Exploiting asteroids’ natural resources is not in itself a new idea. By 2070, the world population will have reached 10 billion. Therefore, for several years, scientists have posed the question: since resources are already lacking onEarth, why not look above our heads for what is disappearing below our feet?
This is the starting point of a study, published in the magazine Acra Astronautica. Inspired by the idea, the lead author Minghu Tan, PhD student at the University of Glasgow, suggests going a bit further: keeping the asteroids at our fingertips.
By pushing the asteroids through a series of shocks, it would be possible to divert them from their natural trajectory and put them in terrestrial orbit. Once the asteroids are orbiting the Earth, astronomers hope to send empty special vehicles towards them to carry out drilling.
Gold and platinum mines
The asteroids have precious resources. They are constituted mostly of nickel, iron, gold and cobalt. Platinum is also found in asteroids in abundance, one of the most precious metals on Earth. But also water, which Minghu Tan hopes to break down into hydrogen and oxygen, which can be reused as fuel for future space missions.
But how to direct the asteroids towards Earth? The method is simple: the researcher suggests using aero-braking. This manoeuvre is already used largely in orbital mechanics, mostly to ground probes. By using the forces of friction exerted on a planet’s atmosphere, objects can be slowed down.
A mixed reception
While Minghu Tan’s proposition is still only in the study phase, the idea to voluntarily direct asteroids towards Earth has received a mixed welcome from the scientific community. One of the main concerns is the risk of an asteroid falling on Earth.
In fact, no asteroid is the same and the journey of these objects could thus be extremely difficult to control. To this, Minghu Tan responds: 'in this study, we will only consider asteroids with a 30-metre diameter.' An asteroid of this size would evaporate at a lower atmosphere if it ended up falling from orbit.
Dr Sherry Fieber-Beyer, director of Space Studies Observatory at the University of North Dakota, who has not participated in the study, underlines however that 'if an asteroid is composed of solid iron, it will be impossible to slow it down.' And at such a distance, it’s impossible to know in advance the composition to pull only certain objects.
Even if Minghu Tan’s study does not come to fruition, space drilling is definitely part of our near future. There are few, the most serious being The Institute of Geological Studies in the United States which is in the process of mapping out space with the intention of space drilling of asteroids…maybe even the moon.