28-09-2020 | | By Robin Mitchell
As electronics continue to become increasingly more important in everyday life, so is the ability to produce electronic components. With the supply of minerals on Earth having a finite size, some are worried that Earth will soon run out of critical resources such as platinum and lithium. What are asteroids, what are they composed of, and could they be the key to providing humanity with a near-infinite source of minerals?
Since the introduction of the first commercial circuits, electronics have become incredibly advanced with silicon dies having billions of active components, resistors the size of dust specks, and capacitors that can hold obscene amounts of charge for their size. However, many of these components rely on minerals that most will never have heard of for them to be able to work. Basic components such as resistors and capacitors use common materials including iron, carbon, and aluminium, but components such as LEDs, silicon dies, and thin-film displays use lanthanum, cerium, neodymium, and europium. While many of these minerals fall under the “rare-earth” category, that does not necessarily mean that they are rare; but many are.
Minerals that are rare by nature are uncommon in the crust, and mass industrialisation is quickly using up remaining reserves of these minerals. However, it is important to understand what reserve means and how reserves are calculated. Let’s take Uranium as an example to understand this concept better; as things currently stand, there are 80 years of Uranium reserves left. Now, this does not mean that all the uranium will be used up globally in 80 years, this means that at the current price of Uranium, proven sources will continue to supply Uranium at a profitable rate for 80 years. When all reserves are used up, the price for that mineral increases, and this makes areas that used to be unprofitable more profitable, thus generating new reserves.
However, there is another aspect to resources that need to be considered; environmental damage. A good example to demonstrate this is Lithium. While Lithium is rather abundant in the crust, it is spread very wide, making most crust uneconomical to mine. If all cars on earth went electric, the proven reserves of Lithium would run out in 3 years. Of course, new reserves would be made available, and this would extend the ability to use Lithium in industrial practices. However, mining Lithium has a massive environmental impact and sees vast amounts of land destroyed and made toxic due to by-products in the extraction process. The same applies to many rare minerals; many tons of earth is needed to get even the smallest quantity.
Asteroids are small cosmic bodies that orbit a star and can range in size, density, and composition. One of the largest asteroids in the Solar System, Vesta, has a diameter approximately 330 miles, while some of the smallest can be just two meters across. Asteroids mostly consist of rock as well as minerals, but their exact composition greatly varies. For example, M-type asteroids are those that mostly consist of nickel-iron, while C-type asteroids consist of clay and silicate rocks. Other minerals that are often found in asteroids include gold, cobalt, palladium, platinum, and osmium.
While asteroids themselves may contain trace amounts of rare minerals, their size and lack of an ecosystem would allow for a mining operation to destroy an entire asteroid with no repercussions. Asteroids are also plentiful in the Solar System, and would most likely provide humanities resource needs for millions of years. For perspective, the total weight of the asteroid belt is only 3% that of the moon, but that is still 2.39×1021 kilograms. Even then, that is only the asteroid belt and does not consider stray asteroids that orbit the sun, planets, and rings around Saturn / Jupiter.
So if Asteroids are abundant in resources, why don’t mining companies send rockets to space armed with pickaxes and spades? Asteroid mining, a technology that is still to be even experimented with, is no small feat. The first major hurdle to such an operation would be to make the entire process economical. This includes training space miners, development of cheap rockets, equipment that can mine on an asteroid, process the minerals, and then send them back to earth. So far, none of these stages has been achieved, and the comparatively cheap mining practices on Earth will keep mining on Earth.
The second major hurdle is moving asteroids to an economic location. An asteroid in the asteroid belt is probably too far away from Earth to work on, and thus needs to be moved closer to Earth (most likely in orbit around the earth). Small asteroids may be easy to move, but large asteroids with sizes in the km may require unimaginable amounts of energy to move. Highly efficient ion engines or solar sails can provide economical solutions, but these may take decades to work.
The third major hurdle is the economic impact of the sudden abundance of materials. For example, the asteroid Psyche 16 has precious minerals that could total value of $700 quintillion. However, that is not how mineral prices work, and as a mineral is made abundant, its value drops. Thus, if this asteroid was completely mined, and its resources put into circulation, the total value of one of the largest asteroids would significantly drop.
Electronics are highly dependent on rare minerals that are becoming increasingly difficult to find on Earth. Even if more proven resources are found, global environmental action may restrict or prevent those resources from being accessed. If this happens, asteroid mining may be the key to sustaining economic and technological development. However, to achieve such a task, many technological hurdles need to be overcome, and only a few may be brave enough to take on such a job.