NASA unveils new plan to deflect asteroids away from Earth
A new study conducted by scientists from NASA and the National Nuclear Security Administration outlined two possible methods for handling Near Earth Objects (NEOs) on route to collide with Earth.
The study was published in the journal Acta Astronautica and the researchers have dubbed their new plan the Hypervelocity Asteroid Mitigation Mission for Emergency Response (HAMMER).
HAMMER involves two possible options. One is a spaceship armed with a nuclear explosive that will detonate and destroy the asteroid, and the other is using the spacecraft as a kinetic impactor which will force the asteroid to change course.
The method chosen to eliminate the risk of collision with an NEO depends on several factors, according to the research team.
The researchers tested HAMMER using simulations with an NEO that was modeled after the 101955 Bennu, a well documented NEO that is the destination of NASA’s OSIRIS-REx mission.
The danger of an Earth collision with Bennu is slim, but there is a small chance it could happen in the next century.
The study’s abstract outlines the several deciding factors that will determine which option is necessary for mitigating the risk of collision. The decision would depend on the size and mass of the NEO and how much time is available before impact.
If the NEO is small enough and there’s an ample amount of time, the researchers say the kinetic impactor is the best option.
The kinetic impactor works by forcing the asteroid to change course, the gravitational field of the NEO would work with the kinetic impactor, and the NEO would be repelled and diverted away from Earth.
However, the response time and specific factors required for the kinetic impactor make a limited option.
“Whenever practical, the kinetic impactor is the preferred approach, but various factors, such as large uncertainties or short available response time, reduce the kinetic impactor’s suitability and, ultimately, eliminate its sufficiency,” the researchers wrote.
If the NEO cannot be deflected away from Earth, then the researchers suggest using a nuclear explosive device to eliminate the risk.
“The impactor is not as flexible as the nuclear option when we really want to change the speed of the body in a hurry,” David Dearborn from the Lawrence Livermore National Laboratory told BuzzFeed News.