Despite that I decided to revisit Mr. O’Neill since he writes about stuff that will impact all of us in the future. Maybe even sooner than we think. How can a one dimensional universe effect you? Well, we know that we can’t travel faster than light in our three dimensions, but if (as reported last week) there are 11 current dimensions, then that’s where we’ll have to visit if we want to become galactic tourists.
But, today, I’m going to focus on something a little closer to home and doesn’t require any math. Not even arithmetic. As many of you already know, scientists and laypersons alike have been using some very high tech gear to search the cosmos for radio signals. The project, called SETI (Search for Extraterrestrial Intelligence), has made some interesting discoveries. But, as Ray Villard reports on Ian’s page today, scientists have come up with another way to see if life exists outside our solar system.
Instead of looking for a radio signal moving at the speed of light while we are on a planet that is rotating at speeds over 1,000 MPH while circling the sun at 67,000 MPH, they’ve decided to look for evidence of technological debris from mining.
Rather than looking for aliens who use interstellar radio signals to say “hi,” an alternative search strategy is simply to spy on any mega-engineering projects that an advanced civilization might be undertaking. Veteran SETI astronomer Jill Tarter calls this strategy “SETT” — the Search for Extraterrestrial Technology.
A new science paper by Duncan Forgan at the University of Edinburgh in Scotland and Martin Elvis at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., suggests we look for evidence of a very ambitious macro-engineering project: the wholesale mining of an asteroid belt. The asteroid material may be mined to build space colonies, solar power satellites or maybe even an entire “ringworld,” as imagined by sci-fi writer Larry Niven.
What’s more, precious metals are in high demand for technologies such as computers, high-speed networks and mobile phones. So-called “green technologies” of the future, such as hydrogen fuel cells, will also place a demand on rare resources.
The unconsolidated debris from the birth of planets, asteroids provide a smorgasbord of elements and minerals for harvesting. Meteorite samples suggest that large quantities of gold, platinum, iron, nickel, magnesium and silicon, among other elements, are abundant on asteroids.
Space Freight Cars
We have already found asteroid belts around other stars. In fact, the star Epsilon Eridani has three nested belts. NASA’s Spitzer Space Telescope has been prolific at picking out the thermal signature of extraterrestrial asteroid belts.
Any growing space faring civilization would recognize asteroids as an abundant source of raw materials. They are the coal cars in a freight train of planets.
But finding asteroid belt anomalies that would convincingly point to the handiwork of space aliens would be very tricky. First, we would need to presume that the civilization was so advanced that it built — at huge expense — the transportation infrastructure for getting back and forth to the asteroid belt. Advanced robots would have done all the heavy lifting for mining and transporting asteroid material to space-based factories.
Forensic clues could come from identifying a chemical disequilibrium in the belt caused by the extraction of specific minerals and elements. Second, the system might look odd due to the disassembly of its larger asteroids. Finally, large quantities of dust from mining might give the belt an unusual temperature distribution.
The researchers predict that persistent mining over long periods will artificially reduce the number of larger asteroids in the system debris. All that would be left would be pebble-sized and smaller dusty debris. No space telescope envisioned could inventory the true asteroid sizes, but differences in the dust distribution might offer clues.
Natural Born Killers
In Star Wars’ The Empire Strikes Back, Darth Vader directs battle cruisers to pulverize an asteroid belt to find Han Solo and his Rebel Alliance buddies. This short-term asteroid obliteration certainly would be noticeable by a nearby civilization!
The problem is that unusual dynamical events triggered by the influence of one or more planets could evolve a disk into having more pulverized asteroids than expected. What’s more, the circumstellar cloud out of which the planetary system coagulated might have started out with unique chemical abundances markedly different from our solar system’s.
The bottom line is that asteroid systems may be as diverse and unusual as the planetary systems they inhabit. Therefore, anomalies alone could not conclusively prove the existence of alien asteroid miners. Finding an oddball-looking asteroid belt might be suggestive of astroengineering, but it certainly would not prove it.
An intense program of SETI follow-up observations might look for telecommunications leak-off signals, or there may be searches for Earth-sized planets in habitable zones near the asteroid belt. Nevertheless, SETT may be the most practical and fastest strategy for finding advanced life off Earth.
It will be two decades or more before we have large-enough space telescopes to survey nearby exoplanets and looks for biomarkers. And those data will not give a clue as to how evolved the native life is.
A space colonizing civilization, maybe no more than a millennium advanced from us, must be doing something ambitious that we can notice from light-years away with modest-sized telescopes. Maybe the evidence is already in our astronomical archives; we simply don’t recognize it, yet.
What could be proof? How about something like this? There’s a rocket engine orbiting earth that wasn’t launched from here. “Here” meaning the planet Earth, not just Chicago.
While scientists try and figure out what’s flopping around in our orbit, it’s that type of debris that will allow them to discern whether or not there’s someone else out there in our galaxy.
I know, I’m sorry, but proof is not ever going to come from anal probes or crop circles.
Listen to Bill McCormick on WBIG AM 1280, every Thursday morning around 9:10!