We're analysing asteroids in this edition of the Naked Scientists, as Earth is due a very near miss next week! We'll also meet the asteroid miners - companies looking to go prospecting in outer space - to find out how to mine an asteroid. Plus, the new material that can generate electricity from the heat in your hand, and what will the Large Hadron Collider be looking for next...
In this episode
01:35 - Electricity at your (hot) fingertips
Electricity at your (hot) fingertips
A group of Korean researchers have produced flexible films of thermoelectric material that can generate electricity with nothing more than the heat produced by a fingertip.
Thermoelectric materials can harvest heat and convert it into useable electricity, by acting as heat engines.
They depend upon a temperature difference to "drive" the conversion from heat to electricity - so one side needs to be hot and the other side cold.
This temperature difference makes the electrons on the "hot" side vibrate more vigorously so they tend to move towards the colder side where the electrons are moving more slowly. This movement gives rise to a current that can be tapped off as electricity.
Thermoelectric devices are already widely used, but most commercial devices are made from solid-state semiconducting materials, which are expensive to produce, often toxic and they need a large temperature difference to operate.
So, recent efforts to develop flexible, non-toxic organic thermoelectric polymers is gaining interest - these materials are cheap and easy to produce and, with some clever chemistry, can harvest electricity from very small temperature differences.
But there are challenges. The ability of a thermoelectric material to convert heat into electricity is defined by its power factor, a number related to its electrical conductivity.
The best thermoelectrics have high electrical conductivity, meaning that they allow electrons in the material to flow freely.
Generally, the materials used for organic thermoelectrics - conductive polymers - have low electrical conductivities, and this limits the thermoelectric power factor.
Now, Eunkyoung Kim and his team at Yonsei University in South Korea have developed a new thermoelectric material based on a material called PEDOT - poly(3,4-ethylenedioxythiophene) - which, they claim, shows a power factor of 1270 µW/mK2 - four times higher than any other conductive polymer published in the literature.
This means that it can harvest the tiniest amount of heat - even that produced by placing a fingertip on top of the material.
The PEDOT polymer was produced using standard large area film processing techniques. Kim and his team also used electrochemistry to control oxidation inside the film, and so optimised its electrical properties to produce this record breaking thermoelectric power factor. The material also has the added benefit of being very flexible - unlike many commercial thermoelectric materials.
By printing gold electrodes directly onto the PEDOT film, the team measured the voltage produced as one side of the film was cooled while the other was touched by a fingertip.
The PEDOT film produced 590 µV of electricity under a temperature difference of approximately 5 °C.
This may be five times smaller than the voltage produced by traditional, solid-state thermoelectric materials, but PEDOT films can be produced at a tiny fraction of the cost and many times more rapidly than these materials, so there are obvious gains to this technology.
It's fair to say that, with these miniscule amounts of electricity, we're unlikely to be wearing gloves that will charge up a phone or an iPod any time soon. But, the potential applications of these films are numerous. Many of today's sensors and microelectronic devices need only a few microvolts of electricity to operate, and these cheap, flexible, non-toxic films can produce that with only a tiny temperature gradient.
For thermoelectrics, it seems, the future may indeed be flexible.
04:59 - What's Next for the LHC?
What's Next for the LHC?
Still glowing from one of the scientific discoveries of the decade - the Higgs boson - the Large Hadron Collider at CERN, Europe's particle physics facility in Switzerland, is about to shut down for two years while it undergoes a refit.
Once it is back online it will collide protons at twice the energy as before, allowing it to probe the properties of the Higgs - the particle associated with the mass-giving Higgs field. It may also start to see hints of exotic new physics, such as supersymmetry, which some theorists hope could smooth out discrepancies between their theories of gravity and quantum physics.
Meanwhile, particle physicists are already planning a 'Higgs factory' called the International Linear Accelerator, which could be based in Japan and would produce far more of the prized particles.
Back at CERN, they're also getting ready to mount a fresh hunt - this time, for the sterile neutrino, a possible candidate for the Universe's missing 'dark matter'.
10:24 - Beauty and the Brain
Beauty and the Brain
Semir Zeki, a neuroscientist who is fascinated by the cognitive basis of beauty, pleasure and love, has measured the different ways our brains respond when we're making an aesthetic judgement compared to a perceptual judgement. So, in this case, he looked at how people's brains responded when they looked at two paintings and decided which was more beautiful compared to looking at two paintings and deciding which was more brightly coloured.
His main conclusion was that the two types of judgement are different- that making a judgement about aesthetics activated brain areas and neural pathways that were effectively silent when people decided how bright a painting was.
Two particularly important areas of our cortex (which is made up of the layers and layers of neurons that allow us to make memories and have higher thinking functions like attention and planning) that are activated when we're making a judgement about beauty is the orbitofrontal cortex, which doesn't seem to be activated at all when we're judging brightness.
Watching, measuring and understanding how these function will help to develop an idea of what exactly is going wrong in our brains when we have an affective disorder, such as depression, something that can rob people of their ability to appreciate beauty and take pleasure in things like music and art.
14:05 - Electrical stimulation stops migraines
Electrical stimulation stops migraines
"Migraineurs" experiencing regular disabling headaches might find relief in a daily dose of electricity.
Belgian neurologist Jean Schoenen from Liege University and his colleagues randomly allocated 67 migraine sufferers to receive, over a 90 period, either 20 minutes per day of self-applied electrical stimulation delivered using a pad applied to the forehead, or a "sham" (placebo) treatment using similar equipment.
The subjects, who did not know whether they were receiving the active or sham treatments, were asked to keep diaries of their migraine attacks during the treatment period.
Before the trial started, the participants had also logged their headache episodes for 30 days to establish a baseline for comparison.
Dubbed PREMICE (prevention of migraine using the STS Cefaly), the study showed a 30% drop in migraine days amongst the volunteers given the real treatment. This was reflected in a drop of 37% in the use of anti-migraine drugs amongst the treated participants but not amongst the control (sham) group whose analgesic consumption remained about the same.
Writing in Neurology, the team admit that the mechanism by which their intervention blocks migraine attacks isn't clear. The device delivers a small 16 mA current, stimulating to the supratrochlear and supraorbital sensory nerves, which supply the forehead region.
The resulting activity induced in these nerves could, the team speculate, be transmitted to central neural networks concerned with pain or migraine responses, altering the migraine threshold.
Previously, scientists have shown that magnetic stimulation can be used to block migraine attacks once they begin, most likely by damping down the waves of abnormal brain activity that appear to trigger the condition.
But this is the first time that a simple, readily-available piece of kit, not dissimilar to the TENS machines used to give pain relief to other parts of the body including during child-birth, has been shown to be effective.
16:30 - The Demise of the Dinosaurs
The Demise of the Dinosaurs
A team led by Paul Renne at the Berkeley Geochronology Center in California have shed new light on the asteroid impact that is believed to have wiped out the dinosaurs, 66 million years ago. Writing in the journal Nature this week, the team use a new technique to date both the extinction event and the nearly coeval asteroid impact, to better understand the sequence of events around what is known as the Cretaceous-Paleogene Boundary.
The extinction event at the Cretaceous-Paleogene Boundary was the most dramatic change to life on Earth, at least in the past 200 million years. It is estimated that at least 75% of species became extinct within a period of around a million years, including all species of flightless dinosaurs.
The puzzle in recent decades has been to work out what global change could have triggered such a catastrophe for the dinosaurs, which up until this point had thrived for tens of millions of years.
The evidence implicating a large asteroid impact is strong: rock deposits dating from the period are rich in iridium, a metal which is normally very rare on the surface of the Earth, but much more common in asteroids.
If an asteroid measuring around 10 km across collided with the Earth, throwing a large amount of debris into the atmosphere, this would explain the sudden abundance of iridium. It would also been very bad news for the dinosaurs, as the atmospheric debris would have obscured the Sun's light for a period of years, triggering the Earth to become a much colder place. It would also explain why plant life - unable to photosynthesise without much light from the Sun - was also particularly badly affected.
A large crater has even been identified near Chicxulub in Mexico which has almost exactly the right age.
But more recent studies have questioned whether this crater and the iridium deposits are really coeval with the extinction of the dinosaurs, or whether they actually date from 200,000 years later. Putting together the exact sequence of events has proven extremely challenging because of the length of time that has elapsed since.
Paul Renne's team made use of a new dating technique, using the very slow radioactive decay of some potassium atoms to form argon over periods of tens of millions of years. By looking at how much argon has accumulated in any given rock, they can arrive at the most precise ages ever derived for them.
Looking at rock layers associated both with the extinction at the Cretaceous-Paleogene Boundary, and also with the asteroid impact, the team have arrived at the most precise sequencing of events ever obtained. They conclude that the extinction event was already underway before the Chicxulub asteroid impact - probably because of changes to the Earth's climate - but also that the asteroid impact occurred while it was still underway. They conclude that dinosaur populations were already struggling to survive before the asteroid struck, but that the additional cooling triggered in the aftermath of the asteroid impact is likely to have provided the fatal blow.
20:21 - LiFi: Using light to send information
LiFi: Using light to send information
with Jane Reck, EPSRC, Professor Harald Haas, University of Edinburgh, Professor Martin Dawson, University of Strathclyde
Chris - You've probably heard of wireless communications or Wi-Fi. They use radio waves and microwaves to send information. A spinoff of that Wi-Fi is a Li-Fi. This is a system that uses visible light to send information into mobile devices and computers. But now, a consortium of UK universities is working on a way to take Li-Fi to a whole new level. The EPSRC's Jane Reck has been talking to the scientists behind this project.
Harald - Imagine that where we have light sources - street lamps, traffic lights, shopping windows. Light is everywhere and let's imagine a scenario that all these light bulbs are sort of high speed wireless transmitters that connect either humans with humans or systems with systems.
Harald - This whole area of Li-Fi, of using visible light for communications is based on the very recent emergence of light emitting diode technology as the source of lighting.
Jane - Tiny LEDs are being developed that could simultaneously do many tasks such as deliver internet connections, display information, and provide lighting. It's the next stage in research to use visible light to transmit information. Professor Harald Haas from the University of Edinburgh is one of the partners in project.
Harald - Li-Fi stands basically for light fidelity and what it essentially means is that we take the new generation of energy saving light bulbs which are made of light emitting diodes (LEDs) and we use them for illumination and data transmission. And not only data transmission, but very high data transmission. So, we envisage that these light bulbs will - in the future - achieve one gigabit per second and that is several times faster than a typical Wi-Fi system in a home can provide.
Jane - The tiny LEDs being developed are made from gallium nitride. A man-made semi-conductor material whose properties are ideal for high power, high frequency use.
Herald - The name, it's called ultra-parallel. It means we have a parallel transmission and the idea is sort of take many small devices where each small device is capable of transmitting very high amount data, much, much higher than a single LED, a large LED can do, take these sort of high performance little LEDs and put them into large areas so that parallel transmission is on-going.
Jane - Professor Martin Dawson from the University of Strathclyde is leading the project. He explains more about the novel aspects of this research and how Li-Fi will complement our existing communication systems.
Martin - One of the benefits that Li-Fi gives is it's bringing in a new region of the spectrum. So, it's adding spectrum to the available bandwidth for communications. Wi-Fi is clearly very, very successful technology, but there's been a raised concern about possible health issues. I should emphasise, there's been no evidence of any negative effect from this, but it remains a concern. If you're communicating with lights, with visible light then there is no concern about that. This is one of the aspects.
There's also the security aspects. It is possible to tap into microwave and radio broadcasts in a way that you cannot with visible light. It can also be deployed in situations where it's not safe to have microwave or radio waves present, and that could be in an operating theatre for example. It could be in a submarine or in an aircraft. So, if you look at the light emitting diode that might be on your Christmas tree or in a torch for example, if you looked at that under a microscope, you would see that the size of the chip in there is about a millimetre square. It's a sizable component. What we're talking about is basically dividing up that active area into many thousands of much smaller elements. These individual elements that we call micro LEDs or micro heads are human hair size individually. They're on the micron, micrometre scale and when you shrink down the size of the devices; there are effects that come in to play that offer you the possibility of switching them on and off much more quickly. And it increases the bandwidth with the on and off switching capability and speed, but some other beneficial characteristics start to come into play as well. When you do that, you give the possibility of sending independent communications from each individual element in the array. You not only have many, many hundreds or potentially thousands of separate individual lighting or communications channels that you can start to play with independently, but you also have a means to communicate optical images at the same time. This is the key element of novelty here.
Jane - With each tiny LED, acting as a separate communication channel, Martin explains more about the sort of tasks that could be carried out simultaneously.
Martin - If you are sitting at an aircraft with a light above you, if you're in a meeting room with lights above the meeting table, then those lights are a means of broadcasting and communicating information, a potential supplement or replacement to Wi-Fi, and we're expecting this to come in relatively quickly. There've been a number of demonstrations of this already all over the world. Our devices offer a potential means to increase the data handling capability in that type of application. We still have the capability to do lighting, but a means to communicate much higher quantities of information, so to download video information very quickly for example.
Jane - This consortium of researchers also involves the Universities of Cambridge, Oxford and St. Andrews with funding from the Engineering and Physical Sciences Research Council. The project brings together expertise from areas of electronics, computing, and materials. It's thought that Li-Fi could be in wide spread use within a decade.
27:36 - Avian Pox hits Great Tits - Planet Earth
Avian Pox hits Great Tits - Planet Earth
with Shelley Lachlish & Ross Crates, Oxford University
Avian pox affects a number of bird species, but it was discovered in UK's population of great tits in 2006. As avian pox is spreading, scientists are monitoring birds using trapping and ringing in order to study the disease. Sue Nelson visited the Wytham field station in Oxfordshire where she met the Field Manager Ross Crates and Oxford University's Dr. Shelly Lachish...
Shelly - It's actually a very distinctive disease. The birds develop large tumour-like lesions and they develop them on the head, particularly around the beak and the eye area, but also on their legs and on their wings. Basically, when we catch the birds and we have them in the hand, if they have a lesion, it's very hard for us to miss it.
Sue - Walking down the extremely muddy path...
Ross - We've actually got the mist net set behind the feeder. As we're walking down through it from here, we can't see it, but we can certainly see that we've caught a few birds in it. It looks like there's about 7 or 8 at the moment.
Shelly - It looks like we've got a nuthatch as well, just behind the cage there.
Sue - Right. So, you've got several great tits.
Shelly - Lots of blue tits.
Sue - Lots of blue tits, I recognise them.
Shelly - Most of these we've been looking at here are blue tits then there's a nuthatch there, and a coal tit.
Sue - Aren't they gorgeous?
Shelly - This is a good example of a re-trap here, so you can see its metal ring on one leg, and its passive integrated transponder on the other leg, just a little plastic ring here.
Sue - Oh yes, it's got little tiny rings on each leg.
Shelly - So what we do is we have antenna on our feeders and on the nest boxes, and when the birds come to feed or come to their nest boxes, we can record them without having to be there at all.
Sue - We've got two little white bags now with the birds in and you're putting all the birds in little bags...
Shelly - Yes. So here's another one that's already - we've already caught this one previously, so he has a little black pit tag on his right leg and a metal silver band on his other leg. So, we can look up the number on that ring and we can find out all the history about this bird - where he was caught last time, how much he's grown and whether he's breeding the last time he or she was caught, and we'd tally that information up and that feeds into our records. And he's still pecking me...
An avian pox is actually - we have noticed it in all of these species except for the nuthatches, but it's by far, more prevalent in great tits than any of the other birds. We're not actually sure why that is and that's one of the things that we would like to find out.
Sue - Well, I will let you continue extracting the birds and bagging them before we head back to the table.
Shelly - So now, we have our birds in their little bags, hanging here, waiting their turn to be processed. And so, one by one, we'll go through, we extract them from the bags like I have done with this little blue tit and I have it in my hands now. And now, begins the process of ringing and pit tagging, and measuring. And so, the first thing you'll always do is put on a ring because that's the identifier for the bird.
Sue - You just affixed that one very deftly.
Shelly - I have.
Sue - So, will you check in the future now to see whether when you catch a bird that has been previously tagged and ringed, whether it has the virus or not? All those birds that we trap looked quite healthy to me here.
Shelly - At this time of year, we do expect avian pox prevalence to be very low because it is a vector disease. It's mosquito vectored and winter is not a very good time for mosquitoes to be around.
Sue - Do they all die or do some survive?
Shelly - We've had 105 cases of avian pox in great tits, at least in this wood, and some extras in some blue tits and other species. And we've seen 14 of those had been recaptured again, and they've been asymptomatic so they haven't had lesion whereas they did previously. And so, we do know that recovery is possible, but our analyses are also telling us that this disease definitely kills the birds. It reduces the survival rate of individuals.
Sue - What have you discovered so far in terms of how far this viruses is spreading while you measure its wing - the blue tits wing there?
Shelly - The disease arrived in England in the southeast of England around the east Sussex area and that was in 2006. Since that time, we've seen it spread westwards right into Wales and as far north now as around the Mersey River around Manchester region. So, it has really spread quite a fair distance in just a number of years.
Sue - Is there anything that can be done at the moment other than monitoring it and studying it?
Shelly - That's our key focus at the moment, to track its spread, to know exactly what we're dealing with in the sense that whether we are dealing with something that will eventually be population wide amongst the great tits. But we are also continuing to look at genetic studies to try and isolate, further understand where the disease originated from and how it's mutated and suddenly appeared in this great tit population.
32:48 - Asteroids and Near Earth Objects
Asteroids and Near Earth Objects
with Dr Simon Green, Open University
On the 14th-15th of February 2013, Earth will have a truly close encounter. Asteroid 2012 DA14, a lump of rock weighing somewhere around 130,000 tonnes will pass just 24,000 km from Earth. That's closer than many satellites. Objects like these are known as Near-Earth Objects and they're of interest to scientists, but also to a group of entrepreneurs who are aiming to mine asteroids for their minerals.
Dominic - We're joined by Near Earth Object Specialist Dr. Simon Green from the Open University. First of all Simon, what do we mean when we talk about asteroids?
Simon - Asteroids are lumps of rock which formed in the inner Solar System, but never developed into a planet. So, they're essentially the building blocks of terrestrial planets like the Earth.
Dominic - And some of these are classified as near-Earth objects. Is there a strict definition of what that means?
Simon - Yes, anything that comes within 1.3 astronomical units. So, 1.3 times the distance of the Earth from the Sun is counted as a near-Earth object. Most likely, an asteroid, but it also could potentially be a comet.
Dominic - Roughly, how many objects are we talking about?
2004 FH is the centre dot being followed by the sequence; the object that flashes by near the end is an artificial satellite.
Images obtained by Stefano Sposetti, Switzerland on March 18, 2004. Animation made Raoul Behrend, Geneva Observatory, Switzerland. (c) NASA' alt='Timelapse of Asteroid 2004 FH's flyby (NASA/JPL Public Domain)' >
Simon - How long is a piece of string? It depends on the size. We know of about 10,000 objects at the moment, but that's just a tiny fraction of the total population. The smaller you go, the more there are, and so, there are many millions down to sizes of meters.
Dominic - I guess the big ones are quite easy to see, but the smaller ones are much harder to pick out.
Simon - That's right. The larger ones attract - we probably of 90 to 95% of all objects bigger than about a kilometre in size. Of things bigger than maybe 100 meters or so, we certainly know less than 10% of them.
Dominic - So, how do we go about looking for them?
Simon - With telescopes, we see it the best way using a wide field, CCD cameras and tracking the sky and looking for objects that move. So essentially, you'll look for objects that produce trails and images, or look like stars, but are changing position from minute to minute. And from the change in position, you can calculate the orbit.
Dominic - So, if you've got a near-Earth object that might come into collision with the Earth, how do you go about knowing how it's going to travel through the Solar System in the future?
Simon - The orbits themselves, you can calculate and predict where an object will go if it doesn't have any other forces and gravity acting on it, but you need enough observations in order to track its orbit as it is now, and then you do calculations based on the perturbations from other planets, other asteroids. And the predictions are fine until you have a close encounter with a large body, and then it's very, very difficult to predict afterwards. So, we can predict for objects when they might come close to a planet, but after that, we probably don't know. Now, most near-Earth asteroids, because they're in the inner Solar System, perhaps close to planets at some point, their orbits are not stable over long time periods. So, they probably only exist in the inner Solar System between 1 and 10 million years.
Dominic - Now, the object 2012 DA14 which is coming close to the Earth next week weighs 130,000 tonnes. How dangerous is an object that large?
Simon - This is actually the very bottom end of the kinds of objects that can penetrate the atmosphere and reach the ground. It's around 45 meters if you do the calculation, and it's possible if it's very fragile that it would explode in the upper atmosphere, much like an object in 1908 that damaged a large area of Siberia - fortunately, there were no people involved. If it's solid iron which might have come from the core of a larger asteroid, then it would certainly reach the ground and make a crater maybe 100 meters or larger in size. But this is at the very bottom end of the sort of damage scale, if you like, that we need to be worried about.
Dominic - We heard earlier about the asteroid that might have wiped out the dinosaurs. If we were to find an object that was quite large coming towards us, what could we do about it?
Simon - Something that big would be quite tough, but we'll probably know that that's not going to be the case, but something maybe a few hundred meters in size up to a kilometre, we would need to be able to try and deflect it. And then we need to therefore know its orbit and predict where it's going to go with many years, preferably decades ahead of time.
We can then use a number of different techniques. It might be a kinetic impactor firing a spacecraft into the target that produces a tiny change in its momentum and therefore, its track, but magnified over a number of years, it can be enough to miss the Earth. We could use something like a gravity tractor where you bizarrely use the gravity of the spacecraft itself, take it close to the object and then fire the rockets very, very gently and use that small gravity of the spacecraft to just gradually change its orbit. Both of those techniques will take a long time and we may not have that level of warning. In the end probably, the only alternative is to let off nuclear weapons very close to the object, vaporising some of the material in a jet effect, and then move the target.
Dominic - I guess it's reassuring to know that those options are there. Thank you very much, Simon. That's Simon Green from the Open University.
38:14 - Mining Asteroids for Mineral Wealth
Mining Asteroids for Mineral Wealth
with Chris Lewicki, President of Planetary Resources Inc; Rick Tumlinson Chairman of Deep Space Industries;
The majority of the asteroids we're acquainted with have come to us. But now, a number of enterprising individuals are developing ways to harvest and mine asteroids for the minerals that they may contain. Chris Lewicki is the President and self-appointed Chief Asteroid Miner at the Seattle based company, Planetary Resources Inc; and Rick Tumlinson is the Chairman of Deep Space Industries. We'll come to Rick in just a second, but let's kick off with Chris. First of all Chris, why do you want to mine asteroids? What's the appeal of doing that?
Chris L. - Asteroids are a very exciting destination in our Solar System and from the intro that you just heard from Simon, of course, they've been out there for some time. They're the leftover things that formed our planets and they have a number of very useful and very valuable resources on them that will be important, not only here on Earth, but as we continue to expand out into space.
Chris - When you say resources, what sorts of things are we talking about that we can get from an asteroid that we may not be able to obtain more easily on Earth?
Chris L. - The resources that you may consider bringing all the way back to Earth are such elements as the platinum group metals, and these are elements that during the formation of the Earth actually sunk down to the core, and are relatively depleted on our planet. There are other resources though in addition to those that are equally exciting. Things like the iron, nickel, and cobalt that can be used for the manufacturing of space structures and then a very important resource to us all in space is water. We have enough water here on the planet and we would never bring water back to supply Earth from space, but not having to transport that water out into space is very valuable, and to be able to use the material, it's already out there in space is really the great opportunity that's awaiting us.
Chris - How much have you had to raise to get your venture going in the first place?
Chris L. - Our company has been around for a few years. We just announced ourselves last spring and in starting any venture as audacious as asteroid mining, you certainly require a lot of money and some visionary individuals who are willing to take that first step. So, we've been very fortunate to get gentlemen like Erich Schmidt, the Executive Chairman and Larry Page, the CEO of Google, as well as other Americans like Russ Perot and two-time Space Live participant Charles Simonyi. They've given us a great start down this path of building really a new industry in the next phase of space exploration.
Chris - Rick, what evidence is there that this is a viable business proposition for both deep space industries - your company and also for Chris Lewicki, I guess you're competitors?
Rick - Well, let's put it this way. As Chris was mentioning, the large early market for us is going to be what we do with these resources in space.
Say if your listeners would walk outside of their homes and grab a pound or a kilo of let's say dirt, if that were delivered in space right now, that would be in the range of $10,000 for that to be carried into space. And that's just dirt.
So pretty much anything that you can provide up there, any resources or materials that we can create in space are going to be valuable. On Earth, we measure ore in few thousand dollars per tons of ore. In space, the value of it goes up incredibly and once we being to provide those resources in space, and begin to learn how to refine and process them, then we can begin to build different sorts of structures, we can support missions, let's say, the space agencies want to go to Mars, we can be their oasis, we can be provide hardware using some of the manufacturing processes.
So, those are wide range and then there'll be the kinds of activities that begin to bring back to the Earth, whether it is shooting down platinum, etc. We're not so focused on that, but basically, at the core of it, we have to admit that Chris and their founders, and our founders are true believers that this is the next frontier. And we've got to figure out a way to make it pay or nobody stays. You know, no bucks, no Buck Rogers. So, we're out there working that.
Chris - Well, let's talk practicalities for a second. So Chris, where are you going to get these asteroids from?
Chris L. - Well again, as Simon described, we have almost 10,000 objects that have been discovered to-date, many of them in just the last 15 years that are orbiting the Sun in relatively close proximity to Earth. In many cases, these near-Earth asteroids are even more accessible and easier to travel to than it is to land in the surface of the Moon.
Actually, about 15% of them or almost 1500 objects are relatively easy journey away from what we have learned about robotically exploring space in the past 50 years. So, what is necessary in the next few years is to really identify those worthy candidates that have the appropriate resources on them, that have the appropriate orbits and the schedule to get to and from them, and to begin and continue to develop the technology and the business environment to develop and produce these resources to a market.
Chris - And Rick, how are you actually going to get to these objects and then once you get there, get stuff off of them, and then what are you going to do with it?
Rick - The two companies of course have different approaches. In our scenario, we're launching small prospecting probes called Fireflies about the size of three laptops, and they'll do flybys and begin to help us characterise or learn what the different types of asteroids are made of so we could compare that with observations made here in the Earth or using Hubble or whatever. Then we will send out what we call Dragonflies which will bring back a few kilograms so that we can begin learning how to utilise the materials and probably, sell a little of that to scientists. Once we get to that point then we get into what we call harvesters which are using different source of thrusters, ion or plasma thrusters. Fairly small relative to the size of the asteroid, but it doesn't take much. If you push a little bit over a long period of time, you can move something very large a long distance.
As Chris was saying, once we're in space, we can do a lot that you can't do if you have to go down into what we call gravity wells which is on the Moon and Mars. Once we're out there, if we have the time and the patience, we can move very large things in a very long way. So for example, we might move an asteroid into a little orbit and there, if anything goes wrong, it falls harmlessly on the moon. So, it's not a safety issue and then we can begin extracting the actual industrial process.
Chris - It's reassuring to think that you've thought about what might happen if you accidentally create a giant traffic jam or a collision in space. Chris, is there not a good reason to say, take the refinery to the asteroid and then bring back just the stuff you want?
Chris L. - Well certainly, there are a variety of options there we can have. We too, like Rick had mentioned, are in the prospecting phase of sending out the geologists, so to speak to these things to identify the resources and then through a step-wise process, continuing to educate what it will take to acquire the resources, what the resources exactly are, and then as you said, decide whether the next most appropriate action is to bring some of that resource back to the Earth's proximity where you might have more infrastructure available to help develop it, or in other cases, do some local refining of the resource, at the asteroid and then just ship back to the point of use, whether that's a fuel depot in Earth orbit, or developing space station, or maybe even destinations in the future out to Mars and elsewhere that you would just send really something that is closer to a finished good or a raw material.
Chris - And just to finish off, what is the timescale on this? I mean, Rick, when are you aiming to actually have things airborne and samples coming back?
Rick - Our goal as a company is to try and get something popping up around 2015, the actual Fireflies and part of that is to demonstrate our capability, to demonstrate the technology, to start testing them, and seeing how operable they are. The actual large scale mining activities, I don't know exactly Chris's company schedule, but I don't see that happening until 2020 and beyond the serious mining sorts of activities. But keep in mind, even here on Earth, if somebody is pondering a large scale project, you know, be it a major dam or mining, or other large scale project, timescales of 10 years or more are quite common. So, it's not that out of the range.
47:41 - How to make a Solar System
How to make a Solar System
with Alan Jackson, Cambridge University
Our Solar System contains a great diversity objects from the Earth we're standing on to asteroids that as we've just heard, there are companies hoping to mine. These objects range from massive gas giants like Jupiter, right down to clouds of microscopic dust. But we're not sure how it all formed. Research using computer models is helping to shed some light on this problem and to find out how, Ben Valsler spoke to Alan Jackson, a PhD student in the Institute of Astronomy in Cambridge.
Alan - I've always been interested in asking how did Earth get here? Why do we have this nice planet we live on? How do we end up with planets like Earth? Are there likely to be any others?
Ben - Are there any examples out there in the universe that we can actually use to see this happening or do we have to rely on what we see here in our own Solar System and extrapolate backwards?
Alan - There are some places where we think terrestrial planet formation is going on. All of this is quite new in terms of people going out and looking at it. We're probably certain there must be places that it's happening. We're still trying to find them. The first extrasolar planet around a star like our Sun was found I think in 1995. So, it's really not that long ago at all.
Ben - That's not given you a lot of time to find examples that you can use!
Alan - No, exactly. The first one was in 1995. I think the second one was in 1997. It's only really in the last 10 or 15 years that's really beginning to pick up speed.
Ben - So, in the absence of systems that we can look at and watch it happening, how do you actually start to understand the processes that are going on?
Alan - If you can't see it going on, then what you have to do is look at what you end up with. We know to a reasonable degree what they must have started like because we can see protoplanetary disks, these big disks of dust and gas that are around young forming stars. How do we get from that to planets?
Ben - And how do you fill that gap in? What do you have to use to actually start answering that question?
Alan - Lots of computer simulations. For the very early stages where you're looking at the gas and dust and how that gas and dust starts to collapse down to produce some little asteroid-like objects. Because that's mostly gas, we'll be looking at fluid type situations. Later on, when the gas is gone and you just have lots of bits and pieces of rocks that have stuck together, and you've got various different size lumps then you're looking more at just stimulating those individual particles and colliding them with each other.
Ben - So you have to rely on some basic physics to tell you what should be going on.
Alan - Yeah.
Ben - But then it must be very difficult to integrate and to work out when we stop using the physics of fluid dynamics and we start using gravity and other accretion models.
Alan - It is, yes. Guessing the boundary between them is quite difficult. Sometimes they don't quite match up properly. It's not particularly uncommon for people or different groups to be simulating different aspects of the evolution of these type of things, and the results of one group doesn't quite match up with what other group is doing. Basically, you just need to talk to each other and try and work out what's causing it to not match up. If you can do that then do it again, it does it match up? Yes? good. No? Okay maybe not, lets try again.
Ben - So, that way, lots of different groups all over the world can actually refine their models until we come to an understanding of what we think really has happened?
Alan - Yes, and then of course there's the observational side which is, now we need to try and go and find something out there that's in the process of doing this, and see if it actually looks like that.
Ben - This is obviously a very good way to make very well-refined models that show how this cloud of gas and dust becomes the planets and the objects that we know about. But unfortunately, things are never quite that straightforward and we know from looking at the planets in our Solar System that there has been some almighty collisions and hails or new objects. How do you account for the actual quite destructive nature of our Solar System?
Alan - It's one of the big problems actually with these things, getting the planets to not just blow each other up and actually, it's with the smallest objects that this is the biggest problem because obviously, the smaller something is, the less gravity it has. So, getting them to stick together without destroying each other is quite hard. Once you get up to things the size of Earth, although you do get these incredible collisions that are very, very violent, because the Earth is - comparatively speaking - quite big and has a lot more gravity holding it together, it's a lot more difficult to actually completely destroy it. It can happen, but it's a little bit more difficult to do.
Ben - How do we account now for the diversity of objects that we see in the Solar System? We have gas giants, we have terrestrial planets like Earth and Mars, but we also have these bands of asteroids that clearly haven't accreted into a planet in the same way that Earth has. How can the models make sure all of those fit and are in the right place?
Alan - Well, with the asteroid belt, the main reason that we have the asteroid belt is Jupiter. If Jupiter wasn't there or hadn't formed where it is then probably, the asteroid belt would either have like accreted on to Mars and so Mars would be bigger, or it would have formed a terrestrial planet. But because Jupiter is so very massive, it stirs up the material nearby to much higher velocities, so that early process that I've mentioned where trying to get things to stick to each other is a bit more difficult, it just doesn't happen.
53:49 - Can you create a miniature Mars at home?
Can you create a miniature Mars at home?
Chris - My name is Chris McKay. I'm a Planetary Scientist with NASA Ames Research Centre. I'm interested in Mars and particularly the question of life on Mars. The question for today is, can plants grow on Mars and how could we simulate that here on Earth? Well, I think there's two parts to that question. The first part is, the soil on Mars. Could plants grow on that soil? Well, the best analogue we have on Earth for Mars soils is volcanic rocks - soils that have been produced from volcanic rocks. So, we could go to Iceland or Hawaii and collect some soils that have come from ground of volcanic rocks and use those as Mars analogues. And folks who have done that, it's pretty easy experiment to do and try it. I think you'll find that most plants go fine in that kind of soil. The other question though is about the environment of Mars. The temperature is very low, the atmosphere is very thin, and the atmosphere is carbon dioxide, very different from the Earth's atmosphere. We can simulate those in the laboratory of course with a vacuum chamber and a big freezer. We can get a sense of how to simulate those at home in your freezer. It's cold, not as cold Mars, but almost as cold as Mars, and certainly, too cold for plants to grow. We can also simulate the low pressure by taking a small jar, putting water in it, boiling the water which will drive off the air, drive away the air, fill the atmosphere with water. We then seal that small jar and cool it. The water will condense creating pressures very much like the atmosphere of Mars. So, we can create low pressure environment, put in the freezer, now you have low pressure cold. We want to have CO2 in that as well. Instead of water, maybe we could try something like carbonated drink like Sprite. Then as it boils, it'll put out water and CO2, drives away the air, we seal it, the water condenses creating a low pressure and there's a small amount of CO2 left. Voila! A little bit of Mars in the freezer, low pressure cold! Plants won't grow in that. We know that in order for plants to grow, it's got to be a little thicker, a little warmer, maybe something in the refrigerator instead.