Category: Carnival

Life On Titan!

Hints of life found on Saturn moon – space – 04 June 2010 – New Scientist.

CASSINI News Bite

Something is eating acetylene and hydrogen on Titan! Ok, so it might be chemistry, bare and unadorned by the complexity that is Life, but the two missing gases are exactly what would be used by an exotic metabolism suited to the -180 oC temperatures. We won’t know until we go!

But just how will we get there? A new paper by Ralph McNutt describing one possible architecture is discussed by Brian Wang at Next Big Future. A flaw in his analysis, aside from its conservatism, is the curious concern over mission criticality of a magnetic shield failure against cosmic rays. However the main drive – a high-powered VASIMR – and the main power – a low mass nuclear reactor (probably MHD) – both will require years-long, continuous performance from high-powered magnetic systems. Why aren’t their failure as likely or unlikely as a magnetic shield? Cryogenic propellant tanks will need to be protected against micrometeorites, presumably by low-mass Whipple shields, so why can’t a cryogenic magnetic field coil system?

I just don’t get the logic.

Prospects for Oxygen-Breathers in Europa

An MSNBC news-bite covering a recent study by Richard Greenberg, long time Europa researcher, which quantifies the delivery of oxygen, produced by photolysis of surfaces ices, to the ocean beneath. The ocean seems to be highly oxygenated and, Greenberg estimates, able to support a macro-fauna mass of 3 million tons.

Kind of old news since I’ve discussed it before, but new to MSNBC. The juxtaposition of that news-bite with the arXiv-org blog’s coverage of this paper: A natural mechanism for l-homochiralization of prebiotic aminoacids …which explicates an elegant solution to the homochirality of biomolecules via convection around a deep-sea vent. Yes, as simple as that. Apparently amino acid crystals, alanine for example, form slightly larger crystals in one mirror-form than the other. That disparity is enough for one chirality to accumulate in excess, then gradually convert the other form into its own chiral state. Easy.

And Europa’s chief heat-source? Deep-sea vents, or the equivalent thereof.

Beyond “Icarus”


Where we’re at and where we’re going. Alpha Centauri, resolved into A & B, as seen by “Cassini” from orbit around Saturn.

After we send the probes, like “Icarus”, the next step is going ourselves to live in those new planetary systems we’ve explored remotely. To get there IMO we’ll need to go en masse in one of these…

Rick Sternbach worked with Robert Enzmann on the Enzmann starship design and it’s quite an impressive concept – you’ll see different iterations here from time to time. Basically use the fuel & its tank for forward shielding and make it really, really huge. We’re looking at 12 million tons of deuterium propellant in one of those spherical ‘slush’ tanks. With a mass-ratio of ~20-150 the delta-vee is ~3-5 times the exhaust velocity, which itself can push ~0.06c or more.

Of course some kind of materials break-through might change the basic concept. We’ve looked at Ultra-Dense Deuterium (UDD) here before – ‘collapsed’ deuterium that’s 1 million times denser than its ice-phase. The huge Enzmann main-tank could shrink 100-fold in all dimensions and hold the same amount of deuterium in that state – if it remained stable in bulk. The collapse of deuterium also releases potential energy and might explain “cold fusion”, with some fusions occurring because of the extreme density to produce the observed radiation from “cold fusion” reactions.

But with UDD we could do really “wild” things with the propellant and even the basic fusion rocket concept. Imagine a massively ‘cellular’ rocket, which throws off (or consumes) tanks and engines as its mass-ratio declines. Robert Goddard used such a design for his 1920 Moon rocket concept that attracted so much ‘negative’ publicity. With such mass-ratios could push 1000-10,000 or so. That’s 7-10 times the exhaust velocity for the delta-vee – heading towards 0.6c delta-vee.

One of my areas of “Icarus” research will be investigating the potential for braking a fusion vehicle without using propellant via a ‘magneto-plasma sail’ or a ‘magnetic sail’. If such were proven workable, then our extreme mass-ratio rocket could cruise between the stars at 0.5-0.6c – pretty damn good performance for a mere fusion rocket. The more I learn about the difficulties of high-energy propulsion, the more such speeds seem fantastic – in both senses of the word. Yet difficult goals drive novel thinking – or should.

Summer on Triton – Ballooning Season

ScienceShot: Summer on Triton – ScienceNOW.

Triton’s troposphere is a COLD mix of nitrogen and methane, currently at a pressure of roughly 40-65 microbars (4-6.5 Pa @ 38 K, near surface.) Interestingly JP Aerospace claims an ultra-high altitude airship can get to ~200 kilo-feet. At that height the pressure is a mere 17.76 Pa and the temperature is 242.7 K (computed via the International Standard Atmosphere Calculator.) Think about it. Density varies inversely with temperature, so a gas at 38 K is 6.5 times denser than it is at 242 K – thus that 6.5 Pa @ 38 K is the equivalent of 42 Pa at 242 K. The air on Triton is denser than the air JP Aerospace thinks they can fly an airship in.

RTGs are the main-way Deep Space probes are powered and warmed. Electricity is only generated at a pitiful efficiency of ~5% or so, the rest radiated as heat – perfect to form a hot-air balloon in an atmosphere like that of Triton. Works even better on Titan and forms the basis of a current mission proposal – but I think what’s good for Titan is better for Triton. Lower gravity, colder atmosphere and Triton is as geologically weird and diverse as Titan. Perfect!

You’re Mostly Energy

Mass of the Common Quark Finally Nailed Down – ScienceNOW.

Matter is made up of mostly protons and neutrons – as important as electrons are, they’re only a tiny fraction of the mass of most elements. Oxygen-16, for example, has just 8 electrons, massing just 4.88 MeV, but has 8 protons and 8 neutrons that mass almost 15,000 MeV collectively. Since the 1960s protons & neutrons have been theorised to be made of trios of quarks engaged in a complex dance of exchange gluons & virtual-pair quarks, boiling around in a complex manner. Why so? Because the ‘colour force’ that binds quarks together gets stronger the further apart individual quarks are dragged from each other. This increasing strength pulls new quark/anti-quark pairs out of the vacuum and so the constituent ‘valence’ quarks are never alone.

Now some theorists have managed to compute, the hard way, just how much the valence quarks inside protons & neutrons actually mass. The answer is in this quote from Adrian Cho’s report for Science Magazine…

Now, Davies and colleagues have essentially turned the process around and used lattice QCD to calculate the up-quark and down-quark masses. The individual quark masses usually serve as inputs that get tuned to the appropriate values during the calculation of the hadron’s properties. It might seem like physicists could simply write down those values and call the problem solved, but it gets tricky. The exact values of the quark masses depend on mathematical methods used in the simulation. Moreover, each quark mass comes out with a sizable uncertainty. Davies and colleagues found a way to get around such problems, however. Instead of trying to calculate the mass of each type of quark independently, they calculated ratios of those masses.

Specifically, they calculated the ratio of the charm-quark mass to the strange-quark mass. They combined this with calculations from another group of the ratios of strange-quark mass to up-quark mass and to the down-quark mass. Those ratios come out with much smaller uncertainties, explains G. Peter Lepage, a team member from Cornell University. And they can be combined with an already-known value of the charm-quark mass—which is easier to determine because it’s about 500 times bigger—to finally nail down the masses of the lightest quarks, as the researchers report this week in Physical Review Letters. The team finds that an up quark weighs 2.01 +/- 0.14 megaelectron-volts, whereas a down quark weighs 4.79 +/- 0.16 MeV. That’s 0.214% and 0.510% of the mass of the proton, respectively.

So the up quark is roughly 4 electron masses (0.511 MeV) and the down is roughly 10. Which means most of your mass is tied up as “binding energy” or “kinetic energy” from the vigorous motions of quarks inside the protons/neutrons of the atomic nucleii of the elements of your body. Protons are ‘uud’ (two ‘ups’ and a ‘down’) and neutrons are ‘udd’. That means, roughly speaking, the quarks are zipping around inside those nucleii at roughly ~ 0.99994 c and experiencing a time-dilation factor of ~90. Which poses the question, in my mind, of just how warped reality really is… 😉

Dark Matter puzzle?

Astronomers Find Black Holes Do Not Absorb Dark Matter

The media produced breathless copy like the above, which comes from one of the more considered and sensible space science news-sites, Universe Today. The ‘headline’ was inspired by this paper…

An upper limit to the central density of dark matter haloes from consistency with the presence of massive central black holes

…which does seriously challenge the naive model of dark matter in its “plain Dark Matter” form – i.e. responds to gravity and only interacts with other Dark Matter via annihilation reactions. But what if Dark Matter is more complicated? Some theories argue for other Dark Matter forces that it alone feels. If Dark Matter is “Shadow Matter”, which has a full suite of Standard Model forces, but in mirror reflection to Normal Matter, then Dark Matter is subject to “dark light”, its own kind of electromagnetic forces. Remember all varieties of proposed Dark Matter feel gravity and a central galactic black-hole is going to be a black hole in either the Normal Matter or Shadow Matter ‘universes’. But there’s more Shadow Matter than Normal Matter and, due to differences in Big Bang Nucleosynthesis, the ratio of hydrogen’ to helium’ is lower than the Normal Matter H/He ratio. The Shadow Universe began old, with a higher metallicity driven opacity in its star-forming gases. That means in the Shadow Universe the Galaxies never condensed into flat disks because supernova blew them into huge hot bubbles, surrounding Normal Matter galaxies as the observed Dark Matter haloes to the present day. Thus Shadow Quasars, and their black hole engines, blew away any excess central density in the Shadow galaxies and the central black holes were starved of Dark Matter, as the new study observes.

Thus the new study isn’t telling us that Dark Matter is somehow immune to Black Holes, which is utterly contrary to the gravitational justification for Dark Matter in the first place. Instead Dark Matter is more complex than the simple variety invoked as the minimal working hypothesis. There’s much more to learn about the Shadow Universe than we first thought – surely that’s got to be a good thing?

Carnival of Space #145

Roll up! Roll up! The 145th Carnival of Space is Here!

In no particular order the Shows on offer…

Steve’s Astro Corner this week memorialises the life of a telescope mirror grinding Maestro… Dick Wessling: A Tribute to Gifted Hands

Astroswanny (at AART Scope Blog) rallied to the call of the AAVSO to keep a close eye on GW Lib – else it might spoil the work of the HST – and pulls off a challenging observation.

Mike Simonsen, at Simostronomy, gives us another view of the GW Lib campaign: Okay Hubble, You’re Safe To Go… The AAVSO has your back.

Louise Riofrio, A Babe in the Universe, handles through positive pressure gloves a real piece of the Moon.

…the road to endeavour… follows the “Opportunity” MER (‘Oppy’ to her friends) as she braves the harsh Martian conditions and farewells Concepcion.

Weird Warp tells us How Impact Craters Are Formed.

Dr. Schenk’s 3D House of Satellites gives us the Mimas Rejoinder: Those Pesky Icy Satellites Between the Rings and Titan, reminding us of the gyre of Icy Moons that circulate around Saturn too.

At Chandra blog, Chandra the X-ray telescope, muses on The Poetry of Discovery, particularly a poem by Jonathan Taylor about the tune of a Super-Massive Black-Hole. And I thought that was already a “Muse” song.

Amanda Bauer aka Astropixie gives us a penetrating view of Dirty Space News…

A 150 Kiloton warhead up too close for comfort

Brian Wang, at Next Big Future, gives us the Biggest Circus Cannon Act ever! The 150 Kiloton Nuclear Verne Gun in fact. Plus thoughts from Burt Rutan on the *cheapest* tickets to space you’ll ever see! Not on the Verne Gun I hope!

CollectSPACE reports on the Hubble-in-3D Premiere. With real live astronauts!

Alan Boyle, at Cosmic Log, tells us how PLuto has found its place… it’s a little planet with a lot of friends.

The Shuttle Era tells us Bob Parkinson’s 1981 Plan: Mars in 1995! David Hardy kindly gave permission to David Portree to use some high quality images from artwork he did for the plan, so I won’t use the images here because I haven’t asked. Worth seeing!

Cheap Astronomy podcasts a short Stay-At-Home’s Guide to the Galaxy, probably more useful than “The Hitchhiker’s Guide”.

The Gish Bar Times tells the Tale of Gish Bar Patera, a very active piece of volcanic Real Estate on Io, but not active all the time.

Centauri Dreams works the Numbers of Habitable planets in our Galaxy & Beyond. Just how many though? How about 45.5 billion in the Milky Way alone!

One Astronomer’s Noise brightens our minds with AstroJargon of the Week – AGN.

The Bad Astronomer colours the Stars this week with a Hex on Star Colors. Did you know the Sun is #FFF5F2?

Colony Worlds gives us a not-so-crappy way of preparing Martian dust to make it real plant-friendly soil… Could ‘PeePoo’ bags help fertilize Martian soil? In space nothing is waste…

Finally, Crowlspace discusses Buzz Aldrin’s alternative plan for NASA’s new direction away from the Moon. Plus my latest essay at “Project Icarus” just went online… What Else is ‘Daedalus’ Good For?

Lunar Ice, Aldrin’s Mars & Further Options

Two new interesting news items, both discovered via Synthetic Aperture Radar (SAR) scanning by orbital space-vehicles. First target is the Moon… Water Ice Found on Moon’s North Pole …some 600 million tons of the stuff, found as ice a couple of metres thick lining the floors of 40 or so small craters around the Moon’s North Pole. The India moon-probe Chandrayaan-1 carried an American SAR instrument into Lunar orbit and successfully scanned the Moon before the probe packed it in. Now data analysis is producing these sort of reports, more which will appear thanks to the 41st Lunar & Planetary Sciences conference that is currently happening in the USA.

The next target is Mars… JPL News Buried Martian Ice …which has even more ice present than first imagined, buried under regolith so it doesn’t evaporate away to the Poles. Very handy for future colonists. Discovered via a Shallow Radar system on the Mars Reconnaisance Orbiter mission. A lot of it is very clearly associated with erosional basins, thus some kind of water/ice based weathering created the features and eventually trapped the ice there.

Buzz Aldrin has recently come down on the side of the Obama administration’s axing of the “Return to the Moon” program GWB began in the wake of “Columbia” burning-up in 2003. For a Moon-Walker that might seem a strange position to take, but Buzz’s position is more ambitious than the apparently “purposeless” (i.e. non-vote related) program of NASA. He wants commercial space-vehicles servicing the ISS while NASA builds a real space-ship, the XM, a space-ship ultimately bound for Mars. And he thinks we should use all the remaining bits of Shuttle etc. to do it.

I agree with the spirit of his plan, but I have one reservation. The Moon has a long-term resource that Mars doesn’t seem to have. Mars is the destination for colonization and ultimate transformation, sure, but the Moon has about ~2.5 million tons of 3He in its regolith, and I believe that will be vital to building high-speed fusion propelled space-ships. But we need to “ground truth” those proposed solar-wind deposited resources of the Moon. And there will be more than just 3He, which is very rare. All that lunar hydrogen, bound up as water-ice, will contain deuterium, another fusion fuel and vital for CANDU natural uranium reactors.

But here’s where Mars has an advantage – deuterium. Mars is enriched in the stuff, at least the water we can see is. Ideally we need both worlds, something only serious propulsion systems, like fusion, can give us.

Everything Old… a corrective

Hi All

My first reaction to the “New Scientist” reporting the conclusions of William & Arthur Edelstein was to write an angry blog-post, but then I realised that such gamma-factors (~5,000) run up against the thermal glow of the galaxy and the CMB red-shifted into a white-hot blaze. It’s not just the proton radiation we have to worry about too. Dust, cosmic-rays and so on, all get focussed & intensified by relativistic aberration as well as the blue-shift. Essentially a “hard wall of light” forms, making such extreme speeds unhealthy. So I’m inclined to agree with the Edelsteins, though James Essig’s suggestion of ultra-dense matter shielding may well be the ‘unobtainium’ miracle needed to ultimately achieve such. However since the intensity falls off rapidly at lower gamma factors, this really isn’t an impediment to more modest ranges – a gamma-factor of ~50 would experience a much more benign radiation field.

Interestingly Alastair Reynold’s fictional “House of Suns” deep future view has maximum speeds of a mere 0.9999 c, even though they’re protected via some kind of space-time ‘interdict’ shield – though it’s hard to imagine what could power million ton starships doing 1200 gees at 0.999c…

Warming White Dwarfs with Dark Matter

Two recent arXiv preprints discuss capture of Dark Matter and limits on its self-annihilation inside white dwarfs…

Capture of Inelastic Dark Matter in White Dwarves

Inelastic Dark Matter As An Efficient Fuel For Compact Stars

…the first discusses limits for inelastic Dark Matter capture inside the white dwarfs of globular cluster M4, while the second discusses capture in general. PhysicsWorld.com has a commentary news-piece on the limits and the putative inelastic DM signal from the DAMA/LIBRA experiment… Warm white dwarfs could reveal ‘inelastic’ dark matter …and mentions white dwarfs maintaining an even 7000 K temperature, rather than cooling towards ~3000 K (what the coolest WDs radiate at.)

What does that mean, in the long term, I wondered? Consider the average white dwarf, which is about 0.7 solar masses and about 0.0093 solar radii. Call it 0.01 size of the Sun. At 7000 K each square metre is radiating x2.15 times the Sun’s 5780 K, thus the white dwarf is putting out about 0.0002 Solar luminosities – i.e. about 5000 white dwarfs would equal the Sun. Since the galaxy is expected to evolve to a state of being either white dwarfs or brown, then there will be about ~20 million solar luminosities worth of Dark Matter annihilation energy radiating from them until the Dark Matter runs out some time between 1019 – 1020 years from now.

The SETI implications are interesting – does it imply that civilizations with an extremely long-view will ultimately move into residence around white dwarfs? Such would live ~1-10 million times longer than red-dwarf based societies, which is quite impressive. Of course a mere 1020 years is nothing compared to eternity…