By Oyintari Ben
NASA’s strategy for the eventuality that a catastrophic asteroid threatens humanity was successful when a spacecraft slammed into an asteroid on Monday.
The estimated 11 billion pound, 520-foot long asteroid Dimorphos was struck by the 1,260-pound Double Asteroid Redirection Test (DART) spacecraft at a speed of 14,000 miles per hour, about 7 million miles from Earth.
In order to capture the mission and confirm the hit, the spacecraft launched its camera along with a shoebox-sized companion called LICIACube over a week ago.
After the collision, Nancy Chabot, planetary scientist and mission team leader at Johns Hopkins University, said: “This was a tough technology demonstration to hit a little asteroid we’ve never seen and do it in such spectacular fashion.”
The mission, which took ten months and cost $325 million to execute, signifies the culmination of DART’s journey. The asteroid orbits a larger one named Didymos, and the two were chosen because they don’t pose any threat to Earth.
Although DART hit Dimorphos successfully, NASA won’t know for weeks or even months if the mission as a whole was a success. Instead of destroying the asteroid, the CIA wanted to adjust its orbit so that it passed closer to Didymos and altered both trajectories.
Dimorphos completes an orbit around Didymos in 11 hours and 55 minutes; NASA hopes the collision shortens its orbit by 10 minutes.
However, NASA claims that altering an asteroid’s orbit by just 1% would be sufficient if a dangerous one is headed for Earth. According to NASA, there are currently close to 30,000 near-Earth objects in our solar system, which means they are 120.8 million miles away from Earth. There are over 10,000 near-Earth objects that are roughly Dimorphos’ size.
Given adequate time, planetary defence experts prefer nudging a potentially dangerous asteroid or comet out of the path rather than blowing it up and creating several bits that could fall on Earth.
Many impactors could be required for large space rocks, or even a combination of impactors and hypothetical “gravity tractors,” which would use their own gravity to drag an asteroid into a safer orbit.
According to NASA, just 40% of those asteroids have been found as of October 2021, although no asteroids of that size are predicted to strike Earth in the next 100 years. Less than 1% of the millions of more minor asteroids that could cause significant damage are recognized.