Using Trojans

The phrase “Trojan asteroid” meant, a century ago, an asteroid in a gravitationally stable point either 60 degrees ahead or or behind Jupiter, but in its same orbit. These are “low spots” gravitationally, and tend to collect debris over time.

The equivalent orbital points in the Earth-Moon system are called Lagrange points, and the points 60 degrees in front of and behind the Moon, called Lagrange Points 4 and 5 or L4 and L5, are ideal places to build space stations.

Rather than being single points, they are oblong, curved areas spread out somewhat along the orbits because of other bodies’ gravitational disturbance. This is particularly true of Jupiter’s orbit, where there is room for lots of asteroid material:

The green dots are collectively the Trojan asteroids. But a naming convention early on had the ones in front of Jupiter in its orbit given the names of famous Trojans, and the ones behind, the names of famous Greeks. (This convention didn’t quite solidify until there had been a couple of wrongly named ones in each camp. Perhaps these Greeks in the Trojans’ territory and Trojans in the Greeks’ territory were the first “spy satellites.”)

There may be as many as a million asteroids a kilometer or more in diameter in these two groups, though evidence now suggests that the number is more likely in the thousands or tens of thousands.

They are rich potential sources of rare elements. A small one could provide the platinum for a century’s worth of catalytic converters, and supply enormous amounts of rare earth elements that we are currently getting from China, at whatever quotas they set. One problem is that Jupiter’s orbit is a long way away.

Earth, however, has the same sort of arrangement. With its smaller gravity, it doesn’t capture as much, but there are still bodies that have caused the term “Trojan asteroid” to be used more generically.

Earth’s Trojans are relatively easy to get to — easier than landing on the Moon, in fact. And we know of a number of them that are ideal candidates for retrieval and mining. A “slow boat” to get there, and a slow push to gradually adjust the orbit, would result in a nice chunk of real estate parked near the Earth and offering a near-endless supply of precious materials. Drop it down into the atmosphere to land in shallow water for retrieval, and you’ve got the makings of a profitable business.

In the meantime, you’re fetching the next one out. Here’s an ideal candidate, with a nice graphic of the orbit wandering around the Trojan point.

===|==============/ Keith DeHavelle

  • One day, in a galexy and solar system very much like our own, on a planet very, very much like our own, someone will say: “the second planet needs a much shorter day and a moon, and it wouldn’t be too much harder to bulk up number four and give it a bigger moon too”. One day. The possibilities are enormous. It might also help reduce the surplus population by spreading it around a little? Makes you want to believe in reincarnation just to be a part of it;-)

  • Wow, what a fun idea, I have to wonder though, how much material would be lost and dispersed in the atmosphere if we were to drop one into the ocean for ease in dismantling it? Oh, and on a side note, what if we used it to build space ships in space? Could we actually forge alloys in space using ample solar power to fire electric furnaces and injection techniques to build trusses, beams, and sheets? Just a thought. I find it exciting that there finally are private space launch vehicles being developed and it seems like finding ways to use space bound materials would really open up the future.