AstronomyScienceWar, Violence & Terrorism

Asteroids and the Human Near Future in Space

(Image: ESA)

If news reports from earlier this year are to be believed, aster­oids are high on the list of celes­tial bod­ies to be explored - and manip­u­lated. On May 13th, The Tele­graph revealed that Brit­ish astro­naut Tim Peake was going to be trained by NASA for an aster­oid sur­face mis­sion. Only weeks earlier, on April 24th, the Amer­ican com­pany Plan­et­ary Resources announced its plans to invest in aster­oid min­ing tech­no­logy. In the back­ground the impress­ive explor­a­tion data from NAS­A’s Dawn mis­sion to the aster­oid belt trickles in, mainly con­cern­ing pro­to­plan­ets Vesta and Ceres.

It’s clear that at least some of the pro­fes­sional and pub­lic focus con­cern­ing space explor­a­tion has shif­ted away from Mars and the Moon towards the (mostly) smal­ler objects in the solar sys­tem. Space between Mars and Jupiter, for example, is filled - rel­at­ively speak­ing - with aster­oids, coalesced mat­ter that was pre­ven­ted by Jupiter’s grav­it­a­tional influ­ences from ever form­ing any­thing resem­bling a real planet. It’s easy to see why aster­oids would be prone to a surge in interest as well: they rep­res­ent some­thing of a hid­den side to the Solar Sys­tem in the pub­lic eye, which has for cen­tur­ies been focused mainly on the Plan­ets proper. That these lat­ter have some sort of myth­o­lo­gical status even among sec­u­lar people was evid­enced by the out­rage over Pluto’s down­grad­ing to ‘dwarf planet’ status in 2006.

As the plans presen­ted by Plan­et­ary Resources indic­ate, aster­oids - and in this case par­tic­u­larly those ~9000 that are close to Earth, rather than in the main belt -  can be con­sidered a source of untapped resources that can be har­ves­ted, par­tic­u­larly for use in space mis­sions. In terms of profit, it seems obvi­ous that the com­pany is inter­ested in rare metals such as plat­inum, as put for­ward in WIRED. One other pre­cious resource that will be less obvi­ous to most Earth-dwell­ers is water. It takes tre­mend­ous amounts of energy to launch large quant­it­ies of water from Earth into space, so if long-term manned space mis­sions could make a pit stop for water some­where in Earth orbit at a sta­tion filled with aster­oid water, that would save a lot of effort. Not to men­tion the fact that water can be used to make rocket fuel.

More deeply rooted in pub­lic con­scious­ness is per­haps the concept of the aster­oid as some­thing that can poten­tially crash into the Earth, with apo­ca­lyptic con­sequences. Indeed, this has happened before (e.g. the dino­saur extinc­tion), and it is likely to hap­pen again at some point in the future, though it is dif­fi­cult to indic­ate when - I will return to this point below. This idea has been picked up in fic­tion as well, such as in Arthur C. Clarke’s 1993 novel The Ham­mer of God, which I’ve yet to read, and more fam­ously in the 1998 films Deep Impact and Armaged­don. Why both movies about exactly the same occur­rence were made sim­ul­tan­eously is some­what of a mys­tery, but both of them firmly settled the idea of the poten­tial dangers of aster­oids in our minds.

Part of the future train­ing mis­sions con­cern­ing aster­oids may focus on devel­op­ing the tech­no­logy to deflect aster­oids from their tra­ject­or­ies, either to pre­vent them from hit­ting Earth, or instead to bring them closer to Earth for easier min­ing. Gran­ted that it will be pos­sible to do this reas­on­ably accur­ately in the future, this raises some eth­ical issues that we, man­kind, would do well to con­sider.

In his book Pale Blue Dot: A Vis­ion of the Human Future in Space, Carl Sagan devotes a chapter to aster­oids. Based on geo­lo­gical data, we may sur­mise that roughly once every mil­lion years, Earth is hit by an aster­oid large enough to cause global cata­strophe. Smal­ler impacts that can dev­ast­ate smal­ler areas of the planet like cit­ies or coun­tries hap­pen much more fre­quently, and Sagan estim­ates that the world is hit by an aster­oid with the impact force equi­val­ent to that of a large nuc­lear bomb once every few hun­dred years. Reason enough to start think­ing of ways to pre­pare for such an event, he says, and judging by what has happened since his plea has not fallen on deaf ears.

The prob­lem, how­ever, is that the tech­no­logy we can use to pro­tect the earth from aster­oids could also be used as a weapon:

The prob­lem, Steven Ostro of JPL and I have sug­ges­ted, is that if you can reli­ably deflect a threat­en­ing world­let so it does not col­lide with the Earth, you can also reli­ably deflect a harm­less world­let so it does col­lide with the Earth. […] The tech­no­logy required […] all exist today. (p. 255-257)

Sagan is on to some­thing here, apply­ing his trade­mark skep­ti­cism to aster­oid-deflec­tion tech­no­logy, and won­der­ing if this tech­no­logy will be safe in our hands. Can we be sure that this tech­no­logy won’t be used by some nation or other group (a cor­por­a­tion?) to inflict tar­geted dev­ast­a­tion on some other? It is not unthink­able that this tech­no­logy could spark a new Cold War, or worse:

If we develop and deploy this tech­no­logy, it may do us in. If we don’t, some aster­oid or comet may do us in. The res­ol­u­tion of the dilemma hinges, I think, on the fact that the likely times­cales of the two dangers are very dif­fer­ent - short for the former, long for the lat­ter.
[…] Since the danger of mis­us­ing deflec­tion tech­no­logy seems so much greater than the danger of immin­ent impact, we can afford to wait, take pre­cau­tions, rebuild polit­ical insti­tu­tions - for dec­ades cer­tainly, prob­ably cen­tur­ies. If we play our cards right and are not unlucky, we can pace what we do up there by what pro­gress we’re mak­ing down here. The two are in any case deeply con­nec­ted. (p. 262-264)

Whether one agrees with Sagan’s assess­ment of the human pro­cliv­ity to viol­ence or not is a mat­ter of debate. Per­son­ally, I’m inclined to agree, and regard­less, it might not be a risk we want to take. Surely it could­n’t hurt to take his advice into account, and make sure that there are polit­ical insti­tu­tions and treat­ies in place that ensure the non-viol­ent use of deflec­tion tech­no­logy and the mon­it­or­ing of this use, before we start mak­ing ser­i­ous work of it. It would be a damn shame if man­kind proves its crit­ics right be des­troy­ing itself before some­thing else gets the chance to do so.

Finally, I wish to briefly remark on what is per­haps a less press­ing eth­ical issue, but an inter­est­ing one non­ethe­less. It con­cerns our atti­tude towards what lies bey­ond our own planet. Though I see little prac­tical harm in extract­ing resources from aster­oids, we must be mind­ful of what it means to start exploit­ing (in the rel­at­ively neut­ral sense of the word) outer space, so soon after we’ve star­ted explor­ing. Mat­ters of sus­tain­ab­il­ity come to mind, but it’s also inter­est­ing to day­dream about con­tact with other life­forms that might be out there. Once we encounter them, can we still go on exploit­ing the resources that lie within their sphere of influ­ence? This, of course, leads us to another block­buster movie, James Camer­on’s Avatar (2009), which tackles pre­cisely these moral dilem­mas. Per­haps that is one of the reas­ons why Cameron is one of the con­sult­ants on the board of Plan­et­ary Resources, Inc. - so he can keep an eye on them.


  • Carl Sagan (1994 [1997]). Pale Blue Dot: A Vis­ion of the Human Future in Space. New York: Bal­lan­tine.