Several privately-funded space companies are locked in a race for the trillions of valuable precious metals to exist in asteroids. Britain has now entered the race, with the Asteroid Mining Corporation becoming the first of these new companies in the country.
In theory, the business case speaks for itself – the incredible cost of space missions would be more than compensated. But how is it going to break down an asteroid? How do you choose one? These are some of the questions I was thinking about when I did a feasibility study for the company.
Asteroids can be classified as consisting of carbon, silicon or metal. Mining companies are particularly interested in metallic asteroids, but their compositions are still not well understood. Scientific investigations of asteroids ̵
So far no asteroid has been directly sampled. Telescope observations have been made along with analyzes of meteorite fragments of asteroids that have fallen to Earth, and the data suggest that a small percentage of asteroids contain high concentrations of valuable metals such as platinum and gold. So, before we dream of spending our trillions, we must first look for suitable asteroid mines.
So far, more than 750,000 asteroids have been identified. The vast majority can be excluded immediately as they are found in the asteroid belt between Mars and Jupiter – too far away to be considered potential mine targets. Instead, we should focus on the asteroids near Earth, which limit the search to about 17,000 targets. Satellite observations with a telescope and spectroscopic instruments are required for constriction
A spectrograph analyzes the sunlight reflected from the surface of an asteroid by being decomposed by the wavelength. This allows us to determine the composition of the surface. For example, if the light from an asteroid appears reddish in color, this indicates the presence of iron and nickel clusters on the surface. Platinum is normally found in such clusters on Earth, so we can conclude that it might occur in these asteroids. However, we can only observe how light interacts with the surface of the asteroid – not with the underlying layers. And the surface could have been altered by collisions with other solar system objects or by radiation.
When choosing an asteroid we need to find out if it is sufficiently large and if it has a sufficiently high concentration of asteroids valuable and widely used metal. Is it moving too fast? How far is it in orbit and how long will it take to send a probe?
According to Professor Martin Elvis, an astrophysicist at Harvard University, an asteroid that is worth mining has a market value of $ 1 billion. To meet this requirement, the asteroid must have a diameter of more than 1 km, contain more than 10 parts per million platinum and have a velocity relative to the earth's velocity of less than 4.5 meters per second. There are more than 17,000 near-earth asteroids, but how many of them fit the bill?
Professor Elvis made a theoretical estimate based on probabilities and assumptions. Of all the meteorites that fell to Earth, about 4% were metallic. We can therefore assume that 4% of the near-Earth asteroids are also metallic. Considering these and other probabilities, only 10 asteroids remain, which – theoretically – are economically viable and practically degradable.