[meteorite-list] Astronomers Identify 12 Candidates for Asteroid Mining

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 15 Aug 2013 12:50:45 -0700 (PDT)
Message-ID: <201308151950.r7FJojal016006_at_zagami.jpl.nasa.gov>

http://www.extremetech.com/extreme/163749-astronomers-identify-12-asteroids-we-could-easily-mine-for-valuable-resources

Astronomers identify 12 asteroids we could easily mine for valuable resources
By Ryan Whitwam
Extreme Tech
August 12, 2013

Science fiction authors and futurists have been musing on the possibility
of mining asteroids for decades, but last year a company called Planetary
Resources declared its intention to actually do it. That got people thinking
about whether or not humanity has really reached the point where asteroid
mining could become a reality. A group of astronomers at the University
of Strathclyde in the UK have replied with an emphatic, "yes.' They have
identified 12 near-Earth asteroids that could be easily retrieved and
mined with current rocket technology.

It's believed that asteroids could contain large deposits of industrial
and precious metals. An unremarkable one-kilometer asteroid could contain
upwards of two billion tons of iron-nickel ore, which is three times the
global yield on Earth. Then there is the likely presence of gold, platinum,
and other rare substances. Planetary Resources claims a 30-meter object
of the right composition could contain $25 to $50 billion in platinum.

These numbers spurred the University of Strathclyde team, led by Garcia
Yarnoz, to pour over the astronomical data on near-Earth objects to see
if any of them could actually be snared. To their surprise, they found
12 small asteroids that pass close enough to Earth that they could be
corralled into the L1 or L2 Lagrangian points for mining operations. The
researchers dubbed these asteroids Easily Retrievable Objects (EROs).

Lagrangian points are regions of space where the gravity of the Earth
and another celestial body balance out. If you place something in a Lagrangian
point, it stays put. That's exactly what you want if you're going to start
drilling into an asteroid. The L1 and L2 Lagrangian points are where the
gravity of Earth and the sun are at a draw. They are about 1 million miles
from Earth, or about four times the distance to the moon.

The 12 candidate asteroids are in orbits that take them near the L1 or
L2 Lagrangian points, so they would need only a small push to get them
to the right spot. Yarnoz and his team estimate that changing the velocity
of these objects by less than 500 meters per second would be sufficient
- some would take substantially less effort. One ERO called 2006 RH120
could be captured by changing its velocity by only 58 meters per second.
This could be completed as early as 2026.

One of the important criteria in filtering the database of 9,000 near-Earth
objects down to the 12 mineable asteroids was size - we simply don't have
the technology to safely nudge a large asteroid into a Lagrangian point.
There will be no mega-sized mining platforms spanning a one-kilometer
asteroid in the near future. Most of the EROs identified by the study
are in the two to 20 meter range, but that's still large enough to contain
substantial resources.

These 12 objects are probably a small fraction of EROs floating around
near Earth. We know where many more of the big space rocks are because
they're much easier to see, but there might be a wealth of resource-rich
small asteroids near the Lagrangian points ripe for the picking.

Research paper: arXiv:1304.5082 - "Easily Retrievable Objects among the
NEO Population" (Paywall)
http://arxiv.org/abs/1304.5082
Received on Thu 15 Aug 2013 03:50:45 PM PDT