The journal Nature recently published an article that argued the gold and silver found on Earth should be much more abundant than they are. Whilst both metals can be found scattered throughout space, they are relatively rare to find on Earth compared to other elements, and the lack of gold in particular has been a growing concern amongst the mining industry. Whilst the metal has always been scarce, it is being found less and less often which will certainly mean an increase in price as time goes on.
Bernard Wood, a geologist from Oxford University, argues that ‘The silicate Earth is strongly depleted in moderately volatile elements (such as lead, zinc, indium and alkali elements) relative to CI chondrites, the meteorites that compositionally most closely resemble the sun’. His paper studies the lack of gold and silver found on the planet, concluding that the way it was formed is the cause of this.
‘Earth’s Volatile Contents Established By Melting And Vapourisation’, as the paper is titled, looks at the formation of the earth and argues that the gold that would have been present at one time turns to gas once it reaches a particular level of temperature. Using a furnace, Wood studies the effects of heat on a model version of an early Earth, using temperatures of up to 1,300 degrees Celsius, as well as adding elements such as carbon dioxide, carbon monoxide, basaltic rock and zinc oxide to the process, to mimic the formation of the planet.
‘Our experiment shows that melting processes explain the pattern [of volatile depletion] perfectly’, concluded the study. ‘We find that the pattern of volatile element depletion in the silicate Earth is consistent with partial melting and vapourisation rather than with simple accretion of a volatile-rich chondrite-like body’.
Although magnetic materials and magnetic fields are naturally occurring, the most powerful magnet in the world is man-made. Reaching a huge 100 tesla, the magnet is over 2 million times more powerful than the Earth’s own magnetic field, and sits in the National High Magnetic Field Laboratory (NHMFL).
In March 2012, researchers at the facility were able to claim that they had created the strongest magnetic field ever, that was non-destructive. The power of the magnet is over 100 times more powerful than a typical junkyard magnet often seen moving cars or heavy pieces of equipment, and 30 times stronger than the magnetic field that comes from an MRI scan.
The Los Alamos facility is one of three sites that form the NHMFL and the current home of the colossal magnet. Weighing in at 18,000 pounds, and with a huge 1,200 megajoule motor generator, it provides researches with a unique tool to use in their study of materials and the effect of magnetic fields on them. Although other attempts have been made to build similar magnets, none have successfully been able to emit a magnetic field without destroying themselves. As such, the magnet at the Los Alamos site is called a multi shot in reference to its ability to be used over and again – as often as once an hour.
The magnet is composed of four electrical circuits and is surrounded by liquid nitrogen, which keeps it at a cool -198.15 degrees Celsius. This is inside a container known as a dewar and it is used to keep the magnet cool and prevent it from overheating. The magnet is so strong that it also emits a loud shrieking sound when in use, caused by the electrical current modulation. It can only be kept on for a few seconds.
Asteroid mining is the removal of raw materials from an asteroid. It is not something that has yet been accomplished, but there have been many proposals and theories on how this could become possible and there are several companies in existence dedicated to this purpose, including Deep Space Industries and Kepler Energy and Space Engineering.
There are thousands of asteroids that pass close to the Earth, and could potentially be used for the purpose of mining. The materials that can be contained in an asteroid include gold, iridium, cobalt, tungsten, aluminum and nickel, as well as numerous others that we use on a daily basis. With modern industrial processes continually depleting out natural reserves of materials such as zinc, tin, lead, silver, gold and copper, the possibility of them being found elsewhere is certainly appealing and one which we should not dismiss. Whilst this may sound quite far-fetched, Chris Lewicki, the president of Planetary Resources and one of their chief engineers, puts it into perspective. ‘It is natural to doubt when you don’t know much about it. Most people read the headline and make assumptions. We are only repeating what has been done throughout history, just in a new environment.’
The new environment, however, that we are looking at is one which is hostile and dangerous, and that we have barely begun to discover. Despite this, those behind the concept of asteroid mining believe that it has the potential to shape our economy for the next century and will be revolutionary in developing our knowledge of space. They emphasise the importance of not only bringing materials back to Earth, but using them in space for further construction and discovery. Space Foundation, a global non-profit organisation believes the results could be ‘revolutionary in benefits to space exploration, and all of us on Earth’.