Tuesday, August 30, 2005

The End Of The World Is Nigh...Kind Of...maybe

It's Science Day here at The Corner. I just read a story about the return of Apophis. Not the ancient Egyptian god of darkness and destruction, and not the Goa'uld poseur either. This Apophis is potentially much more dangerous. This Apophis is a 1,059 foot-wide asteroid that will pass dangerously close to Earth's center in 2029, and if it follows the right trajectory it's orbit will be deflected enough for an impact in 2036. The resulting crater would be two miles wide, and could generate tsunamis that would make last year's look like a ripple in a pond. There is, admittedly, a 1 in 8,000 chance of that happening, but orbital mechanics are extremely difficult to predict, and our understanding of gravitational forces is still kind of shaky, so it might be prudent to keep an eye on this thing. And that's exactly what former astronaut Russell Schweickart petitioned NASA chief Michael Griffin to consider. He's recommending that a transmitter be placed on Apophis so its orbit can be more closely monitored.

Why worry about this thing now? Why spend the money to launch a transmitter to something that big that's in plain view? Why do men have nipples? All excellent questions. We need to worry about this now because this asteroid is what scientists call 'really big' and if we're going to need to alter its course there are two ways to do it. One is wait till it's fairly close, then send a big rocket or explosive device to shove the thing away. The drawbacks to that plan are 1) you need a really big bang to alter the trajectory enough to avoid something as large as the Earth, and 2) most asteroids are loosely formed conglomerations of rocks, dust, and ice, and a big enough bang to move it will most likely shatter it into hundreds of smaller, but still destructive pieces. The other way is to start early, with a smaller, but more sustained deflection. Scientists predict that, done soon enough, a spacecraft similar to the one that slammed into comet Temple 1 in July would do the trick, since a deflection of even a few degrees, multiplied over the billions of miles the thing travels in just few years adds up to a huge distance. Putting a transmitter on Apophis would be relatively inexpensive, and would make it much easier to calculate the orbit with the precision necessary to truly see if we are in for a cosmic smack down. Last year I learned something surprising. Despite all the science fiction shows we've grown up with[Captain, radar just picked up an unknown object entering our system.], finding something smaller than, say a planet, in orbit is very difficult. Astronomers have to compare hundreds of nightly photos to see just which tiny dots actually move. Then you have to observe the moving stuff for a very long time to see just where, and how fast it's going. Since there aren't that many telescopes large enough for the job, it's very difficult to dedicate a single telescope to watch a single object for the requisite time. And if the object is heading toward us, then it's even harder to spot since there will be no relative movement on the photo. So planting a radio on Apophis seems to me to be a no brainer. NASA will respond to the request in a few weeks. I'll keep an ear out to see what the answer is, and let you know the outcome.

Oh, the man-nipple thing. Haven't the foggiest. Some mysteries were just never meant to be solved.

Peace out.

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