Space dust and ethics – Future Mining Conference day 2

Today started at the much more relaxed 8:45 am – not because the conference organisers felt like that was a more appropriate time, but because our Minister for Industry, Innovation and Science decided he couldn’t make it. Or something. I felt doubly snubbed as Pyne is my local MP AND a graduate of my school. C’mon Chris.

There were a lot of great talks today, (and definitely more of a space theme) so I’ll just summarise some of my favourites.

The morning started off with a presentation by Rene Fradet, Deputy Director of NASA Jet Propulsion Laboratory (JPL), on the potential for a common journey between exploration/science and mining in space. My supervisor introduced me to Rene over lunch and we were able to broach the possibility of visiting JPL in California (or even spending some time researching there!?) and collaborating with their scientists, some of whom are also working on mapping the interior of asteroids with geophysics.

Dr Seher Ata from UNSW spoke about ‘Resource recovery in space’, or more specifically, how to process and separate materials in space. If we want to to mine and then utilise material in space without having to bring it down to Earth, we’ll need to develop ways to process and separate materials in a microgravity environment. Many terrestrial separation methods such as froth flotation and magnetic separation rely on gravity. For example, using magnets to separate out magnetic material is only worthwhile if everything else is being pulled away by gravity, and bubbles won’t rise in a liquid, which makes froth flotation difficult to impossible. One audience member suggested centripetal force, but as you add more moving parts you increase the chances of something going wrong. I wondered aloud why we couldn’t utilise that lovely vacuum we have around us in space to induce some kind of air flow/movement and use that instead of gravity. Apparently that wasn’t actually too bad an idea, and I was told to look into it. Geez, I’m just a geophysicist! Let me know if you are a metallurgist and have some clue on how to advance this crack pot idea.

Another good talk was by Dr Jeff Coulton from UNSW Business School about an MBA elective he ran on costing resource projects. To make things a little more interesting, he gave the students a choice between three off-Earth mining projects; mining Ceres, mining the Moon or mining a near Earth orbit asteroid (NEO). The students were mostly from an IT or finance background, and so had little technical experience in terms of space science or engineering. They were told to assume the project was technically feasible, and to make assumptions on costs, resource values, demand etc. This simple experiment suggested that mining the boon had an initial capital expenditure of $9 billion (Au) and a net present value (NPV) of around $-450 billion. So you would lose $450 billion. Not very attractive. But – mining Ceres had a capex of around $22 billion and an NPV of around $80 billion, and mining an NEOhad a capex of just $492 million and an NPV of $295 million. Of course, these assume technical feasibility for these projects, which isn’t necessarily true at present, but what they demonstrate is a strong reliance of economics on the choice of discount rate and selling points.

I was pleasantly surprised to see a few talks on space law, but just plain surprised to see a presentation by an academic on space ethics. He opened his presentation with “As a humanities scholar I’m going to do something that annoys non-humanities scholars, and that is to read to you.” And he did just that. But I must say it was an enjoyable talk which got me thinking about a few things I hadn’t considered. For example, Dr Thom van Dooren focussed on the point that the economic, environmental, technical, scientific and cultural concerns related to space cannot be addressed individually, they are all entangled. Despite the low chances of humanity establishing a backup planet elsewhere, the implications for our survival and expansion are profound. One way to look at this is called ‘worlding’ – “What kind of world are we creating and what are the implications for whom?”

For example, mining helium-3 on the Moon might have obvious positive implications for some, but for others, damaging space environments may be seen as intrinsically wrong, and for others still it may be seen to be offending deities. How do we balance these concerns against others? Van Dooren argues that their concerns are not null.

Professor Steven Freeland began his presentation on space law with an amusing story. He was reading an article about space law in the Wall Street Journal. Oh great, he thinks, this will be interesting. Then he sees the title: “If a Martian crashes into your spacecraft, who is liable?” After a theatrical groan, he decides he can make a better summary of space law than the article.

Dr Alice Gorman gave a unique account of the importance of cultural heritage on the Moon and the implications of Moon dust, which, surprisingly, is actually a pretty big problem. Lunar dust is extremely sharp and abrasive due to the lack of erosional processes such as wind and flowing water. The grains can be highly electro-statically charged, and can levitate, especially when the terminator (sharp night/day boundary on the Moon) passes, due to the rapid change in temperature. Some particles are even assumed to reach lunar escape velocity speeds when human activity such as rover are in the vicinity. Imagine one of these dust grains hitting you at escape velocity!

Images of microscopic lunar dust. Image from
Images of microscopic lunar dust. Image from

Widespread mining of the lunar surface may even create an upper atmospheric dust layer, which could prevent aforementioned particles at escape velocity from actually leaving the surface. The implications of such a feature forming were left for us to imagine!

Apologies to any presentations that I missed, as they were all excellent talks. Leave a comment below or email me if you’d like to hear more about any of the talks, and I can go into more detail and discuss. A list of conference papers can be found via this link.

Tonight featured a presentation by Brian Muirhead of JPL, who is the manager of NASA’s Asteroid Redirect Mission (ARM). I’ll do a separate blog post about that as it’s a mission I’m really excited about, but for now I’d just like to share this very amusing and poignant image.


Maybe the dinosaurs would have survived if they had put more funding into their space program? Let’s not make the same mistake.

The Future Mining Conference finished up today, but the Off-Earth Mining Forum will continue tomorrow, featuring more talks from asteroid mining start ups and space scientists/engineers.

Until then.

Landing on a comet

The AusIMM Future Mining Conference kicked off tonight with a presentation by Professor Monica Grady about the Rosetta (accompanied by the Philae lander) mission to comet 67P/Churyumov-Gerasimenko (which I’ve done a post on here). If you don’t know Monica, here she is celebrating Philae’s successful landing on 67P. Unfortunately for her, she hasn’t realised that it promptly bounced off, but more on that later.

Professor Monica Grady demonstrating gravity assists.
Professor Monica Grady demonstrating gravity assists.

“Why go to a comet?” asks Professor Grady at the start of her talk. Comets contain carbon and water, the building blocks of habitable worlds. Quite possibly, a good deal of our carbon and water here on Earth came from comets. The more we understand about comets the more we understand about our own origins.

In 1986 three probes were sent to 1P/Halley – Vega 1, Vega 2 and Giotto. This was the first comet we got up close and personal with, but we didn’t attempt landing. Then in 2006 the Stardust mission visited 81P/Wild 2, but again, no landing. Stardust did, however, collect dust from the comet’s tail and return it to Earth, allowing us our first glimpse at cometary material. However, due to the capture mechanism, carbon was difficult to capture and so we couldn’t analyse it. Finally, after 10 years in space and using gravity assists from Earth and Mars, Rosetta reached 67P.

Due to the nature of space mission design, the on-board instruments need to be finalised several years in advance so they can all be properly integrated together. As a result, the instruments being used now to study 67P were designed in the late 1990’s / early 2000’s, which by today’s standards of technology is ancient!

Comet 67P/Churyumov-Gerasimenko
Comet 67P/Churyumov-Gerasimenko. Image from

For the purposes of planning Philae’s landing, scientists and engineers assumed that 67P was roughly spherical and had an average comet density. In 2014, we got our first close up picture of 67P. Definitely not spherical. This meant we severely underestimated the gravitational pull of the comet. But that’s ok, the engineers said, that’s why Philae has harpoons to tether to the surface!

10 potential landing sites were selected. Care was taken to pick a spot that wasn’t too sunny (so the equipment wouldn’t fry from the intense heat of the sun), not too dark (so the solar panels could charge), not too steep and not too rocky (so Philae wouldn’t fall over). How did they go? Well, at least the equipment didn’t end up frying.

The below picture is the last image taken of Philae as it left the Rosetta craft. With much excitement and anticipation, the leadership team, 11 principal investigators and the media waited in a conference room for the fateful landing.

The last image taken of Philae as it leaves Rosetta.
The last image taken of Philae as it leaves Rosetta.

They waited 7 hours. Entertainment was provided by promotional videos such as this one (featuring ‘Littlefinger’), which I’m told got a little tired after the third time.

The investigators knew Philae bounced immediately. For a split second, they started to receive results from the comet surface. As soon as celebration erupted from the conference room, the data feed stopped. Not a good sign.

This cartoon from ESA provides a (somewhat simplified) explanation of what happened.

I could go into greater detail about an incredibly detailed presentation, but I need to be up in 7 hours to register. Who starts a conference at 8 am?

Until tomorrow.

How to make a comet

Hey space lovers! I’ve recently signed up to be a member of The Planetary Society and if you should too if you aren’t already. Not only do you get an excellent t-shirt (see below) and a quarterly issue of The Planetary Report magazine, you are funding space advocacy and adding your name to an important body that will promote space exploration.


Have you ever wondered why comet 67P looks the way it does? It’s a strange shape and looks a little like 2 bodies that have been fused together, but to the researcher’s surprise, the cometary activity appears to originate in the neck. Why? Rapid temperature change in the neck, causing cracks and inducing volatile loss. Check out Emily Lakdawalla’s blog entry for the full spiel!

Comet 67P/Churyumov-Gerasimenko. Image from
Comet 67P/Churyumov-Gerasimenko. Image from

Pluto, measuring gravity with probe swarms and more!

A lot of exciting space science news coming in this weekend! Lets start with this project brief from Johns Hopkins University.

The proposal is to use a series of orbiting probes and a mothership to measure the gravity field of an asteroid or comet, and use this information to model the internal structure. Modelling the interior of small planetary bodies is something that we haven’t achieved yet as a species, simply because most of our exploration tools focus on large scale and surface features. We haven’t been able to put a drill hole into the centre of an asteroid yet!

Scientists are turning to remote sensing techniques like gravity, ground penetrating radar and radio tomography (think penetrating an asteroid with lightwaves of different frequencies and measuring the signal returning signal bouncing off different internal structures) to cheaply gather data on an asteroid’s interior.

In the above proposal the mothership will precisely monitor the position of the orbiters as they rotate the asteroid. Even a small change in orbit will reveal changes in density which can be caused by heavier or lighter material and empty spaces within. The combined data will be used to build a picture of the asteroid’s interior. This technique is already shown to be feasible through a series of simulations.

The benefits of such a project include the mothership being able to perform other experiments simultaneously, even leaving room to send a lander to the surface.

My only concern is in accurately tracking the position of the orbiters with respect to the asteroids surface. On Earth we need 4 GPS satellites to provide accurate location coordinates.

In other news, an incredible new photo reveals signs of geological features on Pluto, making a geophysicist like myself giddy with excitement. Even with a resolution of 27 kilometres, breathtaking new features can already be made out.

I think my reaction can be neatly summarised by this photo of science team members.

While it is unlikely that Pluto is still geologically active due to its small size, it seems apparent that it underwent a series of events leaving clues on its surface to its past.

As New Horizons principal investigator Alan Stern said, “After nine and a half years in flight, Pluto is well worth the wait.”

Different materials reflect various wavelengths of light in different proportions. As a result, each material has its own characteristic spectral signature.

Even with the most advanced telescopes, the light from distant planets beyond our solar system constitute a single pixel. This makes it hard to look for life, as the light signature from a planet gives us only the average of the near side of the planet.

Researchers from the University of Washington and the Virtual Planetary Laboratory published a paper in May in Astrobiology. They have found that if an organism with nonphotosynthetic pigments (which use light for things other than energy) cover enough of a planet’s surface, their influence on the spectral signature could be strong enough to be detected by a new generation of telescopes currently in development.

This possibility has been overlooked in previous searches for life, and while there are some difficulties with this method, it certainly broadens our ability to detect life at great distances.

A link to the original paper can be found here.

Until next time.

Rosetta and 67P

67P/Churyumov-Gerasimenko, named after its founders by the same names, is rapidly approaching its closest point in orbit to the Sun. At almost 38 km/s to be precise.

Comet 67P/Churyumov-Gerasimenko
Comet 67P/Churyumov-Gerasimenko. Image from

Last November, the Rosetta spacecraft’s lander, Philae, became the man-made object to perform a soft landing on a comet.

And what a landing it was! Philae was unsuccessful at anchoring itself to the surface of the comet with its landing harpoons and bounced twice before coming to a halt in a dark zone. This was a problem as the lander couldn’t charge its batteries as well as planned using solar panels, and went into hibernation 3 days after touchdown.

Although Philae made contact at a very low speed, the low gravity on the comet (around one ten-thousandth that of Earth), meant that a small bounce was disastrous.

One proposed theory for the greater than expected ‘bounce factor’ is that the surface of 67P was elastic, with a hard crust under a metre thick overlying an elastic material (S. Ernst pers. comms.). This made me think of the recent announcement that the mysterious ‘craters’ on the surface are created when porous rocky material which has lost its water-ice due to outgassing. Eventually this porous rock can no longer hold its own weight, even in the low gravity of the comet (suggesting high porosity indeed… and a very high current or previous water content for the comet overall!), and it collapses, creating a sinkhole-like feature.

Perhaps the proposed ‘spongy material’ causing Philae to bounce is the same porous rock that is causing these sinkholes?

If so, is the whole surface of the comet poised on the brink of collapse with high porosity? Or did Philae get unlucky and land on a soon to be sinkhole?

These are the questions that excite me about space science. Part of my PhD will involve developing new and novel ways to test various models for the structure of asteroids and comets. Currently I’m looking at seismics and ground penetrating radar, but endless possibilities abound!

Until next time.

Edit: This article suggesting that 67P could be home to microbial life refers to an organic rich crust which is being constantly replenished. The presence of this crust and the replenishment of water (by outgassing from the deeper ice?) would support the above hypothesis!

Second edit: The Skeptics Guide to the Universe has stated that the original scientific research the above article was based on doesn’t actually make any claim to the existence of life on the comet. It just goes to show that one should always read the original science before commenting, as science journalism does get it wrong from time to time!