What is the asteroid belt?
Around half of the mass of the entire asteroid belt is comprised of the asteroids Ceres, Vesta, Pallas and Hygiea. The mean diameters of Vesta, Pallas and Hygiea are over 400km, and Ceres has a diameter of 950km. Of all the asteroids in the belt, Ceres is the only one which is categorized as a dwarf planet. The remaining bodies range all the way down to objects as small as a dust particle.
How far away is the asteroid belt?
Because the asteroid belt is between the Mars and Jupiter orbits, it is around 2.2 to 3.2 Astronomical Units (AU) from the Sun – which is approximately 329,115,316 to 478,713,186 km.
The average distance between objects is a massive 600,000 miles. To put that number into perspective, the circumference of planet Earth is only 24,901.45 miles which makes the distance between objects in the asteroid belt more than 24 times the circumference of Earth.
With the growing consumption of key elements here on Earth, along with the known reserves of those elements, there is speculation that elements such as phosphorus, antimony, zinc, tin, silver, lead, indium, gold, and copper, could be exhausted on Earth within 50–60 years.
Asteroid mining refers to the speculation that we could essential mine asteroids and other minor planets to exploit the raw materials found on them.
There are a number of materials that could be mined from asteroids, including iron, nickel, titanium for construction, water and oxygen. As an example, they could be used to sustain the lives of prospector-astronauts on site. Also, water mined from asteroids could serve space colonies and hydrogen and oxygen could be used as rocket propellant. Minerals and metals mined from asteroids might also be used to build habitats and grow food for future space colony inhabitants.
The biggest obstacle to asteroid mining is the financial feasibility of it. Space ventures are high risk, with long lead times and a lot of investment is needed. For it to be possible, affordable space flight technology will need to be developed in order to allow humans to reach the asteroids to mine. A number of potential mining projects are already under way, as companies announced their intention to mine asteroids as far back as 2012. Both Planet Resources and Deep Space Industries have begun prospecting asteroids, and NASA have their own projects in mind as well.
Facts about the asteroid belt
- The asteroid belt contains hundreds of thousands of known asteroids, while there are millions and maybe billions which are still unknown.
- While most asteroids range down in size to pebbles or even dust particles, there are 200 asteroids which are known to be larger than 100 km and there are between 0.7 to 1.7 million asteroids with a diameter of 1 km or more.
- The asteroid 1 Ceres is also a designated dwarf planet, and is the largest asteroid in the inner solar system.
- Despite the many objects in the asteroid belt, the space is so vast and the distance between objects so large (around 600,000 miles) than space craft are able to fly through the belt without colliding with any asteroids.
- Asteroids are named based on suggestions from the discoverer, and are also designated a number for identification.
- When the asteroid belt formed objects began to join together and form what are known as protoplanets. However, the gravitation pull caused by the formation of Jupiter meant that collisions of these small celestial objects became too violent and instead of fusing together, they shattered.
- As a result of these collisions it is estimated that 99.99% of the asteroid belt’s original mass was long in the first 100 million years of the solar system’s history.
- Gravitational influences can move asteroids out of the belt, often sending them into the outer solar system.
- The asteroid belt is often referred to as the “Main Belt”. This is to differentiate it from the other groups of asteroids such as the Centaurs and Lagrangians.