Asteroids have a high value potential for mining operations, though which asteroid is chosen depends upon mission parameters and the target’s location. For 1st Generation mining operations, we expect NEAs to be the optimum target of choice, then as we advance technologically we can explore further into the main asteroid and Kuiper belts where the immense quantity of metals, minerals, silicates, and ices contribute to a multi-faceted benefit and advancement.
Asteroids are small bodies of rock, mineral, metal, and dust while comets are bodies of ice, small rock particles and dust that orbit the sun and planets in our solar system. They are the left over debris from the time when the planets in our solar system formed, most are relatively small ranging from 5m to 1+ kilometres in radii up to 100+ kilometres, the largest asteroids (Ceres, Vesta, et al.) are classed as dwarf planets as they are very large bodies, but still too small to reach the size of a planet, there are also very few of this size body in the solar system.
The asteroid belt, more commonly known as the main asteroid belt (MAB), lays between the planets Mars and Jupiter, it is filled with a large amount of asteroids that consist mostly of rock, silicates, minerals and metals, which are what the planets of the inner solar system (Mercury, Venus, Earth and Mars) are made of and are the remnants of the material that made up these planets when they formed during the early days of our solar system.
In the outer solar system (Jupiter, Saturn, Uranus and Neptune) lays another asteroid belt, known as the Kuiper Belt. It starts just beyond the orbit of Neptune and goes outwards to 50 AU (AU stands for astronomical unit, 1 AU is the distance to the Sun from the planet Earth, roughly 93 million miles or 149,597,871 kilometres), this means that the Kuiper Belt extends outwards very far away. It is larger than the main asteroid belt as it extends further, is wider and more massive, though where the main asteroid belt has asteroids made of rock, silicates, minerals and metals, the Kuiper Belt objects consist mostly of volatiles. Volatiles are ices such as water, ammonia and methane which can be processed into rocket fuel. The Kuiper Belt also has three dwarf planets within its boundary, these are Pluto, Haumea, and Makemake.
At the extreme outer edges of our solar system lays another type of asteroid belt known as the Oort Cloud, which begins at a distance of 50,000 AU, or nearly one light year, from the Sun. Like the Kuiper Belt, it consists mainly of volatile objects such as water, ammonia and methane ices. The Oort cloud also has an inner and outer region, but is only loosely connected to our solar system as a result of its distance, which means that it is affected by gravitational pulls from the Sun, passing stars and the Milky Way galaxy itself.
Asteroids have a number of different classes, some of the most common type are the following:
C-type: asteroids are carbonaceous (carbon, which can be a dark substance as in carbon or graphite or clear as in diamond), these are the most abundant type of asteroid in the solar system, roughly 75% of all known asteroids belong to this class, though this percentage could be higher as they are very dark which makes them difficult to observe without a telescope. They are rich in silicates (various types of rock), oxides ( silicon dioxides such as sand & quartz, iron oxides such as iron ore, aluminium oxides such as aluminium ore, carbon dioxides, etc.) and sulphides (minerals & metals containing sulphur, sulphur minerals consist of iron, copper, nickel, lead, cobalt, silver, and zinc.), the minerals olivine & serpentine are commonly found in these objects as well as large percentages of ice (3-22%).
B-type: asteroids are a rare type of carbonaceous asteroid that are found mainly in the outer asteroid belt. They are volatile rich (in planetary science, volatiles are chemical elements and compounds with low boiling points, they are found in the crust & atmosphere of planets and moons. Some examples of volatiles are; nitrogen, water, carbon dioxide, ammonia, hydrogen, methane and sulphur dioxide.) remnants from the early formation period of our solar system.
P-type: asteroids are another dark type asteroid with a low albedo (how bright an object is when it reflects light. A low albedo means it does not reflect much light and is dark as a result.), they consist of organic silicates and carbon, they may also have water ice in their interiors. They are an asteroid type whose minerals may have been chemically altered by water and are mostly found in the outer edges of the asteroid belt.
S-type: asteroids are mostly a stony composition, which is why they are termed S-type, or silicate type, asteroids. Roughly 17% of the known asteroid population are made of this type asteroid, making it the 2nd most abundant class after the C-type asteroid family. S-type asteroids are moderately brighter, making them easier to observe through telescopes, and are mostly found in the inner and central regions of the main asteroid belt, they become very rare in the outer regions of the belt. They are composed primarily of iron and magnesium silicates (which can take the form of magnesium metals or stone & magnesium-silicate minerals such as olivine, humite, enstatite and more.
M-type: asteroids are a metal rich type, consisting mainly of stone and metallic iron, nickel-iron and platinum group metals (the amount of platinum group metals on just one 500 meter asteroid exceeds the entire amount on our planet). These asteroids are very bright and are found mainly in the central region of the main asteroid belt.
How do we determine which asteroids to mine?
Determining which asteroids to choose for mining missions can be a complex subject that require a comprehensive scientific analysis of its mass, composition, orbit, and structural characteristics.
We measure the magnitude variation of asteroids over a period of time, this helps us to determine its mass (the specific magnitude “brightness” of an asteroid indicates just how big or heavy it is) and it’s rotational period. We then conduct further analysis off of this data to determine its orbit, eccentricity, inclination and speed with a reliable accuracy.
We can do further observational analysis by conducting spectrophotometry, measuring its magnitude at different EM wavelengths, this provides additional detail into its composition.
We co do further analysis with spectrometry, each element, mineral, and volatile emits and absorbs light at different frequencies, so we measure asteroids with optical and infrared spectrometry which indicate what they are made of, the specific wavelength measurement of that element, mineral, or volatile details the mass which can be in an asteroid.
DarkStar Aerospace uses our optical interferometer with spectrographs, and our radio spectral-line interferometer arrays to determine these properties and calculate what value a target may have for mining purposes. We employ radar measurement to provide enhanced detail on asteroid structure and properties on targets closer to earth, such as NEAs, which will be the target choice for initial mining missions.