Rocket Science for the Rest of Us

The lesson didn't really talk much about the Kuiper Belt Objects, so I found this video:

Is anyone else reading the lessons along with me?  I'd love to get some discussions going.  This lesson is a good one, since we're so interested in asteroids not just because someday one might hit the earth (We've had some close calls, astronomically speaking.) but also because if we can find a way to capture and mine these asteroids, especially, we will go a long way to developing an infrastructure for colonizing the solar system.  (BTW, the lesson does not say what albedo is--it's simply how much light is reflected off a surface. as a comparison, the moon's albedo is .12.)

I think that if I write a story about asteroid miners, I will have to consider the Jovian LaGrange points.  LaGrange points are nice "balance points," between two large bodies.  Something in the LaGrange point will stay in that spot without having to expend extra energy.  It's commonly considered a good spot for space stations; in this case, a nice big mining colony sounds good.

This lesson had some good basic information, but it served to remind me about how much more I need to know about asteroids should I decide to write more about them.

Do you want to learn more about asteroid mining and what we're looking at now?  If so, I'll do some research; several universities are exploring this, of course, but I'm not sure if any companies are.  I think we first need to make getting to space cheaper.

Looks like we may not be in as much danger as we thought.

NEOWISE observations indicate that there are at least 40 percent fewer near-Earth asteroids in total that are larger than 330 feet, or 100 meters. Our solar system's four inner planets are shown in green, and our sun is in the center. Each red dot represents one asteroid. Object sizes are not to scale. Image credit: NASA/JPL-Caltech

In 1998, Congress asked NASA to map the skies and determine just how many asteroids that could wreck havoc--from Armageddon to "Downtown is now a crater--news at 11."  This means asteroids roughly 330 meters in size and spanning as far as the asteroid belt.  the result id good news for the Earth...and not-so good news for Hollywood or Armageddon alarmists.  The estimate of asteroids that could destroy our home has been cut significantly:  from 35,000 to about 19,500.

The main reason:  we can judge sizes better in infrared, which is what NASA is using in its Wide-field Infrared Survey Explorer.  Using infrafre rather than visible light, we can get a better idea of the size of an object because it doesn't depend on how well the object reflects light.  A material's ability to reflect light is it's albedo.  As you can see from this image, a small object with a high albedo looks as bright as a big object with a low albedo.  In infrared, however, the size is more apparent.
So the number of wreck-your-world asteroids is cut.  Does that help us?  Perhaps, in that we can more easily track them.  Of the large asteroids, 981 have been found, and we're tracking 911 already, for example.

Of course, the real question is, should we see one heading our way, what can we do?  At least we know the chances of that happening are smaller.  None of the large planet-killers should be heading our way for a few centuries, according to NASA, so we have some breathing time.


Full article here: http://www.nasa.gov/mission_pages/WISE/news/wise20110929.html