A team of MIT scientists has developed a computer program that helps people decide how best to deal with the end of the world, as long as it happens in the form of a catastrophic asteroid collision.
Experts say that two or three new asteroids, sometimes called “Near Earth Objects,” are discovered every night.
It is inevitable that one of these asteroids will eventually end up in a collision course with the earth.
A team of scientists from MIT have developed a new computer program to simulate all possible approaches to dealing with an asteroid on Earth’s orbit.
“People have mainly considered strategies for last-minute deflection when the asteroid has already gone through a keyhole and is on its way to a collision with the earth,” Sung Wook Paek, of the Aviation and Astronautics Department of MIT, told MIT News.
“I am interested in preventing keyhole passage well before the impact on the earth. It is like a preventive attack, with less clutter. “
The Paek team designed the program to evaluate the mass, momentum, trajectory and time before the expected impact to help people make high decisions to prevent global disasters.
The core of the decision comes down to something called a gravitational keyhole, a point in space where an orbit of an asteroid would pass it into the gravitational field of the earth and gradually make its way to the surface of the planet.
If asteroids can be detected before this point is reached, they can be diverted with small course changes – sometimes just a few centimeters per second.
But with the stakes so high and the windows for success so narrow, there is little room for human error or hesitation.
The program aims to prevent asteroids from entering the “gravitational keyhole”, a point in space where they enter the Earth’s gravitational field, making a potentially catastrophic collision inevitable
“Does it matter whether the chance of a mission’s success is 99.9 percent or only 90 percent?” Said MIT co-author Olivier de Weck.
“When it comes to deflecting a potential planet killer, bet it does.”
“That’s why we have to be smarter when designing missions based on the degree of uncertainty.”
“Nobody looked at the problem this way.”
The most effective method, according to a 2007 NASA recommendation to Congress, is to send a nuclear missile to explode on the asteroid surface.
This option would also leave a significant amount of nuclear waste in orbit around the planet, which would eventually re-enter the atmosphere and cause a number of complications, making it the most controversial and least likely.
A better option would be to use a “kinetic collision body,” such as a rocket or a large projectile, to knock the asteroid off course, similar to hitting a billiard ball with a guideline.
IS EARTH SUITABLE FOR A BIG ASTEROID IMPACT?
Researchers have discovered most of the asteroids that are about a kilometer long, but are now hunting for those of about 140 meters – because they can cause catastrophic damage.
Although no one knows when the next major impact will occur, scientists are under pressure to predict – and intercept – its arrival.
Artist’s impression shown
“Sooner or later we will have … a small or large impact,” said Rolf Densing, head of the European Space Operations Center (ESOC) in Darmstadt
It may not happen in our lives, he said, but “the risk of ever being hit by a devastating event is very high.”
“For now there is little we can do.”
This option has a considerable amount of uncertainty, because it depends on the projectile that travels at exactly the right trajectory at the right time and delivers the right amount of force to have an effect on the asteroid.
To test their program, the Paek team performed a number of simulations using two well-known NEOs, Apophis and Bennu, while the coordinates of their gravity keyholes were changed in the simulation to see how different times affected the outcomes.
The computer came with different approaches depending on the time remaining.
In a simulation that took five years to pass through its gravity keyhole, the simulation sent two reconnaissance vessels, one to meet the asteroid and to measure the exact dimensions and another to push it slightly.
A full-impactor ship was then launched to push it completely off course.
In another simulation, which took less than a year before the asteroid entered its keyhole, Paek said, it would be too late for scouts and sending a kinetic collision body might not reach the asteroid before it went through.