long, long after Earth has dried up it may end up locked tidally into facing the Sun on one side and the Cosmic Heatsink on the other, forever. What would such an Earth be like?

Earth: 7.5 Billion AD

…a description of an end-state scenario described by Jeffrey Kargel in 2003 (“New Scientist” article… “Hell on Earth” ), best seen in this graphic…

(a larger version can be found here… graphic) Basically one side of the Earth is a magma ocean at 2500 K, while the other is covered in the deepest, coldest night at 33 K. In between is an annular ocean surprisingly of liquid water. An ocean between silicate rain and argon snow. What strange remains might be scavenged from the strata of the Earth that many aeons beyond our day? What would we leave behind?

“Noise”

Harry Stubbs aka ‘Hal Clement’ was the Grand Master of alien planet building with such classic creations as Mesklin, Dhrawn and Tenebra. His last creation, prior to his passing in 2003, was Kainui in his novel “Noise”, which I finished reading yesterday. Kainui, as the name implies, was settled by Polynesians and the protagonist is a Moari from Earth who has come to Kainui to study its languages and their evolution on a new planet. Hal Clement books are known for their memorable alien characters, but in “Noise” the planet itself is the alien encountered. Not in a “Solaris” sense of being a unitary alien mind, but because it is so alien an environment, one to which the Polynesian colonists have had to adapt to.

Kainui is the inhabited member of a binary planet, which in turn orbits a pair of M class stars. It masses just 0.44 Earths, but has a radius of 1.15 Earths, thus a surface gravity of just 0.33 gee. The density is just 0.29 of Earth’s because the planet is covered in 2900 kilometres of ocean, which is liquid for much of its depth, but supercritical near the magma of the core. As a result of such intimate contact with the core, the global ocean is in a continual state of violent agitation, a constantly lethal din of underwater shock-waves which can kill any unprotected human much as dynamite in a pond kills fish. Also the atmosphere is filled with electromagnetic noise from endless storms, lightning filling its clouds and waterspouts are a continual hazard. Fortunately the endless spray of ions means no lightning can reach the ground – any charge leaks away too quickly – but above about 100 metres lightning becomes a risk. The atmosphere is bereft of oxygen and there’s no land or native life – how do the colonists survive?

All cities are afloat and dependent on a nanotechnological pseudolife ecosystem for food, oxygen, freshwater and metals – the latter two related by metal ions being accumulated by the removal of salts from the seawater. Vast pseudolife “fish” harvest ions and water deeper down, closer to the core, then rise for solar energy accumulation and tapping of their produce by humans. Due to the lack of long-range communications the planet can only be navigated, not mapped, and so the “fish” float freely, their bounty claimable by any who encounter them. People set out for months, years at a time of sailing the open ocean in search of promising “fish” and profitable trading with other crews and cities, usually in a small crew of adult sailors and young apprentices hoping to earn their adulthood through meritable sailing skills.

All in all Hal Clement has created an alien yet believable world inhabited by ‘alien’ people who are still familiar enough to care about. Kainui, in light of the multitude of Super-Earths and Hot-Neptunes discovered since 2003, is representative of many planets beyond our Solar System – Clement’s tale seems uncannily prescient in that light.