NASA has a program called the “Near Earth Object Program” (NEO) that studies the trajectories of objects in our solar system to determine Earth impact risk probabilities.
Here are the Current Impact Risks of the known objects.
Apparently, known objects such as these are only a small fraction of the potential “problem” objects. In a vast area that literally surrounds our entire solar system is the Oort Belt, comprised of comets. The Kuiper Belt is a region past Neptune that also contains comets. (Well, they’re not really comets until they’ve gotten their tails from heading toward the sun – so actually, how about big icey dirt balls?)
Then there is the old standard asteroid belt past Mars.
The interaction of our planets graviational forces on each other and these belts – as well as transient objects within the belts themselves – can cause objects to “fall” from these belts, entering their own orbits around planets or moon or the sun, and very often crossing the paths of these objects, and colliding with them.
These represent the dark unknown for us – how a large object might just suddenly and unexpectedly collide with Earth – and we may or may not detect it before it nears – not that it would matter much if the size were great at all.
Nevertheless, the NASA effort is pretty cool – there’s even a section where you can watch the orbits of some of these NEOs – how they cross the orbital planes of the planets.
Today at 06:35:28 PST the asteroid 4179 Toutatis passes very near our planet, it’s closest distance being 963,000 miles – about 4 times the distance of the Moon to Earth. 4179 Toutatis is about 3 miles long.
If you’re interested, 4179 Toutatis rotates strangely – on two axis. NASA has produced an animated model of its rotation.
Obviously, the impact of an object this size on our planet would be catestrophic. Oddly enough, asteroids are not all built the same, though. Some are far more or less dense than others, and comprise of different component ratios. This is one of the main reasons NASA has been sending probes to these objects lately – to better understand them.
The funniest probe, to me, was NEAR Shoemaker. Sent to the Asteroid Eros. We had never really travelled out to an asteroid before, and orbited it. They’re so tiny in relation to the distances – and not at all shaped like a nice ball you can orbit – so it was challenging. But they did it, and even landed the probe on the surface when it was done – which it was not designed to do. It survived it, though… And there it’s riding along, whirling through our little neighborhood, to this day.
So, can we actually do anything to stop a collision? Well, it depends. Right now, we’re not even likely to detect an object in time to even attempt anything. The first reaction was to send nuclear warheads to blow it up. But these warheads would need to be quite huge to make much difference, and presents an even greater risk just for us to have in our arsenal. After all, we still seem to be pretty stupid on most accounts, when it comes to being good to each other.
So the ideas now have shifted to detonating a nuclear blast just near enough and powerful enough, and far enough out from Earth, near the asteroid, to alter its trajectory so that it misses its destined Earth impact.
Who knows? In the meantime, Fall is arriving. Micah made small talk. And I just made the best batch of fudge I’ve ever made yet, tonight.
So think of old 4179 Toutatis today, zooming on by for another pass later on. And all the many other things that live above, and around us, that we cannot see or know. Then enjoy that breakfast or lunch. And even the little small talk…