Wednesday, December 30, 2015

Dark matter anomalies, galaxies, moons and more!

Perfect fare to start off the New Year and give you that desperately needed jolt of optimistic determination -- every few years this epic-good short film - Wanderers -- gets rediscovered by the Web and re-viraled. As it should, be, yet again. It is that good. That beautiful and inspiring.

== Dark Matter anomalies ==

Let's dig in for one of our periodic space and science compilations, as a way of celebrating what has to have been by-far humanity's best year in exploration of the cosmos. A truly spectacular year... almost as amazing as the fact that almost none of our fellow citizens even remotely realize it.

And so...

Streams of dark matter particles may interact with our planet’s gravitational field. Non-baryonic mass seems to not engage our kind (baryonic) via electromagnetism or interacting with light. But we know it is out there, from the orbital speeds of stars around galactic centers… and from cases of gravitational lensing.  Now this “stream” concept intrigues: “A (dark matter) stream can be much larger than the solar system… perhaps many streams crisscross our galactic neighborhood… When gravity interacts with the cold dark matter gas during galaxy formation, all particles within a stream continue traveling at the same velocity.”

Further: “As these streams begin to interact with a planet, according to results from his computer simulation, the streams pass straight through, focusing as an “ultra-dense filament,” producing many dark matter “hairs” that seem to sprout well above Earth’s surface. This stream will not interact with our planet’s normal matter, it will pass through as if nothing were there, but channeled by the intensity of Earth’s gravity.

And: “For Earth, the dark matter streams will emerge from the planet, concentrating as “roots” of the dark matter hairs around 600,000 miles above the surface (about twice the Earth-moon distance)… “tips” of the hairs should be located over twice as far away from the planet’s surface….”

What’s cool is that this hypothesis should be testable with sensitive gravimetric satellite probes. Already some discrepancies seem to point to dark matter anomalies… though not yet “hairs.” 

== Moons, asteroids and more ==

Go to Phobos before landing on Mars itself?  I have pushed this idea for twenty years and now some at NASA agree.  Not only is the larger moon far easier to reach and might serve as an ideal research platform, it also has two advantages never mentioned in this article.  It can serve as a logistics hub where supplies might be pre-positioned and tended without complex orbital management.  It also might (some figure) be carbonaceous chondritic material, containing volatiles like water.  If these could be mined and stored and prepared, subsequent Mars landing missions would find all the water and rocket fuel they need, lowering both cost and risk by an order of magnitude.  

I’ve long held that Phobos, the larger moon of Mars, is one of the most valuable pieces of real estate in the solar system.  Certainly the Russians seem to think so, though none of their efforts have delivered a lander, yet.  (Note, Phobos has far less of a gravitational well to deal with than out vastly larger Moon, which renders the latter almost useless as a staging area or logistics hub.)

Now there are indications we had better hurry!  There may be only a little time left to exploit this resource! Phobos is being slowly torn apart by gravity as it approaches the Red Planet at a rate of 2 meters every century, a rate that will cause it to break apart completely within the next 50 million years. Mars may lose a moon, but gain a ring, so hurry up!

Speaking of fascinating moons… “At half the diameter of Pluto, Charon is the largest satellite relative to its planet in the solar system. Many New Horizons scientists expected Charon to be a monotonous, crater-battered world; instead, they're finding a landscape covered with mountains, canyons, landslides, surface-color variations and more.” Signs of a possible once-molten interior point to very active early days in the solar system.  And the features on one side of Charon are named after… science fiction characters!  The other side, never seen clearly by New Horizons, will get names only after some future mission… so make my characters famous and beloved enough to get places of their own!  

== More excitement... for those capable of looking up ==

Oh, what a wonderful year it's been, in humanity's advancement through space and the cosmos!  Possibly the best year ever, and I include the 1960s.  And now -- the Cassini probe just completed a dive to within 50 kilometers of Enceledus, Saturn's little moon whose under-ice ocean is spewing plumes of water into space.  Cassini’s passage through those plumes will reveal much about ice-roofed ocean moons and the possibility they may be abodes of life. 

A new study, published in Science, suggests that the asteroid or comet that impacted the Earth 66 million years ago rocked the planet severely enough to set off massive volcanic eruptions in India, spreading lava across the Deccan Traps. Together, the impact and volcanism finished off the dinosaurs and 70 percent of the Earth's species.

By now you’ve all seen the news (dismissed as a hoax by Rush Limbaugh) that there is (briny) liquid water occasionally flowing on a current-day Mars.  Suggesting that the precious material is both more common and accessible than expected. Not everyone greets the news with enthusiasm, though: “…but the very fact that it’s in a liquid state is troubling. In fact, it could be deadly.”  Because highly caustic perchlorates are known to be common on Mars and these may be among the salty substances in the brine-stew. And perchlorates destroy organic compounds. (They are also components of solid rocket fuel.) Though there are also a few earthly organisms that find them yummy.  And who can fault a liquid that's... brin-y?

Once a week a thousand ton asteroid passes between the Earth and Moon.  Thousands of small ones are easier to reach energetically than the surface of the moon, and laced with vastly more useful minerals. This spooky “skull-shaped” asteroid passed near us on Halloween!

Three times as far away as Pluto, V774104 is officially the most distant object yet in our solar system.

== Galaxies and black holes ==

Most galaxies appear to have a supermassive black hole at the center. About one percent are “active galaxies” where this central black hole is sucking in matter fast enough to create fierce jets, spewing from the north and south poles. A ‘blazar’ happens when one of these jets happens to be aimed our way.  In one case, the Fermi orbiting gamma ray observatory has seven years’ data suggesting a two year periodicity with real implications.  Stay tuned. 

Have we found evidence of another universe bumping into ours? Some anomalies in the Cosmic Microwave Background (CMB) might — (not the top probability, but not excluded) be caused by contact with another “bang” cosmos next to ours.    

An aged mini-galaxy, near the Milky Way, has just 1000 or so stars and is making no new ones… yet its dark matter component may be huge. A number of dwarf galaxies - just discovered - are changing our perceptions.

A lovely article on the newly augmented LIGO gravitational wave detector system that recently came online and that may finally give us a whole new window onto the cosmos.

== Space Technologies == 

The idea of Space Solar Power Satellites is making some headway. A proposal titled "Carbon-Free Energy for Global Resilience and International Goodwill" has been selected for semi-finals in the Secretary of Defense's innovation challenge.  Led by Lt Col. Pete Garretson, the group seeks to "empower global prosperity and security: through a three step program leading to an ambitious international on-orbit demo of an orbital power station within 10 years."

Cool… literally!   3-D Printed Igloo Wins Mars Habitat Contest.  If astronauts land in a place where water is abundant, this could be the ideal building material.  

Did I invent the concept of the “refrigerator laser?”  Someone find a mention before my 1980 novel Sundiver!  Now scientists claim to have brought a version into the real world, using an infrared laser to excite electrons in a single microscopic crystal suspended in water. That produced emissions that transmitted-away slightly more energy than the amount of light absorbed, and the surrounding water cooled.

Super Strypi is a system to launch a rocket along a 45 degree slanted rail in order to give it rapid turnaround and self-correcting spin, in order to access Low Earth Orbit with small payloads with minimized cost and time.  

Let me conclude this amalgam by thanking Elon and the SpaceX team for the finest Solstice present  - capping our best yet year in space.  Now every other rocket company will have to innovate and re-land their boosters too.  Just like Tesla forced them to admit it's time for electric cars.  Even if he winds up in the poor house, he will have changed the world. Forever.



Jumper said...

I mis-read the Super Strypi article on first pass. 41 meter rail; I read as 41 km. The carriage for a trans-sonic rail-driven launch would be hairy. Maybe most of the problem, in fact. But intriguingly solvable, I think.
Of course I want the rocket to ignite only at the end, after the rail driver already has it at 3-5 km/sec. What's the g for hitting 3 km/sec over 41 km?

Alfred Differ said...

Looks like about 27 seconds at a steady 11.2 g's to get to 3 km/s.

Not sure many of us could survive that. 8)

Alfred Differ said...

It was the refrigerator laser that captured me with Sundiver and brought me back to read your next book. I was working my physics degree at the time, so this motivated me to go learn more about lasers. Fun stuff.

Jumper said...

That's for cargo.

Ronald Pottol said...

Fighter pilots routinely hit 9g in an only semi reclined (27 degree seat back) position, and you don't need to breathe for 27 seconds, so on your back, it seems reasonable.

Ronald Pottol said...

Fighter pilots routinely hit 9g in an only semi reclined (27 degree seat back) position, and you don't need to breathe for 27 seconds, so on your back, it seems reasonable.

Jumper said...

One problem is that there are no 30km high mountains on this planet. I expect a fine rail launcher could be situated on Olympus Mons, and make returning people home a lot cheaper.

Paul SB said...

I looked over the article on a satellite-based solar power system, and wished the article was longer and gave more details. It sounds like an ambitious project, and one that would keep the engineers busy for a long time perfecting the technology. It's stated goals are:

The team is proposing the idea of Space Solar Power Satellites ... as a whole-of-nation way the US can re-assert US leadership in space, energy and other technologies, amplify the US leadership in the fight against climate change, create a huge number of US jobs and position the US as clean energy exporter, and rekindle America's spirit to do great things.

I like the sound of this, especially that last bit, but I would like to hear more about how such a project would impact the economy over a period of a few decades. Remember that paper on the shrinking middle class? I know correlation does not equal causation, but the shrinkage did begin around the time the space program began to shrink, along with other big government stimulated projects. Would this project spin off more high-paying and long-term private sector jobs? And would that spur more young Americans to get off their butts, get a good education and get good jobs, or would we just continue to hire India's and China's best and brightest?

Anonymous said...

It's time for electric cars... wait, what, again? They failed in the marketplace some 100 years ago, so this would be a second attempt. And to my fellow citizens who walk everywhere they need to go: may fewer car sitters make attempts on your life this coming year.

locumranch said...

It is 'hairy' threads like this one, so rich in non-literal metaphor & pompous analogy, which reveals the (superstitious; romantic) god delusion upon which modern theoretical physics is built, namely that 'dark matter' must possess magical 'non-baryonic' properties that allow it to be 'everywhere and nowhere', 'omnipresent yet undetectable', 'affecting of all things material yet unaffected by all things material', immortal, immutable and unchanging.

Why can't 'dark matter' be just that?

Matter, like ordinary matter everywhere, rendered largely undetectable either by current technical modalities, material diffusion (dilution) over parsecs or a 'lack of illumination' (otherwise know as 'darkness'). At least to the 'unenlightened', everywhere.

"Whereof one cannot speak, thereof one must be silent".


Charlie Hohn said...

The marketplace was pretty heavily manipulated then as it is now, hardly a free market. Also batteries were way worse then. But if we truly got very cheap energy I'd be more intrigued by the idea of splitting water and using hydrogen for fuel. I'm admittedly not that informed in how that is implemented but it seems wonderful... Less toxic than batteries and we could potentially export the fuel if we had a surplus.

LarryHart said...

Alfred Differ:

It was the refrigerator laser that captured me with Sundiver and brought me back to read your next book.

If you read the next five books, you saw that piece of human technology play an interesting part much later if the idea had been planned all along.

TheMadLibrarian said...

Hydrogen fuel cells have been around for decades. I've been waiting for the technology to progress to the point where they are viable for private homeowners and drivers to use for power production. Every so often one of the car manufacturers says that they are designing cars with hydrogen fuel cells, but I have yet to see any of them get out of testing, let alone near the market.

duncan cairncross said...

To the Librarian and Charlie
Hydrogen for cars is a scam
It is simply an attempt to keep motorists tied to "Gas Stations"

The big basic problem is that it takes a lot of energy to compress the hydrogen to a usable density
This gives a 20% hit on the energy in energy out balance - and that is before you start thinking about the inefficiencies and short life of fuel cells

Batteries are the way to go for 95% of applications - if a greater energy density is required then some form of "designer" liquid fuel would be the answer

Charlie - why do you think that batteries are more toxic than fuel cells??

Alfred Differ said...

@LarryHart: Yah. My reaction to Sundiver was "Oh. That's what science fiction can look like when written by someone who knows their science beyond the level of a popularizer." I've enjoyed David's books since then for both the narratives and technical details. Fantasy stuff is fun too, but only for when I'm in that mood. 8)

When it comes to ordering tech advances in terms of usefulness, I'm always inclined to put lasers right near the top. Not only do they demonstrate the quantum nature of reality, they do the rarest of jobs of delivering a coordinated output from an uncoordinated heat input. The second law of thermodynamics is a hairy beast all engineers face, but lasers seem to me to be an almost magical finding. Mother Nature makes life difficult and then hands us a magic wand. (Neat stuff)^2.

David Brin said...

Charlie, Duncan & ML. Hydrogen power may have a place in some future. But just making the infrastructure of delivery and storage of hydrogen leak-proof is far beyond any notion of cost-effectiveness. Hydrogen leaks! Like crazy.

Hydrogen w as a way for the Bush family to divert DOE funds away from research that might have actually helped the nation and consumers, into a boondoggle where the money mostly went to classic fossil companies for a system that - even if it eventually worked - would benefit the old fuel companies. One more case of flat-out bushite evil treason.

Alfred Differ said...

@locumranch: Thou art confused. Dark Matter is just the term coined to represent ‘stuff’ that doesn’t interact via electromagnetism (E&M). We know ‘stuff’ is out there AND that we can’t see it, therefore, it doesn’t interact much via E&M OR there isn’t enough to notice. We can calculate how much mass has to be present, though, and that measure conflicts with us not being able to notice the ‘stuff’, therefore, it doesn’t interact much via E&M.

In physics terms, this ‘stuff’ doesn’t scatter photons. No collisions OR collisions so rare we haven’t noticed. It has to be there, though, because it DOES interact via gravitation. Anything with a 4-momentum will do that. No magic needed here. Deduction is enough. Thus, silence is inappropriate.

(Neutrinos were discovered in a similar way. They DO interact via E&M, but not easily. This is a well-practiced arena.)

Alfred Differ said...

11 g's can be pretty hard on cargo too. For shipping sand, water, or something like that it wouldn't matter, but be careful with manufactured products. Since the primary stuff a non-terrestrial civilization isn't going to be self-sufficient in during the early years is refined goods, I'm skeptical of high gee cargo flights as a business model. It will work until the folks up there refine their own bulk resources and then you are stuck with a bunch of sunk capital on Earth.

ISRU is the only sane way to expand our civilization out there.

Paul451 said...

"Why can't 'dark matter' be just that?
Matter, like ordinary matter everywhere, rendered largely undetectable either by current technical modalities, material diffusion (dilution) over parsecs or a 'lack of illumination' (otherwise know as 'darkness'). At least to the 'unenlightened', everywhere."

Because it turns out that physicists actually aren't stupid, and have ruled out other forms of baryonic matter, including diluted gas or even subatomic particles, black holes (mini or giant), galactic halo clouds, etc etc. For it to be present in the quantities required for the observed gravitational effects, it would be observable in other ways. It would, for example, occlude observations through it, as dust and gas actually does. It would emit heat, as dust and gas actually does. It would interact with other matter (stars, etc) in observable ways.

Physicists have spent decades ruling out other candidates for the gravitational effects. Up to and included changes to gravity itself.

Through observations of the motions of stars in other galaxies, the motion of galaxies around each other, to the power of gravitational lensing of light from background galaxies, they can now map the extent and even shape of dark matter clouds in neighbouring galaxies independently of the baryonic matter. Hence they can spot galaxies (or clusters) with unusual excess of dark matter and a scarcity of baryonic matter (as in the article David linked to) or the opposite, find galaxies unusually stripped of dark matter (eg, NGC 4736).

"immortal, immutable and unchanging."

I've never heard any physicist say that, and it is certainly not amongst any of the current leading theories. The AMS observatory aboard the International Space Station was designed specifically to map the decay particles from the annihilation of dark matter.

" "Whereof one cannot speak, thereof one must be silent". "

And yet you continue to prattle about which you know nothing.

Paul451 said...

Re: Phobos as supply base.

The L1 point for Phobos is about 3km above the surface (shorter than the diameter of Phobos itself). Therefore a 6-10km Hoytether ribbon, made from Dyneema or Zylon fibre (think "Space Kevlar") coated with a metal conductor, would allow you to build a space elevator to lower/raise payloads to/from the surface of Phobos.

So instead of a tricky rocket landing at minuscule gravity on a loosely consolidated dusty surface, you just dock with the L1-hub of the ribbon (same as docking with ISS), xfer the payload to the elevator car and gently lower it to the surface. Reverse trip to bring fuel from Phobos to your ship. (Assuming ISRU fuel is available on Phobos.)

(Otoh, "Climb" the elevator and release from the very tip and you lower your orbit towards Mars with no propellant required. (Phobos gains a twitch of momentum.))

We've already deployed tethers up to 30km in space (Dyneema cable on ESA's YES2). This is well within our current technology. The hard part is anchoring it to Phobos. You can just "hover" the base over the surface, but elevators are more useful when anchored and under tension. (However, as a demonstrator, it would make a nice sample return mission.)

Re: Hairy dark matter streams

I wonder if the same (or even greater) focusing effect happens when they pass through the sun? If it's greater (more particles and especially denser streams), then there might be an optimum spot to throw an AMS-like detector satellite.

Re: Rail launcher.

Forget mountains. Use advanced (existing) construction materials to build a series of 30-50km heigh truss-towers running 200km long. Track runs across the top (or just below the top, like a suspension bridge). Either electric/magnetic or just old fashioned solid-rocket sled carries the upper-stage rocket to 4km/s at 4g. The (empty) sled can brake at a 100g's or so over the last 8-10km and be reused. Upper-stage carries the payload to orbit.

Gradually extend the line of 50-80km high towers (and hence the track) to 1000km, at which point you can reach orbital velocity at just 3g's without a rocket stage. (Although you will want to raise your perigee when you reach apogee.)

You can even return from orbit the same way. Although that manoeuvre will be... exacting.

Paul451 said...

Minor pedantry, from the last post:

Tony Fisk:
"My guess is Larry was thinking 'corporals'."

"notwithstanding specifically called out exceptions Napoleon and Hitler, one does not go directly from "Radar O'Reilly" to dictator in one shot."

Napoleon went through a normal (if amazingly fast-tracked) promotions path. He started as a 2nd Lieutenant (at 16!) and reached Brig. General (at 24!) before becoming the General in Chief of the Army. He was called "The Little Corporal" (le petit caporal) by his men as a term of affection (he tended to get down in the trenches with them, manually sighting artillery, reportedly even loading cannon himself in the middle of battle), but it was never a rank he held, and he certainly didn't go from Corporal to Dictator. The nickname was repeated by English royalists, thinking it an insult. But to his men it was meant to emphasise his egalite props.


Happy Arbitrary Point In Earth's Orbit to all.

Paul451 said...

(Or at least when the planet finally rotates your particular bit of continental plate to and beyond the point of local solar nadir.)

duncan cairncross said...

Hi Alfred
"11 g's can be pretty hard on cargo"

There is not much that can't take that if properly packed - complete assemblies would need some attention at the design stage but smaller sub assemblies should be no problem as they are.

Most smaller pieces end up massively stronger than they need to be to resist high g forces, the old cube square relationship

duncan cairncross said...

Off topic but I have just heard a comment that the extreme and continuing poverty of the old confederate states is due to extreme inequality

"Demonstrating once again that having 1% of the people hoarding all the money ( and property) does not result in a healthy economy"

David Brin said...

Paul451, do you have a link for that L1-point of phobos concept?

There are times when it's just best to let locum prattle. I am gradually coming around to the notion that he is congenitally incapable of awareness of how his remarks seem to others who have facts and educations and skills. I am increasingly doubtful that we accomplish anything by shaming or rubbing his nose in his deficiencies.

Paul SB said...


"Demonstrating once again that having 1% of the people hoarding all the money ( and property) does not result in a healthy economy"

From whence comes this?

Paul SB said...

Paul 451,

"And yet you continue to prattle about which you know nothing."

You can lead a person to knowledge, but you can't make him think. The willfully ignorant are immune to education.

duncan cairncross said...

Hi Paul

On the GOPLifer forum somebody said that there is a relationship between racism and poverty

I asked why the old confederate states were still poor so long after the rebellion?

Sara Robinson replied
They were founded from the get by a specific group of Englishmen who believed utterly in aristocracy — and you can’t be a have without a whole system of have-nots to support you. Southernomics depends on maintaining this hierarchy, and has from the very first. (The layout of any small Southern town tells you all you need to know here: there are usually a very few grand houses around the town square where the people who own everything live; and a whole lot of rickety little cabins where everybody else lives. Inequality has always been vast in these places, and that was by design.)
Their poverty has nothing to do with the war, and everything to do with the worldview that made the war necessary in the first place — a worldview that’s still strong (and spreading) in the US to this day

Moslerfan replied
Demonstrating once again that having 1% of the people hoarding all the money ( and property) does not result in a healthy economy.

As I believe that we have entirely too much inequality I was interested in another discussion on that topic

As far as the south is concerned
The fertile lands and the ease of navigation on the great rivers in the center of the USA should have resulted in the richest part of the country - or am I missing something?

LarryHart said...

I thought it was clear that "dark matter" is cat fur.

Happy New Year, everyone (it's still 2015 in Chicago, but not for long).

It may be an arbitrary date, but for a few hours anyway, it feels as if you can start fresh. I always claimed that calories consumed in the previous year don't count toward your weight in this year. It also has the benefit of being apolitical. Or did I miss the "War on New Years"?

David Brin said...

The winter solstice... back in the 21st... is not arbitrary.

Before the Civil War there WAS a lot of wealth in the South. But cotton monoculture resulted in a feudal society. And regions that have no winter get no winter "reset" re foliage and insects, which overwhelm small farmers.

Paul SB said...

Hi Duncan,

Not a source with verifiable data, just opinion-slinging, but it's surprising opinion slinging, given the context. Maybe there is some hope...

As to fertile lands and navigable rivers, in this day and age these factors are necessary but insufficient.

Paul SB said...

Larry, the dark matter you mentioned is at Grandmother's house. Outside my door you'll find the kind of dark matter left by the neighbor's dogs...

Happy New Year! Don't drink anything you'll regret, at least not very much.

David Brin said...

Happy new year all. And may the great and historically positive 21st Century commence. Though, of course, that's up to us.

DP said...

When talking about colonizing mars, landing on Phobos is a necessary first step for one simple reason: we hae no idea how to safely land a man on Mars.

The Martian atmosphere is too thin for a parachute landing and its gravity is too heavy for rocket landing. To quote fellow SF writer Charlie Stross:

"Landing safely on Mars is hard. The atmosphere is too thin for aerobraking of massive payloads, but thick enough to kick up horribly unpredictable turbulence if you try and use retro-rockets. So for small payloads recent probes have used the bouncy air-bag trick ... but that involves loads of up to 20 gees on impact (not good for humans!) and maxes out at around 1000 kg of payload (or the airbags are infeasibly bulky and heavy). The big sky crane approach is promising (allows retro-rockets while avoiding the turbulence/disruption of landing site effect) but nobody's tried doing it on a payload within an order of magnitude of the size necessary for even an unfueled ascent stage capable of sending an astronaut back into orbit: an ascent stage with fuel on board would be even more massive (on the order of 40-50 tons, minimum)."

20 gees will kill a man.

So we may have to terraform it from orbit before we can land on it.

DP said...

Speaking of terraforming Mars, there are three main methods being discussed: the use of super duper greenhouse gases like PFCs), large orbiting mirrors to concnetrate sunlight, and impacting mars with frozen ammonia asteroids.

And here are also three main deal breakers for Martian colonization: poisonous soils chock full of toxic perchlorates, lack of a protective magnetic field, and the absence of nitrogen as an atmospheric buffer gas aand life sustaining n-cycle.

If you can get it to rain on Mars, the toxics will eventualy wash out of the soil. Establishing an atmosphere will provide most of the protection against radiation. Though a magnetic field would prevent long term loss of atmosphere it could be replensihed as needed anyways.

The big problem is lack of nitrogen. It exists in martian soil and regolith but the energy costs required to release it in sufficient quantities are insanely large. So the nitrogen will have to come from elsewhere in the form of a bombardment of frozen ammonia asteroids. Ammonia is iself a GHG and the impacts will release vast amounts of CO2 and water from MArtian soil. Mirrors and PFCs could be used as adjuncts to this main proces.

How many? Last year I crunched some numbers for a similar terraforming of Venus using hydrogen from frozen water comets via the Bosch process. So here are some quick calculations for the amount of frozen ammonia needed to transform Mars:

1. Earth's Atm. Percent Volume (approximate)

a. Nitrogen (N2) 78.09%

b. Oxygen (O2) 20.95%

c. Argon (Ar) 0.93%

d. Air (with trace gases) 100.00%

2. Molecular weight of components (approximate)

a. Nitrogen (N2) 28.01 kg/mole

b. Oxygen (O2) 32.00 kg/mole

c. Argon (Ar) 39.95 kg/mole

d. Air (with trace gases) 28.97 kg/mole

2. Relative Mass (approximate)

a. Nitrogen (N2) 21.87 kg

b. Oxygen (O2) 6.70 kg

c. Argon (Ar) 0.37 kg

d. Air (with trace gases) 28.95 kg

4. Percent Mass (approximate)

a. Nitrogen (N2) 75.56%

b. Oxygen (O2) 23.16%

c. Argon (Ar) 1.28%

d. Air (with trace gases) 100.00%

5. By Total Mass (approximate)

a. Nitrogen (N2) 3.85E+18 kg

b. Oxygen (O2) 1.18E+18 kg

c. Argon (Ar) 6.55E+16 kg

d. Air (with trace gases) 5.10E+18 kg

6. Martian Atm. mass needed to create Standard Air Pressure (Mars gravity = 0.375 g)

a. Nitrogen (N2) 1.03E+19 kg

b. Oxygen (O2) 3.15E+18 kg

c. Argon (Ar) 1.75E+17 kg

d. Air (with trace gases) 1.36E+19 kg

7. Ammonia Requirements

a. Ammonia (NH3) 34.00 kg/mole

b. Required mass of NH3 1.25E+19 kg

c. Density of frozen NH3 820 kg/m^3

d. Volume of frozen NH3 1.52E+16 m^3
1.52E+07 km^3
8. Relative size of frozen NH3 Volume

a. Radius of NH3 sphere 153.71 km

95.30 miles
(about the distance from New York to Philly)

b. Radius of Ceres 476.00 km

295.12 miles

DP said...

The amount of frozen hydrogen estaimted above represents about 1% of the volume of the asteroid belt. If insufficient ammonia is found in the belt, there will certainly be enough in Saturn's rings or in the Trojans associated with the Jovian worlds.

Mars' atmosphere can be made to retain heat with PFCs, and a orbiting mirrors can be used to generate enough power for a magnetic field:

"A superconducting magnetic loop, wrapped around the Martian equator, can be used, powered up to a magnetic field energy of ~620,000 trillion joules (620 petajoules), by about 12.4 seconds of energy from the solar-mirrors."

locumranch said...

In a manner near identical to Ontological Argument, our physicists have 'deduced' the existence of Dark Matter by first assuming the necessary existence of an invisible, massive & universal organizing principle (heretofore to be referred to as 'dark matter').

Otherwise known as 'begging the question', this unscientific type of circular argument has plagued humanity for generations, and it saddens me greatly to see this type of illogic self-perpetuated by our best & brightest.

A Happy New Year to you all, even though I am less than optimistic as the above argument suggests that humanity possesses only marginal intelligence, and may Dark Matter & the Universal Organizing Principle have mercy on all your souls.


Catfish N. Cod said...

Alfred: In terms of hardware, as much as possible, we should ship modular components easily reconfigurable, and let the Martians kitbash. Complex finished goods are one thing Earth will have to ship to Mars; the other is complex organics -- pharmaceuticals, composites, and suchlike. Fortunately, like spices (also complex and hard-to-obtain organics), these are high value-to-mass ratio and g-resistant.

David: The real bitterness in memories of the Civil War never really was about the Civil War. It was the attempt afterwards to defeudalize the South that the aristocrats and all their toadies hated. Names like "carpetbagger" and "scalawag" didn't come about by accident. There's a certain section of _Gone With The Wind_ that describes this attitude quite well.

Concurrent with that was a deliberate effort to deny the South access to capital and advancement opportunities, or to take Northern ownership of Southern assets. (Example: for almost fifty years after the Wo-ah, Harvard Medical School sent interviewers to all parts of the country and even to Europe and Japan... but not to the South. Descendants of rebels Need Not Apply.) The latter was a massive aid to the aristocrats when they regained control and built the Bourbon and Jim Crow systems; it increased the sense among the middle and working classes that the North hated the South in general, not just the aristocracy.

I can't help but feel an opportunity to prevent or fight the Lost Cause memeplex was missed, there.

Daniel: Terraforming an entire planet to make reentry easier does not seem like an elegant engineering solution to me.

David Brin said...

Daniel, interesting stab at numbers for terraforming Mars. But of course the initial waves will need nitrogen more locally -- e.g. for domed cities -- than globally. Note that in comets the nitrogen is more likely to be in the form of cyanide HCN than ammonia. Note that the lack of plate tectonics on Mars has a silver lining. You can probably pummel one side of the planet with comets while the other side is occupied by settlements. See my new story "Tumbledowns of Cleopatra Abyss" for a tale about raining millions of comets onto Venus, the only conceivable way to terraform it.

Catfish: the Radical Republicans in 1865 should have simply seized 75% of the land of anyone who had owned 3 or more slaves. (50% if they sacrifice the main house and buildings.) All the seized property should have gone into a pool to be distributed among three entities evenly -- (1) a benevolent organization of veterans and widows and orphans, (2) a freedman's bureau to benefit ex-slaves, (3) an education foundation to establish new, equal schools for all.

Had that been done, the average confederate soldier would see his own interest in the confiscation and redistribution. And it is precedented. In the 1780s states seized and redistributed a third of the land in the former colonies.

locum: blah blah does not substitute for actually knowing something. Nor does it make your mind equal to those who are vastly, vastly smarter than you are. Flouncy preening does not make up for incuriosity.

Jumper said...

I've been pondering plot lines for stories of alternate dimensions and seem to have wandered into one, as I tend to agree with locumranch on the dark matter (and dark energy) questions.
One interesting thing about the field of topology is it is not completed. Is there any shape of the universe which would mimic the effect of dark matter?

Acacia H. said...

Why terraform Mars at all?

You can use the material in that ammonia asteroid to instead build a number of hollowed-out asteroids, spin them to allow for artificial gravity, and build up the interior. You even have a shell of a few tens of meters of silicon and other rocky materials to block out the cosmic radiation.

Weather becomes something induced inside the asteroid-base. Natural disasters become far less common (and far more lethal as if you have something hit an asteroid base hard enough to cause earthquakes, you're probably breaking open the shell). And you can even control the ecosystem within it.

Some of these colonies could even be left wild. Inhabit them with endangered from the Earth. Let them build their own ecosystems... and if another colony has an ecosystem collapse, they can take some elements from these reserves to rebuild their own ecosystems.

When the Sun eventually swells to engulf the Earth, there will be billions of these colonies. Some may very well have used solar sails to escape into interstellar space or even head to other stars.

Rob H.

David Brin said...

Amen Rob H.

duncan cairncross said...

Hi Jumper

As I understand it "dark matter" is a solution for the
"why is everything going too fast"

I assume that simple solutions like the "shape of the universe" were examined first and found to be insufficient

One problem with the simple solutions being that the excess speed appears to vary at different locations producing the ability to produce maps of the "dark matter"

Locum is simply ignoring the problem altogether

David Brin said...

The spectacular progress in using intergalactic gravitational lensing has been amazing. Ten years ago, we were marveling THAT there were such lenses, showing us magnified images of very early galaxies 10 billion light years beyond the lensing galactic cluster.

Now astronomers are using these lens clusters as instruments, doing dazzling things like detecting a supernova in an early galaxy's image in an Einstein Cross... and predicting exactly when the same supernova would erupt in one of the other cross images. It's like time travel!

Oh, and they could do this because they used the lens to map the distribution of dark matter in the nearby galactic cluster. We still are murky about what DM is made of. But many of its traits and distributions are unfolding very rapidly, penetrated by publically-funded science costing taxpayers pennies each, pursued by some of the smartest and wisest and most competitive humans our species ever produced.

And jealous carpers won't change that. Cause we will not let the confederacy return us to a dark age.

Jumper said...

I'm for more research.
Neverness, by David Zindell, had an amusing bit in it. In the future scientists have expanded the list of primary subatomic particles to some tens of thousands of verified ones, before it became clear somehow they were barking up the wrong tree. I'm just convinced that humans will last for a long time, and that in 400 years some of what is accepted now will be seen to be hopelessly wrong. It has, after all, ever been so.

Paul SB said...

Jumper, I can't agree more with your call for further research. Few of our most deeply-held "truths" have lasted the test of time, a fact that the professionals of science are well aware of. It is also why the cries of "stuck up scientist" I hear from the ignorant fall on deaf ears, here. Humility is built right into the scientific method. And when people go on about how much money astronomy costs (publically-funded science costing taxpayers pennies each) and how silly it is to use that money to discover things like rocks on Mars, I can only roll my eyes like the permanent adolescents they are. But typically those types are like loci - legends in their own minds who are unwilling to do the hard mental work to become credible, much less legendary. They mostly fail to distinguish between logical and analogical reasoning, and since analogical reasoning is easier, that's what they take for sense. There is a bifurcation in society between those who are willing to learn and those who pretend they already know everything, fighting constantly to defend their egos rather than to understand the real Universe. I don't know if that bifurcation is growing, or if the Internet has just made them more visible.

Paul SB said...

Robert, have you ever read a book called "Kirinyaga" by Michael Resnick? Your idea of asteroid-based ecological preserves reminded me of that. In the preface the author explains that the book originally began as contributions to an anthology that never happened. In that case, though, it wasn't ecosystems they were preserving on asteroids, but cultures. Apparently the idea was that any disaffected group could form their own colony where they could live in isolation from the rest of human society. Maybe this will be the future of Confederate culture, religious extremists of all stripes and any number of throwbacks who can't deal with living in a human society that is not exactly what they want it to be. Unfortunately, while this would be a respite for most of humanity, it might not be such a good thing if these little intolerance colonies are what remains when old Sol fattens up in its senescent years.

DP said...

Robert - "Why terraform Mars at all?"

Terraforming and creating asteroid habitats are not mutually exclusive. If we have the technology and resources to create asteroid habitats we will be able to throw a few ammonia asteroids at Mars.

Still leaves the problem of how to land humans on Mars in the meantime.

At only 38% of Earth's gravity perhaps we can construct a space elevator anchored at Mars' equator using automated equipment controlled by humans based on Phobos.

Or we can land automated PFC factories on Mars that will create enough super GHGs to heat up Mars and generate a sufficiently thick atmosphere (mostly CO2) that will allow for safe parachute landings.

Or we come up with insanely more powerful and efficient rocket engines to allow for landing and take off from Mars' relatively deep gravity well.

Jumper said...

Eventually we'll need drilling rigs for space colonization, especially lunar or planetary, for water. The launch costs are dismaying. I strongly desire Phobos mission first, and would go so far as suggesting semi-permanent manned presence there, Mars has so much to offer though:

David Brin said...

Experiments to search for Dark Matter --

locumranch said...

According to NASA, baryonic matter (aka 'normal matter') makes up less than 5% of the Universe entire, meaning that the majority of our so-called 'scientific' dark matter & dark energy theories are almost entirely non-empiric, non-evidentiary, baseless, unsupported & unsupportable, on par with the old parable of some blind men in a dark room who attempt describe an elephant concealed at a thousand miles distance, which (of course) does nothing to to diminish the awesome beauteousness of either baryonic matter or the Universe entire.

Even so, I will put such skepticism aside if & when these erstwhile scientists come up with something more than a pretentiously non-descriptive name with which to summon with: Dark Matter 2, the ongoing adventures of the Dark Star crew as they bumble their way through cosmological theory complexities, finding 'nothing', with neither talent nor a clue.


Jumper said...

Here's a cold massive object yet observable:

David Brin said...

A frog lectures symphony musicians about Beethoven. One can only tolerate and shrug.

Paul451 said...

Re: Locumranch and dark mattter

Jesus, it's the name that offends him? Wadda ultra-maroon. Wadda im-bess-ill.

Re: Phobos space elevator

It's an old idea. But Hop (Hollister David, occasional poster) just put up a post about it while exploring a new tether spreadsheet someone made, so the idea was fresh on my mind.

It's just so much simpler than a space-elevator to Mars itself. You can get 90% of the benefits with 1% of the material mass. And unlike any planetary space-elevator, a Phobos tether is useful from the first sub-10km tether, through 100km, to thousands of kilometres. You don't need to build the entire ultimate (50,000km) length as the first step.

"Now astronomers are using these lens clusters as instruments, doing dazzling things like detecting a supernova in an early galaxy's image in an Einstein Cross... and predicting exactly when the same supernova would erupt in one of the other cross images."

Not quite exactly, they were a whole year out. Sheesh, bunch of amateurs.

Paul451 said...

Daniel Duffy,
"The atmosphere is too thin for aerobraking of massive payloads, but thick enough to kick up horribly unpredictable turbulence if you try and use retro-rockets."

However, we're learning more about firing rockets into a hypersonic airstream in thin atmosphere, thanks to SpaceX's efforts to recover their first stages. It seems to be pretty simple (as rocket science goes.)

Apparently some of the NASA-Mars guys have been all over them with instruments and high-end monitoring, since it's the first time anyone has actually done the experiment. It had become a defacto facto amongst higher-ups that it was probably impossible (too unstable) and therefore not even worth trying.

Which is one of the many insane things you discover about the behind-the-scenes politics of the space program when you start drilling down. There are so many weird myths believed by higher-ups that are either proven untrue, or have never been tested, but whenever someone proposes a demonstrator to test the theory, they can't get funding because "everyone knows" it won't work.

[For example, the entire idea behind SLS is based on the myth that Earth Orbit Rendezvous (EOR) architecture is too risky or expensive or... something; even though docking is so routine they are handing it off to commercial vendors. So you have a program that will spend upwards of $70 billion and waste two decades on building a launcher large enough to avoid the need to developing an EOR booster stage or orbital-depots, even though every component in every SLS mission proposed so far has been within the payload capacity of existing launchers - provided you launch them individually.]

Paul451 said...

Daniel Duffy,
"So we may have to terraform it from orbit before we can land on it."

OTOH, if you are going to terraform Mars, the people on the ground are mostly going to be in the way. The best, cheapest, path to terraforming Mars is to avoid Mars like the plague.

Aside, the first fossil signs of free oxygen production on Earth goes back to 3.5 GYA. For 1.5 billion years it was all absorbed by the ocean. (AKA "the Great Oxidation Event".) Only then was it released in the atmosphere and started to oxidise the land. That took another nearly 1.5 billion years. (AKA "the boring billion".) Suddenly, somewhere around 3/4 GYA, oxygen levels in the atmosphere suddenly shoot up to 10%. (I mean "suddenly" on the scale of billions of years. It probably took ten-to-twenty million years.)

3 billion years of oxygen production just to saturate the land and oceans.

But we're going to terraform Mars?

Rob H has the right idea. Any technology and scale of industry that allows us to (sort-of) terraform Mars is an order of magnitude more effective in places like the asteroid belt. And it's inherently more robust. (Oh, each asteroid or free-flying colony is more vulnerable than an entire planet, but the whole ecology (we need a new word) is vastly more robust.)

We don't have a need for simple acreages of raw land. Especially not dead land. We want a self-sustaining industry. Mars doesn't deliver that, instead it just sucks up the resources (and attention) that would be better spent looking for opportunities elsewhere.

Jon S. said...

Those perchlorates in the Martian liquids - are they there in sufficient quantity to justify drilling them out and refining them for rocket fuel? Could Mars become the Saudi Arabia of space (probably minus the genocidal tyrants in charge)?

Eh, probably not, but it's fun to think about.

Tim H. said...

Back to dark matter, I think a lot of the controversy arises from the provisional nature of science, which gives a picture of life, the universe and everything, subject to new research. This is a difficulty for critics of some findings, and researchers protecting their work, it's difficult for both groups to grasp that the provisional nature is a feature, not a bug. Sucks to be the one whose research is overturned, but it's better for the entire community to have a more accurate picture. If you don't like the current body of knowledge, wait, it'll be clarified.

Charlie Hohn said...

Too bad about hydrogen fuel. I didn't realize there were so many problems with it. I thought we could just use electricity to break hydrogen out of water, then "burn" it which would just release water again. I did not know there are other toxic things involved...
Definitely agree that it would be good to break free from the gas station thing though that sounds like it may not be easy to do

Acacia H. said...

Oh, you can. The thing is, the amount of energy used to break the hydrogen-oxygen bonds is rather high, and that energy can be used in other processes. If you use coal to break the water into its elemental components, you are causing far more pollution than what was saved in not using gasoline-powered cars. That is before you include the energy costs of compressing and/or liquefying the hydrogen.

Certain elements can be used in the electrodes which help catalyze breaking the hydrogen-oxygen bonds. Those catalysts are often toxic and can be expensive.

It is far more efficient to use batteries instead of hydrogen power. And a hydrogen fuel cell doesn't "burn" hydrogen to power an engine - it uses the hydrogen to generate electricity to power electric motors... much like an electric battery, only with a fuel source.

Rob H.

locumranch said...

In magical circles, knowing the complete and true name of an object, being, or process was once thought to give one complete control over it. This was thought to work because (1) a name is a definition, (2) a contagion link, (3) a similarity link and (3) an association. To this day, many magical thinkers still insist that knowledge of a 'true name' gives one a complete understanding and some measure of control over that particular process, situation or thing; hence our incessant jingoism, the proliferation of jargon, non-definitional labels and meaningless terminologies which tend to be nonsensical, misleading & obfuscational.

Progress; diversity; dark matter: Terms like these are mere incantations that neither describe nor define. At best, they signify membership in an exclusive club. At worst, they stifle critical thought, dissent & empiric inquiry.

As far as Frog Symphonies go, you can tell the ones with the PhD's by their coordinated croaking, distended chests & cute little bow ties:


LarryHart said...


Even so, I will put such skepticism aside if & when these erstwhile scientists...

Former scientists?

DP said...

Space Solar Power Satellites remain the only reason for industrializing space.

Space tourism remains a tiny niche market for the ultra rich.

Space manufacturing (outside of materials that absolutely have to be manufactured in zero gee) has no cost or quality advantage over terrestrial manufacturing.

Asteroid mining to feed Earth markets makes no economic sense. Suppose an asteroid mining operation found an asteroid of almost pure platinum (current spot value of about $890 per ounce) and hauled it back to Earth orbit. How is it going to get this material down to the Earth's surface without expensive rentry vehicles? And a large enough platinum asteroid will certainly depress market prices through over supply, making the asteroid mining of platinum unprofitable. It's an unavoidable catch 22. (Not to mention it won't be competitive with mining nodules off the sea floor)

The only kind of space industry that can benefit Earth has to one that supplies something immaterial: energy or knowlege. And while a geological survey of Mercury's regolith is fascinating and useful for pure science it won't have much market value. So that leave us with energy.

Asteroid mining can provide the materials needed to build orbiting mirrors and lenses to collect and focus sunlight. In space these lenses and mirrors can be made to massive size:

"Large lensing structures may not be something of the far future. There was a 2007 NASA NIAC study for making large bubbles in space. Devon Crowe of PSI corporation made a study for making large space structures from bubbles that are made rigid using metals or UV curing. A single bubble can be 1 meter in earth gravity, 100 kilometer in low earth orbit or 1000 kilometers in deep space. Foams made of many bubbles could be far larger in size. The size of a 1000 kilometer bubble is nearly the size of Charon, the moon of Pluto. Charon is 1200 kilometers in diameter. Saturn's moon Tethys is 1050-1080 kilometers in diameter Ceres the largest object in the asteroid belt is 970 kilometers in diameter. A single tesselation foam (like in the picture) of 1000 kilometer bubbles would be about the size of Earth's moon. A Penrose tesselation like the one in the picture of 1000 kilometer bubbles would be in between the size of Neptune or Saturn. A Tesselation foam of 100 kilometer bubbles in earth orbit could form an object the size our existing moon or larger. Metal can be evaporated to coat the inside of the bubble for reflective sails and telescopes."

These lenses and mirrors can be separate structures in synchronous orbit with the actual generators, probably Stirling engines in low earth orbit. The resultant energy can be beamed down to rectennas on the surface.

Aside from solar power, here is no other economic reason for developing space industries.

David Brin said...

"coordinated croaking"? Sorry. The guy's just to hilarious! He clearly never met an actual scientist and swallows the koolaid that the enemies of confeds -- scientists - are LIKE confeds... marching conformist-nodding coordinated (by Fox) dittoheads...

,.... instead of by far the most individualistic and competitive humans our species ever produced.

Croak, oh dittohead frog. The one thing he'll never ever do is go and actually meet a real scientist.

David Brin said...



Hop David said...

Thanks Paul451. I just did a post on the upper Phobos tether.

I am obsessed with Phobos. I believe it will be the most valuable piece of real estate in the solar system.

Catfish N. Cod said...

David: "the Radical Republicans in 1865 should have simply seized 75% of the land of anyone who had owned 3 or more slaves. (50% if they sacrifice the main house and buildings.) All the seized property should have gone into a pool to be distributed among three entities evenly -- (1) a benevolent organization of veterans and widows and orphans, (2) a freedman's bureau to benefit ex-slaves, (3) an education foundation to establish new, equal schools for all."

It would have been better than the nastiness that actually happened, where the de-feudalization was executed haphazardly and often with massive private profiteering and corruption. The Freedman's Bureau was grossly underfunded and frankly a joke -- not really surprising as most of the Unionists who actually fought the Civil War didn't care about African-Americans as long as they were not part of a massive economic-political engine threatening their way of life.