Friday, September 26, 2008

Earth-Crosser Asteroids: Unexamined Threat or Untapped Real Estate?

Ever since the Alvarez’s Brothers proof of an asteroid impact wiping off the dinosaurs became well known, asteroids have since been perceived as the ultimate threat to humanity and civilization. Is it now time to reexamine established assumptions?

By: Vanessa Uy

Earth-crosser asteroids have become inexplicably linked with that 1997 Veruca Salt song “earthcrosser”, which frankly to me passed muster as a depiction to what it would be like to witness first hand a seven-mile wide asteroid crashing down at 50,000 miles per hour just five miles in front of you. Something that’s not so different from what the dinosaurs living in the Yucatan Peninsula witnessed 65 million years ago. It even inspired big budget science fiction movies about what would happen if any of these space-borne high-speed “pieces of dirt” crashes into our planet’s surface at more than seven miles per second.

Earth-crosser asteroids are classified as a Near-Earth asteroid whose orbital path crosses that of the Earth’s regular orbital path. They are different – and a separate group - from Earth-Crossing Asteroids (ECA s) because ECA s are asteroids that are capable of coming very close to Earth at any point in the future and of interest to anyone manning our Spaceguard Survey Program. While Earth-Crosser asteroids, only their orbital path intersects our planet and not the asteroid physically impacting into the Earth’s surface.

Earth-crosser asteroids whose orbital semi-major axes are smaller than Earth’s are classified as Aten asteroids; the remaining ones are classified as Apollo asteroids. Of the Earth-crossing asteroids, 3753 Cruithne is of special interest because it has an orbit that has the same period as that of Earth.

Earth-crosser asteroids have very good uses as potential scientific “space station” sites in the future since their orbits take them to the inner Solar System. Thus serving as a fuel-efficient way of exploring the inner Solar System. Not to mention their potential as a source of valuable ores for the metals needed for our future space faring civilization. Or a good place for research scientists to look for organic materials that remained unchanged since the formation of the Solar System. And the most important of all, real estate for setting up colonies either for long-term studies on space colonization or just good platforms to build our future astronomical labs on.

To colonize these asteroids is probably the best way to study their motions across our Solar System and researchers on an asteroid are probably the ones who can readily obtain data. Like weather their particular asteroid they are sitting on will crash into our planet somewhere in the distant future. They can probably obtain a very exact if and when compared to their “Earthbound” counterparts.

But Earth-crosser asteroids need extensive developing to make them habitable to humans. Like the construction of pressure domes with appropriate radiation shielding from the Sun’s harmful radiation and of cosmic rays as well. Earth-crosser asteroids are very different from Earth when it comes to their surface conditions unlike the way they are portrayed in 1950’s era science fiction films. Some of them have even less surface gravity than our Moon because they are much smaller in size. But their development holds a myriad of promise for mankind.