A IS FOR ASTEROID

A is for asteroid, a huge chunk of interplanetary debris hurtling in from the outer dark to smite us all dead on the 15th of February, 2013. There will be shattered earth, bellowing volcanoes, tsunami, nuclear winter, dogs and cats living together; the whole magilla in other words. Asteroid DA14 is coming for us all, don't fret about the car payments.

Well hang on a second, DA14 just missed us on February 22nd of 2012 six days before it was actually discovered shooting away to loop around and try again. Astronomers from the Spanish La Sagra Sky Survey outside of Grenada were able to track it, and give us a good handle on what it's orbit looks like. Which as it turns out, looks like it's out to get us.

DA14's orbit practically mirrors Earths. It forms an oval of about the same size and roughly the same distance from the Sun as is the earths, and has almost the same period, orbiting the sun in 366 days compared to earths 365. The one significant difference is that DA14's orbit is tilted about thirty degrees from the plane of our planets. The paths cross twice a year giving DA14 two shots for the price of one.

How close was the last miss, well in astronomical terms, pretty close, 1.5 million miles or about 5 times the distance from the Earth to the Moon. In terms of actual threat however, it was a comfortable margin.

What about February 15, 2013? A bit closer, a bit. DA14 is going to pass inside the Moons orbit. In fact, it will be 14 times closer to Earth than is the Moon. It will be closer to Earth than most artificial satellites. In fact, NASA likes the figure 17,000 miles close. 

Well most of NASA does. The researchers in the Near Earth Program at the Jet Propulsion Laboratory in Pasadena are going with a definite inner limit of 12, 680 miles. But it for sure is going to miss, they assert. Well, ok. But these are the same guys who sent the Hubble telescope into orbit with the wrong lens.

I'm just sayin'. 

The good news is that DA14 is not all that big. Stand at the back of the end zone at the local high school football field of your choice and look about 30 yards past the opposite end, that's about 150 yards, and roughly the diameter of DA14. It packs about one and one half times the wallop of whatever struck Tungusca, Siberia in 1908. About as much as a really big  nuke.

We can live with that. Unless, of course, we are right under it. 

But cheer up folks, DA14 has been doing this twice a year for millions of years, and hasn't got lucky yet. Better to worry about the million or so other undiscovered chunks of celestial jetsam boring in to test our reflexes, some of them the size of the national debt.

Certainly does make one appreciate the first robin of spring, does it not?




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