Buy, sell, lift-off: the global economy is going interplanetary

By Gordon Roesler

Harvesting space resources will raise living standards worldwide, without further damaging Earth. So how can those resources be tapped in a way that will produce a return on investment?

That question may have been hypothetical in the past; now, it’s of pressing concern.

In February, the centre I work for at UNSW hosted a forum on an exotic topic: mining the resources on asteroids and the moon. It brought together space engineers, world-class Australian miners, and some Australian experts in fields such as robotics.

The event followed announcements of some start-ups in off-Earth mining, some of which had powerful backers. It seemed like a typical, low-key academic exercise.

To our surprise, the forum received international media attention. We were exhausted by a week’s worth of constant TV and radio interviews. No-one expected this, and we’re still struggling to understand it.

Interest may have been fuelled by some of the novel space accomplishments of the last year:

• a commercial company, SpaceX, has built an unmanned spacecraft that has twice rendezvoused and attached to the International Space Station (ISS)

• NASA is testing robots at the ISS for refuelling satellites on orbit

• the Curiosity rover is drilling rocks on Mars: just as one might prospect for minerals on an asteroid

Curiosity’s first sample drilling. NASA/JPL-Caltech/MSSS

These high-profile missions are in the collective consciousness, and many people may know preliminary plans are underway for an asteroid-capture mission.

Such space feats also suggest that the technology is more in hand than one realised – more science-fact than science-fiction.

The challenge now is to establish viable businesses, and the economics must be clarified to bring investors to the table.

For what it’s worth

What are space resources even worth? Consider the asteroid, named 2012 DA14, that buzzed past the Earth in February. One valuation of its water and mineral contents was US$195 billion. Another was zero.

Well, that’s helpful.

Such ambiguity arises from the lack of market definition. One could bring resources back to Earth, where markets exist. There are valuable resources out there, such as the platinum and diamonds known to be on asteroids.

But terrestrial market prices probably do not support the costs of obtaining solar system minerals.

By contrast, resources obtained and used in space have an inherent value: the avoided cost of launching equivalent resources from Earth. Today that’s at least US$7 million a tonne to low Earth orbit, and perhaps three times that to higher orbits. That represents an attractive price for those resources.

But markets for in-space uses of space-obtained resources are currently hypothetical: filling fuel depots to make interplanetary travel more efficient; processing in-situ resources to support human settlements; building orbiting solar power stations to beam clean energy to Earth.

Large orbiting space solar power station. NASA/Kennedy Space Center/NextGen

Resources that will be valuable in space will not be the ones that could be sold back on Earth. As a colleague said at our forum: “If you’re stranded in the desert, gold is useless and water is priceless.”

The two most valuable commodities could be construction materials (for the structure, say, of a huge space solar power station) and water (processed into rocket fuel, or used for human habitation).

Emerging markets

How will space resources markets emerge? Some people have suggested they will come to the fore via a disruptive innovation model, whereby a lower-quality, lower-cost product makes small inroads into an existing market, the profits fund product improvement and, eventually, the new product dominates.

But since there is no existing space market, this would seem unlikely.

Perhaps the commercial aviation industry provides a better model. This market, so critical to the global economy, has grown for decades at 4% even in the US, and 5% worldwide. As we all know, that industry began modestly.

A Qantas ancestor. Gordon Roesler

Government investments, such as air-mail services and air traffic control systems, were critical to aviation’s early growth and ultimate profitability. New applications continuously expand the market – so we can thank commercial air-cargo services for fresh sushi.

The space resources market is likewise developing modestly. The first product the American “asteroid-mining” company Planetary Resources will launch consists of tiny, low-cost telescopes:

Planetary Resources’ first-generation space camera. Planetary Resources.

The telescopes’ primary function is to find asteroids suitable for mining, but they may also be used to image the Earth, generating near-term revenue while waiting for the resources market to develop.

The business plan of the privately-held American company Deep Space Industries envisions medium-term revenues from operators of commercial communications satellites, who will buy propellant to extend the satellites’ lifetimes.

We have reached the point where the question is no longer “is the commercialisation of space possible?” but rather: “what is the path to return on investment?”

Combined economic, environmental and social forces will propel the industry to a high level of importance in the coming decades.

Gordon Roesler works for the Australian Centre for Space Engineering Research.

This article was originally published at The Conversation. Read the original article.

Satellite of love: our on-off relationship with the moon

By Jonti Horner

Like all relationships, our association with the moon has had its ups and downs.

In this series we’ve talked about the nature of the satellite and how we think it was formed – in a giant collision that tore Earth asunder.

We’ve seen how the moon interacts with Earth, raising tides as it gradually recedes into space. And we’ve been through some of the ways that the moon may have helped to shape life on Earth.

But what about human interaction with the moon – past, present and future? That’s the topic of this final article on our nearest neighbour.

Moon exploration

Since we first looked at the sky, the moon has played a prominent role in our stories and mythology.

The first image of the far side of the moon as captured by the Luna 3 shuttle in 1959. NASA

It’s only natural that, once humans learnt how to escape Earth’s gravitational pull, the moon would be the first place we’d visit. Stories of trips to the moon date back at least 2,000 years.

The first successful mission to the moon was the Russian spacecraft, Luna 2, which crashed into the moon on September 14, 1959 – less than two years after the launch of Sputnik 1, Earth’s first artificial satellite.

Less than a month later, the Soviets launched Luna 3, which returned the first images of the far side of the moon, revealing that the two sides of our satellite look hugely different: something current theories of lunar formation are still striving to explain.

Of course, this being the Cold War, the Americans were not to be outdone, and in May 1961 John F. Kennedy committed the US to the space race, with the promise of:

Before this decade is out, landing a man on the moon and returning him safely to the Earth.

JFK’s “moon speech” to Congress in 1961.

The mid-1960s to mid-1970s marked a golden age in lunar exploration. The first probe to soft-land on the moon (the Russian Luna 9 in February 1966) was quickly followed by the first lunar orbiter (Luna 10, April 1966).

The first men to orbit the moon, the crew of Apollo 8 (Frank Borman, James Lovell and William Anders), entered lunar orbit on Christmas Eve, 1968, and set the stage for what remains one of mankind’s greatest achievements – on July 20 1969, man first walked on the moon.

The Apollo 11 mission, crewed by Neil Armstrong, Buzz Aldrin and Michael Collins (who remained on board the lunar orbiter while Armstrong and Aldrin got to walk on the surface) was a worldwide sensation.

Around the planet, people watched as, for a couple of hours, Armstrong and Aldrin explored the lunar surface, planting the US flag, gathering rocks and soil samples, and bounding around like kangaroos in the low gravity.

Giant leaps indeed.

Five more Apollo missions (Apollo 12, 14, 15, 16 and 17) carried men to the moon.

Apollo 13 almost went catastrophically wrong, and later became the subject of a Hollywood blockbuster, but after 1972, things stopped.

When Eugene Cernan stepped back into the lunar lander on December 14 1972, he said:

I’m on the surface; and, as I take man’s last step from the surface, back home for some time to come — but we believe not too long into the future — I’d like to just [say] what I believe history will record. That America’s challenge of today has forged man’s destiny of tomorrow. And, as we leave the moon at Taurus-Littrow, we leave as we came and, God willing, as we shall return: with peace and hope for all mankind. Godspeed the crew of Apollo 17.

I doubt anyone would have expected that, more than 40 years later, we would not have returned.

Modern and future moon exploration

In the past two decades, lunar exploration has begun anew, with Japan, the European Space Agency, China and India joining the US and Russia as nations to have explored our satellite – albeit with unmanned probes rather than human explorers.

These lunar orbiters continue to make exciting discoveries about our nearest neighbour – including the presence of water ice on the lunar surface. They have mapped the moon’s gravity, allowing the structure and composition of the moon to be studied in great depth. They have even obtained images showing the Apollo landing sites.

China’s space program continues to grow, with an unmanned lunar landing planned for later this year. EPA/Michael Reynolds

Much of the current exploration of the moon is focused on the idea it might be possible, one day, to return, and perhaps even mine there for precious resources such as Helium-3, which is incredibly rare on Earth, but thought to be much more common in the lunar regolith as a result of its continuous bombardment by the solar wind.

To that end, the Chinese lunar lander and rover mission Chang’e 3 is currently scheduled for launch late this year. If successful, it will be the first time we have successfully made a soft landing on the moon’s surface since Luna 24 in 1976.

Further in the future, it is almost certain that we will return to the moon – whether to mine the surface, or perhaps just as tourists.

After all, it would be a tragedy if Eugene Cernan’s excursion on the lunar surface back in 1972 was to remain our last steps on another world.

This is the fifth and final part of our series on the moon. To read the other instalments, follow the links below:

Part One: I see the moon: introducing our nearest neighbour
Part Two: Crash – a-ah! Our moon has a history of violence
Part Three: Out on the pull: why the moon always shows its face
Part Four: With or without you: the role of the moon on life

Jonti Horner does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

This article was originally published at The Conversation. Read the original article.

With or without you: the role of the moon on life

By Jonti Horner

From encouraging the first steps of life migrating from the oceans to the land, to stabilising Earth’s axial tilt against chaotic excursions, the moon is often put forth almost as a magical ingredient – a prerequisite for life.

Of course, the question of the origin of life on Earth has long puzzled scientists. To date, no one has come up with a totally convincing origin story – and there are even suggestions that life may have originated elsewhere, and been delivered to Earth on the comets and asteroids that bombard our planet.

This theory, panspermia, is attractive, since it removes the burden of life having had to form on our planet, giving us an infinitely greater range of origins, mechanisms, and times.

It is certainly the case that biologically-viable bacteria can be transferred between the planets.

Richard Dawkins talks panspermia.

Numerous studies (typically involving firing bacteria in small projectiles out of guns at speeds of several kilometres per second to crater a target) have shown that bacteria can survive the shocks involved in the collision between asteroids and planetary surfaces, while experiments on the International Space Station have shown how bacteria can survive and remain viable for long periods of time in space.

But for now, let’s just consider those theories that suggest life originated here, rather than being brought from elsewhere.

For theories that suggest life originated on Earth, it has often been proposed that the moon may have played in important role in its origin.

The youthful Earth was a vastly different place to the planet we observe today, but current thinking holds that our early oceans contained a plethora of organic molecules of varying complexity.

kevin dooley

Many mechanisms have been proposed for the origin of those molecules, ranging from delivery by cometary and asteroidal impactors to a huge variety of chemical processes, or even production through radioactive decay!

The question of how those molecules went on to become life is another thing entirely. Again, a number of different theories have been put forth, but one particularly relevant to our story relies on the presence of the moon driving vast tides, which created huge tidal areas, in which complex chemistry would occur.

We know that, shortly after its formation, the moon was very, very close to Earth, and that therefore the tides it would raise on the oceans would be far, far greater than those we see today.

Since the days were far shorter, tides washed in and out again with great frequency, creating vast tidal areas on the boundaries of any continents that existed at the time.

Tidal regions create high-energy environments. NASA

Some authors have suggested these tidal regions helped to concentrate radioactive materials near the high-tide line, which would in turn have helped to make the building blocks of life.

Others point out that the constant grinding of the tides would have created sands and small grained sediments, greatly increasing the surface area available to catalyse chemical reactions, again facilitating the development of life’s building blocks.

Although it is far from certain, it’s definitely feasible that the moon may have played a role in the origin of life. But what about its influence on life since?

The moon and Earth’s habitability

In their book Rare Earth: Why Complex Life Is Uncommon in the Universe, published in 2000, Peter Ward and Donald Brownlee argued that planets, such as Earth, hosting complex life are likely to be incredibly rare throughout the universe.

Among many other arguments, the moon played a central role in their “Rare Earth” hypothesis.

Ward and Brownlee argued that the presence of an over-sized moon, such as ours, is most likely a key component to making a planet habitable.

A moonglow image of the Earth and Moon. NASA

Part of their argument was based on the fact that, were the moon non-existent, the tides raised on Earth (solely due to the influence of the sun) would be smaller, and that this might have inhibited the development of life.

Beyond this, they argued a key component of Earth’s habitability has been its remarkably stable axial tilt by the presence of the moon.

Without the moon, they argue, the Earth’s axis would vary hugely, and chaotically, on timescales of millions of years – ranging from almost no tilt at all, through the planet’s current tilt (just over 23 degrees), to our planet being tipped over on its side, like Uranus, causing all locations on the planet to experience six months of daytime, followed by six months of night, every single year.

While such an idea sounds somewhat outlandish, it is based on observations of the planet Mars.

At the current epoch, the axial tilt of Mars is almost identical to that of Earth – 25 degrees against our 23 and a half.

However, while Earth’s axial tilt varies by only a degree or so in either direction, that of Mars is far more chaotic.

Our relatively stable axis is apparent in long exposure photos. Brandon Townley

In fact, it is thought that Mars’ axial tilt varies between 0 degrees and around 60 degrees, over a few million years, as a result of perturbations from the other planets.

Thus, this would render the planet hugely inhospitable for complex life.

This hypothesis (that the moon is required to stabilise Earth’s axis) has unfortunately not stood up to scientific scrutiny. A study by Dave Waltham, of Royal Holloway, University of London, revealed something far more interesting.

The Earth’s axial tilt is actually remarkably stable for a wide range of Earth-moon configurations (even for scenarios without the moon).

But, were the moon just slightly larger (by around ten kilometres, just a third of 1% of its diameter), it would force Earth’s axis to become unstable, driving a hugely chaotic motion.

More recently, other researchers have reached the same conclusion – a giant moon is not needed for Earth’s axial tilt to be stable.

In other words, had the “big splash” that formed the Earth-moon system created a satellite just slightly larger, Earth would likely be a far less pleasant place for life to develop and thrive.

And perhaps “Earths” aren’t quite as rare as we might otherwise have thought.

This is the fourth part of our series on the moon. To read the other instalments, follow the links below:

Part One: I see the moon: introducing our nearest neighbour
Part Two: Crash – a-ah! Our moon has a history of violence
Part Three: Out on the pull: why the moon always shows its face

Jonti Horner does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

This article was originally published at The Conversation. Read the original article.

Out on the pull: why the moon always shows its face

By Jonti Horner

Technically, Pink Floyd had it wrong. The space-facing side of the moon isn’t dark (except at full moon when Earth is between the sun and the moon). Not that you’d know that, given we always see the same side of our nearest neighbour.

To understand why the we only see that one side, we need to explore the relationship between the moon and Earth, and the forces that will slowly, but inexorably, sling the moon from our orbit into space.

As the moon orbits Earth, its gravitational pull raises “tidal bulges” on our planet. Both solid ground and oceans respond to this pull, causing the moon to raise land and ocean tides.

At the same time, the sun also raises tides on Earth which, while noticeably weaker than those caused by the moon, adds a level of complexity to the tides we experience.

When the moon and sun are aligned correctly (either at new moon – when the moon is approximately between Earth and the sun – or at full moon, when Earth is approximately between the moon and the sun), the tides induced by the moon and sun add together, and we get extra-high and extra-low tides. These are commonly known as “spring tides”.

Equally, when the moon and sun are pulling at right angles to one another, their influence cancels out, to some extent, and we get “neap tides” – high tides are at their lowest, and low tides their highest.

Slow spin-down – the long-term influence of tides

Beyond just causing the daily ingress and egress of the ocean onto land, tides raised by the moon on Earth have another interesting effect – they are slowly causing Earth’s rotation to slow.

Walraven

As we all know, Earth spins on its axis once a day, but the moon takes almost a whole month to orbit our planet. As a result, the location of the tidal bulges from the moon move around our planet significantly more slowly than Earth’s surface spins.

Friction causes the bulges to be pulled along with Earth’s motion, to some degree, and they end up slightly ahead of the location directly beneath the moon.

While friction with Earth tries to pull the bulges ahead of the moon, the moon’s gravity tries to keep the bulges aligned beneath it. The end result of this conflict is to cause Earth to slowly spin down, losing rotational energy to the drag from the tidal bulges.

That energy is transferred to the moon, causing it to speed up in its orbit, and therefore gradually swing away from Earth.

The moon’s gravitational pull is what causes tides of “high” – as seen here at Bondi Beach – and “low” tide. AAP/James Horan

We’re slowly growing apart – the moon’s recession

The rate at which the moon is receding from Earth is relatively small, but easily measured (using the retroreflectors left on the Moon’s surface by the Apollo astronauts, among other techniques).

The moon’s effect on tides, explained.

Currently, the recession is only around 22 millimetres a year, causing one Earth day to lengthen by about 23 microseconds a year.

While that doesn’t sound like much, it means the moon was once much closer to Earth, and Earth was spinning far faster than its current 24-hour rotation.

Again, these are both properties best explained by the “big splash” that created the Earth-moon system.

Synchronous rotation

Interestingly, that same tidal evolution is the reason the moon now keeps one face continually pointed towards Earth.

1:1 spin-orbit resonance, or synchronous rotation, of the moon.

Earth exerts tides on the moon, just as the moon exerts tides on Earth. Since Earth is comparatively massive, the tides it raises on the moon are much greater than those raised by the moon on Earth. And those tides long ago slowed the moon’s rotation so that it spins on its axis exactly once in the time it takes to orbit our planet once. This is called “1:1 spin-orbit resonance” or synchronous rotation.

As the moon recedes from Earth, its orbital period will increase, but the strength of Earth’s tides will ensure its spin slows, so it will always continue to show the same face to our planet.

This is the third part of our series on the moon. To read the first and second instalments, follow the links below:

Part One: I see the moon: introducing our nearest neighbour
Part Two: Crash – a-ah! Our moon has a history of violence

Jonti Horner does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

This article was originally published at The Conversation. Read the original article.

Crash – a-ah! Our moon has a history of violence

By Jonti Horner

The more we learn about the formation and evolution of our solar system, the more we realise it was far from a sedate, gentle process. Everywhere we look we find evidence the final stages of planetary formation were punctuated by giant collisions – planet-sized bodies ploughing into one another with predictably catastrophic consequences.

The planet Mercury, unusually over-dense and under-sized; the Martian “hemispherical dichotomy” (the marked difference between Mars’ northern lowlands and southern highlands); and Uranus’ extreme axial tilt are just three examples of odd features in our solar system best explained by such catastrophic collisions.

Part of the surface of Mercury that had never been imaged in detail before as photographed by the spacecraft Messenger in 2008. NASA

Planetary satellites in the solar system are thought to have formed in one of two ways. The “regular” satellites (those that orbit their host on circular paths, in the plane of their equators) are thought to have formed orbiting their planets, much as the planets are thought to have formed orbiting the sun – from a disk of material around their youthful host.

This does a very good job of explaining their low masses (relative to their host) and the way their orbits are aligned with their host’s equators.

The “irregular” satellites – a large population of typically tiny satellites, orbiting at vast distances from their hosts, on highly eccentric and tilted orbits – by contrast, are thought to have been captured during the latter stages of their host planets’ formation.

A map of the orbits of the irregular satellites of Saturn. The Singing Badger

Neither of these models works for our moon. Instead, the current leading theory for the moon’s origin is that it formed in a “big smash” – a collision between the proto-Earth and a Mars-sized body, a few tens of millions of years after the start of planetary formation.

The most widely accepted version of this theory holds that a Mars-sized object formed in the inner solar system, on an orbit very similar to that of the Earth. Eventually, the two bodies collided at a relatively low velocity (in astronomical terms).

The collision greatly disrupted the proto-Earth, but fell short of destroying it completely. Instead, vast quantities of material, primarily from the mantle and crust, were sloughed off into space around Earth, with a significant fraction of that material going on to form the moon.

The evolution of the moon in all its violent glory.

The beauty of this theory is that it explains some of the otherwise challenging things we know about the Earth-moon system. The moon is chemically and isotopically very similar to the Earth – but it is depleted in heavy elements such as iron.

That’s really hard to explain if you think the moon formed alone, then was captured in our orbit (since it would then have accreted similar amounts of iron to Earth). But if you accept the moon is made primarily from material from the mantle and crust of the Earth, then its composition makes perfect sense – after all, the Earth is differentiated, so most of the heavy stuff has sunk to the core.

This theory also explains the unusually high mass of the moon relative to the Earth (and the associated high angular momentum of the system), the moon’s unusual orbit, and many other features.

A number of slightly different versions of this story have been proposed in recent years – suggesting the collision could have been a bit faster, and even that the moon itself was involved in a second collision later on.

But the core of the theory is now widely accepted: the moon was (most likely) formed in a big smash.

This is the second part of our series on the moon. To read the first instalment, follow the link below:

Part One: I see the moon: introducing our nearest neighbour

Jonti Horner does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

This article was originally published at The Conversation. Read the original article.

I see the moon: introducing our nearest neighbour

By Jonti Horner

The moon. Our nearest neighbour. The main source of the ocean’s tides, and a beacon that drives the lives of animals across the globe. And also, to date, the only object beyond Earth on which humans have set foot.

Over the years, the moon has played a central role in the burgeoning understanding of our place in the universe. Yet despite its proximity to Earth, and the detail with which it has been studied, many of the moon’s secrets still elude us.

Neil Armstrong’s “small step for man” onto the moon was a defining moment of the 20th century. EPA/NASA

In this, and another four articles, I’ll introduce you to some of the ways in which the moon has influenced life on Earth, how it has taught us about the formation of the solar system, and the past (and future) of our exploration of the solar system’s strangest satellite. But first, some initial thoughts on our weird neighbour.

The moon: the stats

The moon orbits Earth at a mean distance of just over 384,000km. Its orbit is inclined to the plane of Earth’s orbit around the sun by just over five degrees.

If we were looking at the Earth-moon system from beyond Earth’s orbit, we would see the moon spends roughly half its time below the plane of Earth’s orbit around the sun, and the other half above that plane.

The location in its orbit at which the moon passes from below the plane of Earth’s orbit to above that plane is known as the “ascending node”. Over a period of around 18-and-a-half years, the location of the ascending node precesses around the moon’s orbit completely.

The Earth-moon dynamic, explained. infringer1

Because the rotation axis of Earth is tilted with respect to the plane of its orbit by 23-and-a-half degrees (the cause of the seasons), the moon’s orbital tilt, with respect to the Earth’s equator, varies over this 18-and-a-half year period between about 18 and 29 degrees.

The moon’s orbit around Earth is also slightly eccentric – at perigee (its closest distance to Earth), it’s a little over 362,500km from Earth, while at apogee (furthest from Earth), it is almost 405,500km away.

That might not sound like much – around a 10% variation in distance – but it means that the apparent size of the moon in the sky can vary quite markedly, as can be seen below.

The moon at its most extreme states of distance from Earth. Anthony Ayiomamitis/NASA

The moon is 1,737km in mean radius (compared to the Earth’s 6,371km), making it the fifth largest satellite in the solar system. But even though it is ¼ the diameter of Earth, it is significantly less dense than our planet (at roughly 1/81 the mass of Earth).

Even stranger is the fact that the near- and far-sides of the moon look so different. The near-side, familiar to anyone who has spent any time looking at the night sky, is dominated by the “mare”, basalt outpourings that span a large fraction of surface.

The far side of the moon, by contrast, looks totally different – a dichotomy that has long puzzled researchers (although a recent study may have come up with an explanation).

The strangest planetary satellite?

In the four centuries that have passed since the discovery of the Galilean satellites (the four moons of Jupiter), the number of satellites known through our solar system has grown to more than 170 moons. And it’s not just the planets that have been found to host companions: the solar system’s smaller bodies are also regularly accompanied by their own satellites.

The dwarf planet Pluto is now known to have at least five satellites, and companions abound in every population of solar system object we study.

The size of Earth’s moon as compared to other moons in the solar system. NASA

While there are several satellites larger than our moon (Jupiter’s Ganymede, Callisto and Io; and Saturn’s Titan), those satellites are all dwarfed by their host planet. In stark contrast, when compared with Earth, the moon is huge.

The other large satellites in the solar system orbit their host planets almost perfectly in the plane of their equator. Yet our moon’s orbit is inclined by between 18 degrees and 28 degrees to our equator.

So why is our moon so unusual? Why is it so different to so many of the other satellites in the solar system? The answer lies in the moon’s origin – and that’s a story we’ll return to shortly.

Jonti Horner does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

This article was originally published at The Conversation. Read the original article.

Moon mining a step closer with new lunar soil simulant

By Sunanda Creagh, The Conversation

Australian researchers have developed a substance that looks and behaves like soil from the moon’s surface and can be mixed with polymers to create ‘lunar concrete’, a finding that may help advance plans to construct safe landing pads and mines on the moon.

Valuable rare earth minerals, hydrogen, oxygen, platinum and the non-radioactive nuclear fusion fuel Helium-3 (He-3) are abundant on the moon. NASA and other space agencies have shown interest in lunar mining but the US is yet to ratify a 1984 treaty that would strictly regulate moon resource extraction.

However, even if moon mining was allowed, lunar conditions are so different to Earthly conditions that new machinery may have to be invented to develop resources found there.

Furthermore, the cost of transporting materials made on Earth would be prohibitive, forcing scientists to come up with ways to build certain equipment using material only found on the moon’s surface.

A research team led by Dr Leonhard Bernold, Associate Professor of Civil Engineering at the University of New South Wales, has created a new lunar soil simulant that closely resembles samples brought back by the Apollo astronauts.

Dr Bernold said such a simulant is essential to test lunar mining systems on Earth and may help researchers develop ways to create a waterless concrete using lunar dust, a component of the moon surface material known as regolith.

“We now know a lot about the mechanical properties of the regolith on the moon so we can create something that simulates it. We have tried to match it as close as we can,” said Dr Bernold.

Dr Bernold’s lunar soil simulant is made up primarily of very fine basalt particles taken from a quarry in Kulnura on the NSW Central Coast.

“These particles are a byproduct of crushing the basalt to serve aggregates for making concrete or asphalt, but are too tiny to be useful and have to be thrown away,” said Dr Bernold.

“On the moon, those small particles are abundant, having being created by small meteorites hitting the lunar surface at high speed over millions of years, thus breaking larger stones down into tiny particles.

As well as providing a substance on which Earthly mining techniques can be tested, the simulant soil can also be mixed with polymers to create a lunar concrete, said Dr Bernold.

“So, for example, we can find ways to create an in-situ resource utilisation material to build a landing pad for rockets on the moon. When rockets are landing, they blow away fine soil and it’s like a sandblaster blasting everything around,” he said, adding that a proper landing pad on the moon would reduce the dangerous sandblaster effect.

“Everything we ship from Earth will cost a lot of money, so we want to do as much as we can from the material that’s available there on the moon in abundance.”

Dr Bernold, who said NASA had shown interest in his findings, is presenting his simulant this week at the Off Earth Mining Forum hosted by UNSW.

Professor Andrew Dempster, Director of the Australian Centre for Space Engineering Research (ACSER) at the University of New South Wales said a lunar soil simulant would help researchers better understand the properties of moon dust.

“The main value in this work is to do with the soils on the moon being so different to the type of soil on the earth and the type of soil most mining machinery is dealing with,” he said.

International treaties and special space laws would be needed to work out who had ownership rights to material mined from the moon, said Dr Dempster.

“I understand there’s an environmental argument around it too but if you were to mine the moon or an asteroid or other planets, there’s not going to be the environmental impact that local mining would have on the local biosphere. It’s a way of mining such that the mining process itself doesn’t produce any negative environmental impact,” he said.

“Obviously, however, you need to produce a lot of energy to go and do it.”

Students working with Dr Bernold are studying methods for harvesting and storing solar heat energy on the moon in a ‘lunar battery’ using materials found on the moon.

This article was originally published at The Conversation. Read the original article.