Sunday, August 21, 2011

Deflecting an earth-bound asteroid?

In this world humans are not just threatened by space rocks in common but there are bigger threats too! For longer survival of humanity, asteroids pose a much bigger threat.

65 million Years ago a six mile wide asteroid strucked off the coast of present day mexico inducing ecological changes that wiped out dinosaurs. Like-wise asteroids have brought many changes to our 'blue-planet'.

Howsoever there are so many other deep-space problems that a 'supposedly' one is not paid much attention by the public or government until it becomes 'exactly' or 'will happen' thing. Many scientists who track and study asteroids agree to it i.e. mankind will not start getting ready on its planetary defenses until and unless the threat is real. We need evidence that a asteroid is actually on a collision course with us. But the question is here - 'Will it be too late before we can act up?' Possibly it depends!

"Human beings can solve any technical problems that are put in front of us," said Daniel Durda, senior planetary scientist at the Southwest Research Institute in Boulder, Colo. and also an asteroid collisions expert. Rusty Schweickart, former NASA astronaut and founding member of the B612 Foundation, a nonprofit organization dedicated to protecting the Earth from asteroid strikes, concurred: "The geopolitical realities are daunting. The technical issues are easy by comparison."

Though we know very little about the composition of asteroids but we do know the location of where most of the large, nearby rocks actually are. Today here in earth we have many asteroid observers and trackers. One of them – NASA’s Spaceguard Survey tracks the paths of all near-Earth asteroids(NEAs) in Earth’s surroundings that are larger than 1 kilometer(0.6 miles) in diameter.
To know an asteroid’s location is step one in determining that whether the asteroid is on collision course with Earth or not. Luckily, for us none of the big asteroids pose a danger at current time. If anyone of them would have any chance of hitting earth, astronomers would figure them before a decade.

"A large impact of something 1 km across — that's a bad enough scenario that it would motivate people to take this seriously," Durda said. According to Clark Chapman, another senior scientist at the Southwest Research Institute, the international community would unite together and plan a mission to change the course of the asteroid.  Working on a deflection mission would cost a amount of $10 billion.
Although, currently, we don’t have all technology successfully developed but we know now to build nuclear devices and we have successfully sent spacecrafts to and from these rocky worlds. "A decade out, given the technology it would take to do a deflection, I think we could respond in time," Durda said.
Asteroid Ida

But some scientists think that humans need more time. They believe that it would take two missions to deflect an asteroid. The first would rendezvous with the target asteroid and figure out what it's made of and the second, which would be specially commandeered to the asteroid based on the first mission, to knock it off course. They say one decade would be minimum but that would mean sending a mission before time and this in turn leads to more risk. They say 20 years would be the minimum time.
A meteorite crater

But some say 15 years of warning would be a safe choice. Along with the time it takes to assemble a launch vehicle, launch, fly to and rendezvous with an asteroid, you also need "time enough for the deflection itself to accumulate enough change in the [asteroid] orbit for it to miss the Earth impact. Post deflection will require anywhere from say 3 to 10 years for the orbit change."
NASA along with many other organizations have started tracking this rocky worlds to figure out any possible threat. As asteroids of size 200-300 meters would tremble off whole continents, bigger ones as large as 1 kilometer would necessarily trigger out the possible things needed to wipe out humanity from this earth. Though still any probability of a 1-kilometer asteroid hitting us for now is less than 1 percent. But humans cannot stand-up for a risk if he knows that it can happen.
Fortunately, for coming 50 years we all are safe!


5 comments:

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  4. the Kepler´s Laws...2nd: line Sun-asteroid sweeps equal areas in equal times...3th: radius medium³/period² = constant

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  5. the Kepler´s Laws...2nd: line Sun-asteroid sweeps equal areas in equal times...3th: radius medium³/period² = constant

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