WAYWARD ASTEROID GETS BENT
- Analysis by Ray Villard Mon Feb 14, 2011 04:26 PM ET 8 Comments | Leave a Comment
On Feb. 4, a pickup truck-sized asteroid called 2011 CQ1 was spotted zipping only 7,000 miles above the Earth's surface -- a distance slightly less than the diameter of the Earth!
The Catalina Sky Survey detected the interplanetary vagabond just few hours before closest approach to our planet.
That is the closest near miss on record, beating the previous record holder, a rock that buzzed Earth in 2004 with the dubious name, FU162.
Now, the asteroid 2011 CQ1 didn't get "bent" but its orbit sure did.
The rock's trajectory was deflected by 60 degrees as it whipped around deep inside Earth’s gravitational space warp. It was like a pinball ball bouncing off of a bumper. Short of collisions with planets, that's the biggest orbital change ever recorded by observers.
Asteroid sleuth Donald Yeomans of NASA's Jet Propulsion laboratory said the trajectory change switched the object's "tracks" from a so-called "Apollo-class" (where the object would stay farther away form Earth) to an "Aten-class" orbit where the asteroid spends almost all of its time inside the Earth's orbit.
But don't worry, a direct impact by something this size would burn up on our atmosphere, producing a spectacular fireball.
During this fleeting encounter with the space rock the Earth's orbit was ever-so minutely modified in the gravitational exchange.
According to chaos theory, this means that many millions of years from now, the Earth's orbit may have been substantially altered by this seemingly tiny event.
In recent years, computers have become powerful enough to simulate the formation and evolution of planetary systems over many billions of years. Simulations predict that gravitational encounters between objects large and small have been rearranging the solar system since it formed some 4.6 billion years ago.
In the solar system's early days, the planets Jupiter, Saturn, Uranus and Neptune migrated farther from the sun though gravitational pinball with smaller bodies. They piled the debris into the Kuiper belt of comets and icy dwarf planets.
Planetary systems reshaped by gravitational scatter look more like the norm than the exception around other stars.
A carefully programmed series of asteroid/minor planetary body close encounters with Earth could be used by our distant descendants to modify our orbit such that we nudge our planet farther from the sun as our star grows hotter and brighter in the coming billion years.
The problem with twiddling with Mother Nature is that in such an orbital modification, chaos theory -- one again -- predicts the possibility of a planetary wild card.
The orbits of other planets could be destabilized if we decided to change Earth's zip code. And, the solar system, which lives on the brink of dynamical chaos, could come unglued.
So it might be more prudent just to terraform Mars and relocate to it, rather than modifying the Earth's orbit. And, billions of years from now terraform Titan -- which will be a balmy place under the glare of a bloated red giant sun.
Asteroid 2011 CQ1 is so small it is unlikely ever to been seen coming this close to Earth again. But asteroids are like mass transit buses. If you miss one, another one will eventually come along.
Credit: NASA
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