August 13, 2013
Harnessing Asteroids: 12 Asteroids Meet “Easily Retrievable Object” Criteria
Enid Burns for redOrbit.com - Your Universe Online
While disaster movies are made about the looming threat of asteroids colliding with the earth, scientists are studying the space rocks for their mineral potential. Now scientists at the University of Strathclyde in the UK have identified a new category of asteroid they deem easy to capture.Scientist Daniel Garcia Yarnoz and a few colleagues at the University of Strathclyde have studied a database of over 9,000 near-Earth objects, and identified the ones that can be maneuvered into accessible orbit by changing their velocity by less than 500 meters per second, MIT's Technology Review reports.
Accessible orbit is defined by these scientists as orbit around the L1 or L2 Lagrangian point. This is where the gravitational force of the Sun and Earth are in balance, which is approximately a million kilometers from the earth.
The new class of asteroid is categorized as "Easily Retrievable Objects" or ERO, and so far 12 asteroids meet these criteria.
Yarnoz and his team have estimated one asteroid has a diameter of between two and seven meters. The asteroid is known as 2006 RH120. This asteroid can be directed into orbit around L2 by changing velocity by 58 meters per second. But this change in orbit will not be able to be achieved until February 1, 2021, and it will take five years to reach its destination.
There are a few more reasons than just avoiding collision with earth for scientists to want to control asteroids. Many believe the large rocks can be mined for minerals. Space exploration company Planetary Resources is among the companies looking to asteroids for the next mining location, according to Gizmodo and NASA reports.
The cost might make it prohibitive to bring materials mined from asteroids back to earth. However, some scientists believe asteroids can be mined to further space exploration. That is, asteroids can provide fuel and even raw materials to build and power rockets deeper into space. Many believe asteroids will be the next gold rush, with companies racing to claim space objects to capture the materials they're made of.
The feasibility of mining asteroids has been long-debated. According to The Verge, "The main limiting factor the scientists found was the energy it would take to transfer the asteroids from their current orbits between the Earth and the Sun, or the Earth and the moon. As long as an asteroid could be moved at below as speed of 500 meters-per-second, the transfer should be doable, according to the researchers. These 12 asteroids fit the bill, so whenever NASA decides to select its target, it would be well advised to consider these candidates. However, researchers also note that whenever NASA or anyone else attempts this mission, they need to be very careful: 'Regarding the safety of such a project, there could be a justified concern regarding the possibility of an uncontrolled re-entry of a temporary captured asteroid into Earth atmosphere'."