Life on Mars?

 

Life on Mars? This tiny South American mouse might hold the answer

[Hmmm.  Maybe not.]

From Melbourne's The Age newspaper

There was a reason biologist Jay Storz braved 21 volcano summits in two years, battling bouts of altitude sickness and fissures belching sulfuric fumes.

That reason lay nestled next to a pile of rocks at the 6000 metre-high summit of Volcan Salin, a mountain on the Argentina-Chile border – a mummified mouse.

The Mars-like flanks of Volcán Salín in northern Chile, which researchers scoured for signs of life.CREDIT:MARIO PÉREZ MAMANI

For years Storz, an expert in high-altitude biology from the University of Nebraska, had chased evidence that mice live on the cloud-splitting peaks of South America’s mountains, thousands of metres above what was considered the altitude threshold for long-term mammalian life.

The freezing, dry, low-oxygen environment is one of the habitats on earth most similar to Mars, and the discovery of the mummified mouse – reported in Current Biology – has redefined our understanding of the physiological limits of mammals.

So what can we learn from these mummified mice about our search for life on Mars?

After stumbling upon their first mouse mummy, Storz and a colleague started searching through a nearby rock pile and uncovered seven more cadavers.

They found another five mice – mummified by the thin atmosphere and extreme cold – while trekking to other volcano summits across the Andes.

There was a chance the mice were ferried to those heights by the ancient Incas, who once performed ceremonial sacrifices on the peaks.

But radiocarbon dating revealed the oldest mouse mummy was 350 years old, and many had died only in the past few decades.

Researchers set traps and captured live specimens, proving populations of Punta de Vacas leaf-eared mice roam more than 6700 metres above sea level. Previously, anything higher than 5200 metres was considered a mammalian no-go zone.

Extremophiles are usually bacteria, but you could say the leaf-eared mouse – found far above the normal mammalian altitude threshold – has joined the ranks of microbes that live in permafrost and radioactive waste.CREDIT:MARCIAL QUIROGA-CARMONA

“Well-trained mountain climbers can tolerate such extreme elevations during a one-day summit attempt, but the fact that mice are actually living at such elevations demonstrates that we have underestimated the physiological tolerances of small mammals,” Storz said.

“The most surprising thing about our discovery is that mammals could be living on the summits of volcanoes in such an inhospitable, Mars-like environment.”

Creatures that thrive in toxic, acidic, radioactive, anaerobic, searing hot or deadly cold habitats – called extremophiles – rewrite biologists’ understanding of life on earth and the sheer force of evolution. But another group of researchers pay attention, too: astrobiologists.

These scientists scrutinise how life may have sprung up on Earth and where it could be lurking elsewhere in the universe.

“You might classify these mice as a type of extremophile,” says Dr Albert Fahrenbach. He’s the director of UNSW’s Australian Centre for Astrobiology, the only centre of its kind in the country.

Fahrenbach’s colleagues have scoured the globe for the most alien environments to help them deduce what we might find on seemingly barren exoplanets.

For example, the centre’s Professor Belinda Ferrari discovered bacteria in the soil of hyper-arid deserts in Antarctica, where there’s little available water or organic carbon, and the sun can vanish for months, precluding photosynthesis.

The bacteria were consuming hydrogen, carbon dioxide and carbon monoxide, generating energy and water to stay alive – essentially, living off thin air. Their discovery provided a new model for how bacteria might thrive on harsh alien planets, nourished only by the atmosphere.

Each time scientists discover an extremophile – from the high-altitude mice to air-eating bacteria – our limited ideas about what life might look like beyond Earth expands, boosting our chances of recognising habitats on other planets that may sustain alien organisms.

In June, another of the centre’s astrobiologists, Professor Martin Van Kranendonk, led NASA personnel through the red dust of the Pilbara in the north of Western Australia to show them stromatolite fossils.

These swirls of dark silica, produced by prehistoric cyanobacteria, date back 2.7 billion to 3.5 billion years – the oldest confirmed evidence of life on Earth.

In 2007, the Spirit rover stumbled across similar silica structures in the Columbia Hills of Gusev crater on Mars, Fahrenbach says.

In particular, the structures resembled microbe-produced silica deposits found at the edge of the Atacama Desert in Chile – another landscape used as a proxy for Mars that isn’t far from Storz’s mummified mice.

Silica deposits found on Mars in 2007 compared with silica deposits in Chile, which were shaped by microbes.CREDIT:LIFESPRINGS MARS

“To the untrained eye, they just look like some unusual rock,” says Fahrenbach. “They have these really crazy textures, but from a geologist’s point of view, they’re pretty easy to identify as arising from life.”

The Martian structures, too, could yield biosignatures – evidence of creatures once alive on the dusty red planet.

“There’s only one way to be sure – to bring a sample back and study it on Earth, to see if we can provide evidence that these structures were generated biologically, ” says Fahrenbach.

The LifeSprings Mars mission, led by Van Kranendonk, aims to retrieve that all-important Martian sample for testing. According to the researchers behind the mission, it’s “humanity’s best chance to search for extraterrestrial life”.

But even as our knowledge of earthbound biology expands, there’s always the chance alien life is so beyond our current imagination we’re looking in the entirely wrong places, Fahrenbach says.

“There could be life out there that’s not based on any chemistry that we recognise.”

A very interesting article.  

However, Mars has even more extreme conditions than on top of a Chilean volcano.  Mars's average temperature is -60 degrees C.  The average air pressure is just 6.1 millibars, which reaches 11.6 mbar in Mar's deepest crater, Hellas Planitia.   Even at 6000 metres altitude, air pressure on Earth is 472 mbar.  In fact, Mars's air pressure is so low, the blood in your veins will boil.  If air pressure is below the Armstrong Limit (62.5 mbar) water will boil at body temperature.  At the summit of Mt Everest, your blood might not boil, but air pressure is so low (337 mbar) that your lungs can't absorb enough oxygen from the atmosphere, and you die of hypoxia.   Mars is a long way from habitable even by a miracle mouse from Andes volcanoes.

But the extremophile organisms discussed in the article might well be useful as we terraform Mars.  If we ever do,

"Relatively low cost" plan to cool the poles

From New Atlas

New research suggests that cooling the poles by 2 °C (3.6 °F), and re-freezing the Arctic and Antarctic, is "feasible at relatively low cost with conventional technologies," using Stratospheric Aerosol Injection (SAI) of heat-reflective particles focused on the poles. The side effects could be nasty, and the politics near-impossible, but the plan offers a way to slow, or reverse the catastrophic sea level rise projected as polar ice collapses.

SAI is an enormously controversial idea inspired by the cooling effects that tend to follow large volcanic eruptions. These natural events eject vast amounts of dust, ash, and often sulfur dioxide into the air. The first two create a shade effect that causes a short-lived cooling effect for a couple of hours, but sulfur dioxide tends to rise high into the stratosphere, where it combines with water molecules to create sulfuric acid particles, and remains for up to three years, reflecting solar radiation away and causing a long-lasting surface cooling effect.

So the idea behind SAI is to load up high-altitude aircraft with sulfur dioxide, and fly around spraying it into the atmosphere at high altitudes, mimicking the cooling effect of a volcano. So far, so good. Mind you, the way that sulfuric acid eventually leaves the atmosphere is by combining into larger and larger droplets that eventually become heavy enough to fall down to earth as acid rain, which is, as you'd imagine, not great for plant life, fish or animals. And all sulfur oxides are nasty to breathe in, harming the lungs and causing asthma and bronchitis if inhaled regularly.

To date, most SAI research and modeling has focused on spreading these aerosol deployments all over the globe. But there's a growing number of scientists starting to look into just doing it at the North and South Poles. The Arctic and Antarctic are feeling the effects of climate change far worse than the rest of the world at this stage; they're warming several times faster than the global average, causing colossal ice structures to collapse and melt. Every climate model factors in the resulting rise in sea levels, which will have catastrophic effects all over the world.

To state the obvious, no scientist wants to fill the air with sulfur, drench the last remaining polar bears and penguins in acid rain, or give carbon emitters any excuses not to clean up their act. But faced with our current trajectory, on which summer sea ice in the Arctic will more or less disappear by 2050 or earlier, humanity finds itself between a rock and a hard place. All options need to be on the table, evaluated, and to some extent ready to go early enough to make a difference.

So research into SAI is progressing quickly, and concentrating it at the poles – an approach referred to as subpolar deployment – may deliver better returns for significantly less money and acid rain than a global model. Prior research has indicated that spring and early summer is likely the most effective season to do it, and that only doing this at one pole could have asymmetrical effects on global weather, so it's probably prudent to target both, with a fleet of planes that travels with the seasons.

A new study from a fairly broad range of contributors digs into what a bipolar SAI program targeted at "refreezing" the Arctic and Antarctic might look like, what it'll cost, and where the equipment and technology gaps might be.

The study proposes a nominal target of cooling the North and South Poles by 2 °C (3.6 °F), noting that Arctic temperatures have already risen by more than 3 °C (5.4 °F) over the last 50 years. It proposes that the aerosol injections be made at the 60th parallels, roughly the latitudes of Oslo, Helsinki, Homer, Alaska and Magadan, Siberia in the Northern Hemisphere, and level with the southern tip of Patagonia in the Southern Hemisphere. At these latitudes, it's possible to get the job done cheaper, since the troposphere sits at a lower altitude and your aircraft don't have to fly so high. This study chooses an altitude of 13 km (42,600 ft). The particles released would drift slowly toward the poles, concentrating their effects.

To achieve a 2 °C result, the plan would inject 6.7 teragrams (6.7 billion kg/14.8 billion lb) of sulfur dioxide per year into each pole, calling for an eye-watering total of 13.4 teragrams (29.5 billion lb) of material annually.

The study goes on to look at logistics, finding that existing aircraft can't carry enough payload to a sufficient height to get the job done. The closest we've currently got are military air-to-air refueling aircraft, but these can't reach the target altitudes without significantly reducing their payloads. The McDonnell Douglas KC-10 Extender, for example, could get up into the spray zone carrying some 128,801 lb (58,400 kg) of payload, but that's just 22% of the payload it's designed to carry, so you'd be carrying a lot of excess weight on every flight.

The study proposes instead a purpose-built stratosprayer called the SAIL-43K, a downgraded version of an aircraft previously specified to fly higher SAI missions closer to the equator. This machine would carry 167,971 lb (76,190 kg) of payload each mission, but its takeoff weight would be some 77,000 lb (35,000 kg) lighter than the KC-10.

To hit the cooling target, this project would need 125 purpose-built SAIL-43Ks, flying a total of 1,458 missions per day during the four-month injection period at each pole. These planes would take off, climb for 30 minutes, vent their entire load of sulfur dioxide within two minutes, then come back down over the following 30 minutes, and spend the next hour loading up again and refueling for the next mission.

In the Northern Hemisphere, there are plenty of airfields suitable for these kinds of operations; virtually the whole 60th parallel falls on land. In the south, things get a bit more fraught as there are really only a few airfields in Southern Patagonia with appropriate runways. These sit at latitudes closer to 54°, but the team calculates they'll get better results just venting the sulfur dioxide at that latitude than flying some 490 nautical miles south to hit 60°.

These airports would need to be upgraded to handle a total of 110 operations per hour, or a little more than the world's busiest current airport – this will be an enormous undertaking in the Southern Hemisphere, since there are so few airfields to start with in Patagonia. This huge infrastructure job would likely take about as long as developing and manufacturing 125 aircraft – about 15 years after making a decision to go ahead with the plan. This, in itself, is hardly a quick or complicated part of the process, and would require some degree of global agreement on a plan that would disproportionately affect people living in the latitudes in question.

In terms of money, the "relatively low cost" of this project would be around US$11 billion a year (2022 dollars), says the team. This might sound like a lot, but it's about a third of the price of a global SAI effort with the same cooling target, and the researchers note that "relative to other possible strategies by which to combat either the impacts or causes of climate change, SAI remains extraordinarily inexpensive."

While calibrated to drop polar temperatures by 2 °C and to begin re-freezing sea ice at the poles, this project will have a number of unwanted side-effects. The researchers note that the sulfur compounds added to the stratosphere may impact ozone concentrations through a number of different effects, and may thus slow or reverse the recovery of the Antarctic ozone hole. It notes that the effects of teragrams of sulfur dioxide and the associated acid rain deposits are risky both to humans and to the wider ecosystem, requiring lots more research. And it expects some stratospheric heating as well.

Furthermore, the planes themselves can only operate by burning jet fuel, using today's technologies. This annoying fact, plus the emissions involved in building out all the required infrastructure on the ground, plus the emissions involved in preparing sulfur dioxide, mean that a polar SAI program would have a pretty damn hefty carbon footprint of its own, although this would only represent a "marginal" increase to overall aviation sector emissions.

Still, the researchers conclude that "while it has yet to be established that the physical or societal impacts of any SAI program would prove to be net positive, it seems clear that a program focused on substantially cooling the world's polar and subpolar regions would be logistically feasible. This could arrest and likely reverse the melting of sea ice, land ice, and permafrost in the most vulnerable regions of the Earth's cryosphere. This in turn would substantially slow sea level rise globally."

So, short answer: yes, we can re-freeze the poles, while minimizing the risk to the bulk of humanity and agriculture. But we'd need the entire world to agree that sea level rise is a worse outcome than the effects of a massive SAI program, especially for the estimated 1% of the population that lives in the areas where the effects will be concentrated.

"There is widespread and sensible trepidation about deploying aerosols to cool the planet," says Wake Smith, lead author of the new study, in a press release. "But if the risk/benefit equation were to pay off anywhere, it would be at the poles. Game changing though this could be in a rapidly warming world, stratospheric aerosol injections merely treat a symptom of climate change but not the underlying disease. It's aspirin, not penicillin. It's not a substitute for decarbonization."

The study is open access in the journal Environmental Research Communications.

Source: Institute of Physics via Phys.org

Mankind has dithered and delayed so long in acting on climate change that there are now no safe methods to undo the damage.   The fact that we even have to think about it is an indictment of those denialists who, obedient to their fossil fuel paymasters, have so poisoned the well that we've delayed decades before acting.  And remember, emissions are still rising.  Temperatures are still rising.  It's not getting better.

20 Things which will change the world by 2040

Here are 20 things in no particular order which I think will totally change the world over the next 20 years.

1.  CHEAP ELECTRICITY

 Wind costs are falling by 5-10% per annum, solar by 10% to 20% and batteries by 15% plus.  Wind's cost declines will prolly slow over the next 10 years—it's a mature technology.  But the cost declines in solar are likely to continue, and in batteries, there's a real chance they'll accelerate.  If these trends continue (and why won't they?), in 10 years electricity will cost 25% of what it does now.  If the trend decline then halves to, say 7% a year, then in 20 years, electricity will cost just 10% of what it does now.  Cheap energy supercharges economic growth.  The low oil price from 1945 to 1973 helped drive rapid and sustained growth in the world economy.  Cheap renewables will do the same over the next 20 years and beyond.

2.  EVS

They're going to be cheaper than ICEVs (internal combustion vehicles) to buy, and much cheaper to run.  They'll be replacing ICEVs  so the shifts in society might not seem dramatic.  But with AIs running them, transport as a service will become common.  You'll summon a car using your phone, and it will drive itself to where you are and then to where you want to go.  Because EVs will last much longer than ICEVs and will be significantly cheaper to run, "transport as a service" will be a popular way for people to get around.  Car sales are likely to decline by 50% plus, as TAAS takes off.  Air pollution in cities will end.  By 2040, most of the world's vehicle fleet will be electric.  Maybe hydrogen fuel-cell, but I doubt it.  The cost of building a hydrogen refuelling network will be much more costly than just attaching your car to an already existing network, the electric grid.  And the energy efficiency of the hydrogen cycle is much lower than batteries.

3.  AI

I don't think we'll have true AI, as in sentient robots.  But we will have very sophisticated computerised control systems, such as those which will allow for self-driving cars and self-landing rockets.  This has been made possible by the 5 or 6 orders of magnitude decline in the costs of and size of super computers, as Tony Seba points out.  SpaceX's ability to land and re-use its rockets would not have been possible without the advances in computing power.  These advances and changes all interact.

4.  3-D PRINTING

This cuts the cost of manufacturing metal things by at least half, because there's much less scrap.  It also reduces the stock of parts you have to keep on hand.  And allows you to make more complicated things, like SpaceX's extraordinary new Raptor rocket engines.  On the ISS, there is a 3-D printer to make spare parts.  On Mars, and the Moon, 3-D printers will be used to build habitats; to make things which would take too long or are too expensive to get from Earth; and to make things which have short production runs or are experimental.

5.  VAT MEAT, MILK AND FISH

Cheap energy will change agriculture.  Right now, 20% of Australia's tomatoes come from a factory in the semi-desert in the north of the State of South Australia, using desalinated sea water and growing the tomatoes in greenhouses.  This undertaking uses no fossil fuel at all.  Animal rearing  uses vast areas of land, is highly polluting, and contributes 20% to global CO₂ emissions.  Vat meats and fish are already starting to take off.  Their costs are declining year by year.  By 2040, they will become the norm.  

There won't be "real" meat on Mars or on the Moon or in Space Stations .  There just aren't the resources to grow it.  If vat meat, fish and milk taste like the real thing, cost about the same or less, are environmentally kinder, and involve no animal suffering, why wouldn't you switch?  This will reduce emissions by 20% while allowing the rewilding of unused fields and grasslands.

6.  CHEAP ACCESS TO SPACE

Cheap access to space will change everything.  To settle Mars, we'll need to rapidly improve a whole range of technologies, like vat meat production, genuine air conditioning (meaning far more than just heating and cooling), hydroponics, water purification, extracting CO₂ from the atmosphere, genetic modification, medicine, and so on.

By the time SpaceX's Starship is running, SpaceX will have cut the cost of launching a kilogram to LEO (Low Earth Orbit) from $22,000 to ~$20.  Whenever you have a 10-fold decrease in costs you get disruption, as new technolgies take off.   This will be a 1000-fold decrease in cost.  We're already seeing the consequences of cheaper launches in the roll-out of SpaceX's Starlink super fast internet.  The development of a space-faring civilisation will spawn new technologies we haven't even thought of.  Who would have thought 20 years ago that we would carry computers in our pockets millions of times more powerful than the first IBM computer, computers which connect us to a massive knowledge network as well as news, videos, maps, Wikipedia?   None of that was predicted.  Yet think of the businesses which have developed because of those twin inventions, the smart phone and the internet (Apple, Google, Uber, Air BnB ....).  And think also how the explosive growth of smart phone sales also drove down li-ion battery prices,  allowing EVs and grid energy storage to happen.

7.  ASTEROID MINING

With cheap access to space also comes asteroid mining.  Because the asteroids aren't in deep gravity wells like the Earth or Mars, nudging them into orbits which intersect Earth's or Mars's will be cheap.  The resources of a single medium-sized  asteroid, for example for rare earth metals, will more than equal all the rare earth metals that have ever been mined on Earth.   We will prolly stop stripping the Earth to produce metals and minerals and instead start disassembling asteroids to do that.  The world's major resource companies will be asteroid miners.

But some of these will be used in space manufacturing.  Why take stuff into the gravity well when you can build it in LEO?  Asteroid mining will be even more important on Mars, as asteroids will likely provide the volatiles needed to give Mars an atmosphere dense enough for humans to work in without needing to wear pressurised space suits. 

8. BECOME A MULTI-PLANETARY SPECIES

Our first colony will be Mars.  Read  the Red Mars trilogy to see how colonising Mars will change Earth too.  Not just in technological advances but also in social advances.  Looking down on Mars and Earth from space will change mankind's perception of itself.  As Robert Zubrin says, knowing that there is no shortage of resources because we have unlimited resources in space means that most of the causes of war on Earth will disappear.  Of course, no matter how technologically advanced and prosperous humans become, there is no reason to suppose we will ever be more intelligent, less venal, less greedy, and less petty. 

After we colonise Mars, we'll start on Venus.  That'll be much harder.  But by then we will also have colonies in the asteroid belt and large inhabited space stations in orbit round the Earth and Mars.  We will truly be a multi-planetary species.  And that will change everything.

9. TRULY GLOBAL HIGH-SPEED INTERNET

SpaceX's Starlink has kicked off a revolution in high-speed internet.  Starlink's network will be truly global, available in the Arctic and Antarctic,  the Sahara and across the world's oceans.  In countries where wired internet is only available in cities, such as most of Africa, Starlink will provide links to remote villages and towns.  It'll be expensive ($100 per month), but villages could club together to pay for it.  Those same villages are off the electric grid, too, and small solar panels and batteries will change that.  Children who do their homework by candlelight will now be able to do it by LED light, and access the internet, connecting to the ginormous encyclopedia which is the interweb.  20 years ago we didn't have Wikipedia.  Today, even if your village doesn't have a library, even if you  can't afford to buy a book, you'll still be able to study science, maths, languages, technologies.    

10.  TERRAFORMING THE EARTH

The current fall in emissions isn't rapid enough to prevent a rise of more than 1.5 degrees C, maybe even 2 degrees C,  in global temperatures.   We will need to remove CO2 from the atmosphere.  One way would be to cover desert and semi-desert areas with forests.  To do this would require desalination plants, powered by solar, which will get cheaper and cheaper over the next 2 decades.  It would be a mammoth undertaking, almost beyond our imagination.  But it will prolly be necessary.  Given the scale of the problem, any de-carbonisation method will have to be massive.  But something will have to be done to remove CO2 from our atmosphere.  Changing a planet's climate to make it more livable is called terraforming.  You might also call it geo-engineering.  Whatever; we will prolly have started to do it by 2040.  We will have no choice.


11.  GENE THERAPY & GENETIC MODIFICATION

The colonisation of Mars and the growth of space travel will accelerate the development of gene therapy, because radiation on Mars and in space will cause genetic damage.   Treating that will become imperative, and as technology often responds to extreme need, it will likely be developed, because it has to be.  Gene therapy will provides cures for cancer, diabetes, heart disease, and inherited genetic diseases like cystic fibrosis. 

Creating plants which will grow in our domes on Mars and on space stations to provide us with food will be important to the pioneers.   Dwarf wheat, larger tomatoes, low-rise almond/fruit trees, and so on and so on.  The need for these advances will drive rapid change.  But the advances themselves will drive down the cost of food back here on Earth.  


12.  THE RISE OF AFRICA

Africa is the second-largest continent, in population and size, compared to Asia.  For decades, Africa has been an economic laggard.  But solar favours countries near the equator.   Seasonal storage needs are much less than in high latitudes further from the equator.  8 hours of storage will be enough for most places within 30 degrees north and south of the equator.  Cheap electricity will be even cheaper in Africa.  In addition, Africa's population is young, it speaks English as a first or second language, and it's so far behind the production possibility frontier that high speed internet and distributed solar power will be transforming.    

Until recently, Africa has lagged the world economy, but access to electricity and information will change everything.  Africa will be the new China, with high growth rates, falling poverty and  rapid development, and with that will come greater political power.  China has recognised this reality; the rest of the world has not.  That needs to change.


13.  THE END OF NEO-LIBERALISM

Neo-liberalism has been tried for 40 years.  It has resulted in greater economic and financial instability, and vastly increased inequality of income and wealth (especially in those mostly Anglophone countries which have most enthusiastically embraced it), as well as a lower growth rate.   The rising inequality has also led to increased political extremism.  Economists like to pretend that economics is separate from politics.  But the consequences of increased inequality and greater uncertainty have shown that there is a non-economic price for neo-liberalism: the rise of far right parties and policies. The dogma of small government, low taxes, and deregulation is becoming tarnished.  The Covid crisis has conclusively shown that there are some things government does better than the private sector.  Unlike the neo-liberal dogma, the private sector doesn't inevitably do things better and more cheaply than the public sector, especially when second order effects are considered.  Privatisations of state-owned enterprises have mostly failed: costs are higher, services no better, corruption worse.

Expect a gradual retreat from the extreme tenets of neo-liberalism towards a more measured and pragmatic process.  Big(ger) government is back.  The big borrowings government took up under Covid are not going to be repaid.  Instead, governments will start running deficits again.  The post WW2 pragmatic neo-Keynesian synthesis will once again modify red-in-tooth-and-claw capitalism.  

14.  A UNIVERSAL BASIC INCOME

Technological advances will cause major disruptions to job markets.  So will shifts in economic growth and development.  In the past, dire poverty among the old was reduced by the introduction of a universal basic income or social wage for old people, otherwise known as the old age pension.  A UBI in developed countries, for everyone, has so far been seen as a step too far.  But opinion is changing.  If we are truly to drain the poison of the extreme right, we will need to address the insecurity and poverty of the precariat, which will likely be worsened by the technological and economic changes I think will happen.   A UBI would do that.

15.  HYPERSONIC INTERCONTINENTAL FLIGHTS

SpaceX would like to use Starship to run suborbital long-distance flights.  Musk has said that over long distances, suborbital flights will have a lower cost than conventional jet travel.  At 20 times the speed.  Anybody want to bet it won't happen?

16.  NEURALINK

Musk is afraid that a real AI (as opposed to very clever software) would end up ruling the world and humanity would end up being no more than pets of the machines.  If we even survive.  His response to that is to develop brain-machine interfaces.  This would make us as clever as our AI overlords.  We would have chips in our brain, like a permanently embedded smartphone.  It might never get to that, but if an interface can enable a blind person to see again, or a disabled person to walk, then that would be huge.  And having a small device in your head which allows one to communicate directly with the interweb would be revolutionary.  Not sure I like the security implications of that, though.

17.   ELECTRIC PLANES

We will soon see the introduction of electric planes which will allow short flights (up to 400 km) at 1/20th the cost of jet or jet-prop aircraft of today.  They will be used to connect outlying regions to the spaceports where suborbital ultrasonic flights will depart from and arrive at.  The long-term outlook for conventional airliners isn't good at all.  What these two developments mean together is that one will be able to fly from a small town in the bush to another small town on the other side of the world in a few hours.  A hundred years ago, it took 3 weeks for a ship to sail from Australia to Europe.  Currently, it takes 24 hours to fly that distance.  With suborbital hypersonic rockets, the journey time will be down to just an hour.

18.   NUCLEAR FUSION

Nuclear fusion is the opposite of nuclear fission, where large atoms, e.g., uranium, are split into smaller atoms, releasing massive amount of energy.  Fusion is what happens inside stars like our sun, where the lightest atoms, hydrogen, are blasted together under intense heat and presure to produce heavier atoms.  And therein lies the difficulty--it's very hard to create those conditions outside the fiery heart of a star.   For 70 years, the joke goes, nuclear fusion has always been 30 years away. But maybe that's changed.  Fusion is likely to make much faster progress now that private firms and individuals are bankrolling research than it has under the aegis of giant bureaucracies, so I think we'll prolly have fusion by 2040.  We will need nuclear fusion on Mars, and to mine the asteroids.  And it will be enormously useful on Erarth, too.

19.  A RETURN TO DEMOCRACY

Winston Churchill said that democracy was the worst system, apart from all the others.  People have pointed to the Chinese and Russian dictatorships as exemplars of how to run politico-economic systems.   Yet both countries have declining growth rates.  This is particularly interesting in the case of China, which is far from being a wealthy country, and where you would expect growth to remain higher than it is, given where it is in the typical development pathway.  For all America's faults, and despite the out-and out dementia of the Right and the Republican Party, the technological developments there are breathtaking.  Perhaps people need freedom if they are to innovate.  Just a thought.  

If we drain the pus of divisiveness and far-right toxins from our democracies by reducing inequality, and again giving ordinary people hope that their lives and the lives of their children will be better, I believe that the autocratic political/social/ economic alternatives of China and Russia will be seen as what they are: relative failures.

20.  SYNERGY

All these changes will interact, just as smartphones and internet did, the one driving the development of the other.  And the interactions will spiral out of control unforecastably. changing the world in ways which will surprise and shock us.  And some of the consequences will be adverse.  But it's going to be a most interesting ride.

Living on Mars - IV

There are numerous difficulties with living on Mars.  I've talked about them before (see list of related pieces below).  These are the three most serious:

• Radiation, from the sun and from outer space
• Very low temperatures (-60 C on average)
• very low atmospheric pressure (6 mbar compared with roughly 1000 mbar (millibar) at sea level for Earth)

The obvious solution is to give Mars an atmosphere.  If the atmosphere is thick enough, temperatures will rise (Earth's temperature is roughly 33 degrees C higher than it would be without an atmosphere).  An atmosphere will protect against radiation from the sun and outer space.  And a higher atmospheric pressure means that we'd be able to walk outside on Mars's surface wearing only a breathing mask.  

So how can we give Mars a thick atmosphere?

Zubrin and McKay in a paper written in the early 90s did some estimates of how we could produce a much denser atmosphere on Mars by melting the southern ice cap.    They argued that if we raised Mars's average temperature by 4 degrees C, runaway global heating would occur, because rising temperatures would melt more of the ice cap's carbon dioxide which would in turn raise temperatures, melting more iced CO₂ and so on, until all the polar CO₂ ice was melted.  Then it would be the turn of CO₂ adsorbed into the regolith.  As temperatures rose, that would also be released into the atmosphere, ultimately raising the air pressure from CO₂ alone to between 500 - 1000 mbar.

However, this calculation is crucially dependent on how much CO₂ there is in the ice caps and the regolith, and 27 years after Zubrin and McKay wrote their article, new estimates suggest there is much less of it than was thought then.  In fact, instead of polar CO₂ raising the air pressure by 50 - 100 mbar, it might only raise them by 10-15 mbar.

As the chart below shows, that is not enough to raise temperatures by enough for the CO₂ not to be redeposited at the poles all over again.   The freezing point of CO₂ varies with the air pressure; the higher the air pressure, the higher the freezing point.  But at 200 mbar (1/5th Earth's air pressure—for comparison air pressure at the summit of Mt Everest is 337 mbar), the freezing point of CO₂, is around  -95 Celsius; at 300 mbar around -90 Celsius.

But, if we could get the temperatures up another way, for example by manufacturing sulphur hexafluoride, a greenhouse gas 23,000 times as potent as CO₂, then the CO₂ would remain in the atmosphere and not freeze out.  Unlike CFCs, also powerful man-made greenhouse gasses, which are chlorine compounds, sulphur hexafluoride won't destroy any nascent Martian ozone layer, needed to reduce the impact of ultra-violet rays from the sun.   By the way, humans would be able to go outside their domes without a pressure suit (but with an oxygen mask) at 200 mbar, though 250 or 300 would be preferable.

 

Data derived from Zubrin and McKay's formulae.

So do we have to give up hope of terraforming Mars?

No, not at all.  Because we can bring other volatiles (gasses, or substances which can be gasses or liquids, like water) from asteroids and Kuiper belt objects.  In an article in The Space Review, John Strickland suggested that the volatile of choice should be nitrogen, aiming initially for a 50/50 nitrogen oxygen mix and then, later, a 70/30 mix.  The nitrogen would be harvested by robots from nitrogen slush on Kuiper belt objects.

With current technology this is impossible, but (a) who knows what will be available in 20 years?, and (b) we are talking about colonising Mars, and we haven't even sent humans there yet. SpaceX will have gone from a Mariachi band and a carpet  to uncrewed Starships on Mars in 20 years.  My guess is that 20 years after we put the first humans on Mars, we will be exploring the asteroids and the Kuiper belt.  Using Strickland's calcs, I calculate that every 36 loads of 100 million tonnes each of nitrogen would raise air pressure by roughly 1 mbar.  If we wanted to raise pressures by 10 mb a year, we'd need 360 loads annually, and we'd reach 200 mb in 20 years, ignoring any desorption of CO₂ from the regolith.  A target of 3 mb air pressure increase a year would mean 120 loads, or 1.2 billion tonnes, annually.  A massive undertaking, but by then it will be technologically feasible. After all,  we transport 2 billion tonnes of oil across the globe each year, while all we have to do once we have mined the nitrogen is to give it a push.  In space, there is no air friction to slow vessels—once started, the load will keep going, though it will make it quicker if we can accelerate it.  Once we have fully re-usable spacecraft, space will become really, really cheap.  Shipping stuff from the asteroid or Kuiper belts to Mars and Earth will be easily affordable.

Without using lots of fuel, the journey by asteroids from the asteroid belt could take a decade, and from the Kuiper belt several decades.  So this kind of rapid terraforming won't start until we've been on Mars for 30+ years, assuming we take 20 years from the first colonisation to being able to mine the asteroid and Kuiper belts.  (Asteroid belt mining will likely happen long before we start crewed explorations of the Kuiper belt)

Another way to get volatiles like water and nitrogen is to bombard Mars with comets or asteroids.  We're talking hundreds of comets, all aimed with exquisite precision.   You don't want to hit a domed city, but even the shockwave from an impact with the surface would be very destructive. To prevent this, the comets will have to be disintegrated before they hit the atmosphere.  It will likely be doable by 2040.  We'll have the technology.  It's be costly, but as the population of Mars rises, the political will and financial ability to terraform Mars will also rise.  Because the asteroids and Kuiper belt objects are not in deep gravity wells, the fuel needed to nudge their orbits so they intersect with Mars's orbit, or to send nitrogen from them to Mars, is low.  Even Pluto (now a planet again, I see) only has an escape velocity of 0.62 m/sec² compared with Mars's 3.711 m/sec² and Earth's 9.807 m/sec².

But all these terraforming techniques will take many many decades to take full effect.  A century, prolly.  Or more.  For the first couple of hundred years we will be living on Mars in domes or underground.  And perhaps only when air pressure reaches 300 mbar will we be able to start greening the surface of Mars, and then only with genetically modified plants.  Although there is some evidence that lichens might grow in deep valleys or craters on Mars at current pressures, and oxygen-making cyanobacteria might survive when there is liquid water for much of the year at the equator.

A final point: Mars lost its atmosphere because it had no magnetic field to deflect the solar wind (a stream of charged particles from the sun, essentially the nuclei of hydrogen atoms).  To stop this happening again, we'd have to give Mars an artificial magnetosphere, perhaps by situating a giant magnetic dipole (electric magnet) at the L1 Lagrange point.  The authors of the NASA study estimate that because there is still outgassing of volatiles from Mars's interior, an artificial magnetosphere alone would be enough to eventually raise atmospheric pressure on Mars to allow for liquid water on the surface.  Other analysts disagree, saying that volcanic outgassing is no longer enough to build an atmosphere.  Either way, an artificial magnetosphere will stop Mars losing its new atmosphere like it lost its old one.  If there is outgassing, then that will be a bonsella.

Our society will be wealthy enough one day to terraform Mars using nitrogen and water from asteroid or Kuiper belt objects, with an artificial magnetosphere to protect it.  Just as the Dutch tax themselves to maintain the dikes which protect them, so will Martians pay for the terraforming of their planet.  It just won't be as easy as Zubrin and McKay hoped.  Not their fault: we have much better information about Mars now than we did 30 years ago.   But terraforming Mars will happen, and prolly much sooner than we think.

o—o—o—o—o

These are the other pieces I've written about living on Mars:

Living on Mars -- I

Living on Mars -- II

Living on Mars -- III

Imitation & vat meats the norm by 2040

Domed forest on Mars 

Terraforming Earth 

Cost of the Mars expedition 

Cheap access to space

These are some of the reference works I consulted:

Temperature of Mars
Carbon Dioxide and water phase diagrams
Terraforming Mars, Wikipedia
Could we terraform Mars? -- PBS Space Time
Nuking Mars's Icecaps won't geoengineer it
Rethinking the Mars terraforming debate (Strickland)
The biology of low atmospheric pressure
Technological requirements for terraforming Mars (Zubrin and McKay)
Inventory of CO2 available for terraforming Mars
NASA proposes building an artificial magnetic field to restore Mars's atmosphere

Our only home

A cartoon by the Melbourne cartoonist Judy Horacek.

(Some people think Mars will save us.  Nope.  Its average temperature is -60 C, its atmosphere is virtually non-existent, its soil (regolith) is toxic, it's bathed on dangerous radiation, and it will take decades/centuries plus billions to terraform it.)

Terraforming Earth

The Tadart Acacus desert in western Libya--part of the Sahara desert.
Source: Wikipedia

There's a lot of talk about terraforming Mars--raising its temperatures, thickening its atmosphere, reducing atmospheric CO2 from nearly 100% to a more breathable Earth-like 0.4%, and increasing oxygen to 20%.  There are formidable technological and economic hurdles in the way, starting with the fact that we haven't yet even landed a human on the surface of Mars.  But what about terraforming Earth?  For example, could we reverse desertification on the fringes of existing deserts?  Could we even make the deserts green, somehow?

This piece suggests one way--if we covered the Sahara with wind and solar farms, it could change the climate and increase rainfall.

It's the largest hot desert in the world: the Sahara, a blistering landscape of sand, heat, and deadly dryness that swallows 10 nations and is growing bigger all the time.

Because of its searing, sunny conditions, numerous energy projects are already seeking to capitalise on the immense solar potential of the Sahara.

But new research shows an amazing, unprecedented effect of these efforts: solar and wind farms could actually bring rainfall and greenery back to the desert.

"We found that the large-scale installation of solar and wind farms can bring more rainfall and promote vegetation growth in these regions," says one of the researchers, atmospheric scientist Eugenia Kalnay from the University of Maryland.

"The rainfall increase is a consequence of complex land-atmosphere interactions that occur because solar panels and wind turbines create rougher and darker land surfaces."

"Our model results show that large-scale solar and wind farms in the Sahara would more than double the precipitation in the Sahara, and the most substantial increase occurs in the Sahel, where the magnitude of rainfall increase is between ~200 and ~500 mm per year," says first author of the study Yan Li, who began the research at Maryland and is now at the University of Illinois at Urbana-Champaign.

"As a result, vegetation cover fraction increases by about 20 percent."

These effects arise for a couple of reasons. Firstly, wind turbines enhance vertical mixing of heat in the atmosphere, pushing higher, warmer air down to the surface and increasing land surface friction, and ultimately leading to greater likelihood of precipitation.

"This increase in precipitation, in turn, leads to an increase in vegetation cover, creating a positive feedback loop," Li explains.

At the same time, solar panels, which soak up the Sun's rays, reduce what's called surface albedo – the amount of light reflectance at the surface – which also ends up increasing precipitation.

It wouldn't be easy to build this kind of hypothetical infrastructure, of course – we're talking a solar farm roughly the size of China or the United States, punctuated by giant turbines covering about 20 percent of the Sahara.

But if we could pull such an epic feat off, we wouldn't just be kickstarting a gradual greening of the Sahara desert – we'd also completely kick our addiction to fossil fuels, with the complex delivering about 82 terawatts of electrical power annually, the team calculates.

"In 2017, the global energy demand was only 18 terawatts, so this is obviously much more energy than is currently needed worldwide," Li says.

[Read more here]

We're prolly not going to cover the Sahara with wind and solar farms just yet, if only because doing so would provide four times as much electricity as the whole world needs, and anyway, we are still reluctant to build wind and solar farms even when they are profitable.  But it seems very likely that we will need to have a period of negative emissions after 2050, where carbon dioxide is removed from the atmosphere.  And an easy way to do that is to plant a forest. 

It's tempting to think that the Sahara has been ever thus.  But it's not true.  There was a time when the Sahara was wet, and covered with savanna, forests and "huge Saharan lakes".   And although many scientists believe that this was caused by changes in the Earth's axis, some maintain that it was worsened by desertification as a result of the spread of pastoralism.

The Sahara today forms one of the largest and driest expanses of land on Earth. Yet between 5,000 and 10,000 years ago, a period of time commonly referred to as the ‘African Humid Period’, both the climate and ecosystem of the Sahara were dramatically different. Instead of an arid desert landscape, the Sahara was characterized by lush and diverse vegetation, a consequence of monsoons and increased rainfall over the northern Africa landmass.

The ending of this unusually wet period in the Sahara’s history, and transition to modern-day conditions, has long been a target for scientists trying to understand climate and ecological tipping points; until now, most studies have pointed to changes in the Earth’s orbit or natural changes in vegetation as the major driving forces. A new paper in Frontiers in Earth Science by archaeologist Dr. David Wright, from Seoul National University, South Korea, challenges this view and suggests that humans may have also played an active role in driving climate change in this period.

“During the African Humid Period the Sahara had a completely different vegetation regime” explains Wright. “All of the plants that are found in the Sahara today were there, but you also had plants that are found in the Sahel, the semi-arid zone to the south of the Sahara, and even types of plants that are found in the Congo rainforest”. This so-called ‘Green Sahara’ was also capable of supporting large animals – rock paintings made in northern Africa dated to this time period depict crocodiles, elephants and giraffes, animals that could not be sustained in the Sahara today.

The wet conditions also had an important influence on human sustainability and cultural development, allowing humans to thrive in foraging and fishing communities. “Unlike a lot of other places, people in the Sahara became very sedentary, there was really no need for agriculture”, says Wright. “One of the dietary staples of people living in that period was Nile perch, an enormous 150 kg fish, and this was only possible due to the huge Saharan lakes which could support abundant fish and fishing populations”.

But such favorable conditions didn’t last. Although the exact timing and spatial distribution is still under debate, there is consistent agreement in geological and archaeological records that beginning approximately 8,200 years ago, the Sahara began a trend towards more and more arid conditions. Over the course of the next 3500 years, the landscape of northern Africa shifted from a diverse, wet ecosystem to conditions similar to those found today.

The underlying causes of this drying and desertification has previously been attributed to subtle changes in the Earth’s orbit, which in turn influenced atmospheric weather patterns and led to a reduction of the amount of rainfall in northern Africa. But Wright, whose scientific research has led him to exploring Neolithic-age archaeological sites all over the world, suggests that this is not the full picture. “In East Asia there are long established theories of how Neolithic populations changed the landscape so profoundly that monsoons stopped penetrating so far inland”, explains Wright, also noting in his paper that evidence of human-driven ecological and climatic change has been documented in Europe, North America and New Zealand. Wright believed that similar scenarios could also apply to the Sahara.

[Read more here]

If you think that this sounds far-fetched, consider that forest clearing in the Amazon is reducing rainfall, exactly as Dr Wright  postulates happened 8000 years ago in the Amazon. I read somewhere once that a tropical rain forest actually evaporates/transpires more water into the air than the same area of tropical sea, but I couldn't find the reference.  However,  a large oak tree transpires 400 litres (110 gallons) of water every day, when it is in leaf.  This is similar to the rate at which warm seas evaporate water into the air.  So it seems plausible.

Now, deserts from in the mid latitudes are caused by Hadley cells.  Essentially, what happens is that hot air at the equator rises, flows polewards until it reaches roughly latitude 30, and then descends, heating and drying as it descends.  This produces the bands of deserts around the world between 20 and 30 degrees latitude.  However, the humidity and consequent atmospheric instability on the east coast of continents stops this effect.  Compare the climate of Savannah, Georgia (latitude 32 degrees N) on the east coast and the climate of LA (latitude 34 degrees N) on the west coast. This difference is caused by ocean currents: on west coasts the ocean currents flow from cool to warmer regions, on east coast from warm to cooler, producing atmospheric instability and humidity, which leads to rain, not just over the immediate coast but deeper into the adjacent landmass. 

The atmospheric instability over a rain forest is likely to be as great as over a warm ocean.  Thus if we could establish a rain forest over the Sahara artificially, it might conceivably be self-sustaining. 

Most of the water released by evapotranspiration to the atmosphere as water vapor will be returned to the forest as rain, so rainforests provide their own rainfall. Although forests account for only about 15%-20% of global water evaporation, approximately 65% of the rainfall over land is due to them. Lowered levels of atmospheric water vapor reduce cloud cover and rainfall, so if forest is removed, rainfall in that region will be substantially reduced. 

[Read more here]

The only area where this won't work is the western Sahara where cool ocean currents produce a surface air temperature inversion which makes rising thermals and therefore rain impossible, except for the trailing edge of sub-polar frontal cyclones.

We may need to afforest the Sahara (and Arabian) deserts to remove carbon from the atmosphere as well as reducing the world's temperatures (rainforests are much cooler than deserts), and we will be able to do it using cheap electricity from solar and wind to produce desalinated water and cheap pumping.  To me, this seems at least as desirable as terraforming Mars, and far cheaper.  And we may have to take desperate measures over the next few decades to prevent runaway global warming.