The space agency says on Tuesday it plans to crash a spacecraft into a previously identified asteroid to test its ability to deflect asteroid threats, in a bid to avoid the kind of mass destruction that destroyed the dinosaurs, but which today is feared more than ever, with the risk of an impact within a century.
Maneuvering asteroids
The space agency said it was flying the space rock (comprising an object of around 140ft in diameter) down to its detection orbit about 2.8million miles (4.1 million km) from Earth so it could be smashed into. These orbits mean a solar wind is also not blocking their radiation, meaning they can still heat up and cause catastrophic damage to the Earth. The plane will be launched from Cape Canaveral, Florida on 4 March, and the crash will happen between 10am and 11am ET, according to Nasa.
The asteroid is designated the 2014 JO25, which is said to be flying towards Earth on a trajectory to impact in the early 2070s, and could be the next object threatening human life. It will make it into the detection orbit around April 2026, then the agency will shoot a kinetic impactor (a material detonated at a speed) at the asteroid.
Will we succeed?
Nasa scientists believe an impact is not necessarily imminent, given how long it will take the asteroid to pass by. And if it does hit the ground, they believe the impact will provide further evidence of the threat posed by future asteroids.
Why is Nasa doing this?
The Space Act Agreement signed by Nasa and Italian scientists on 12 December 2017 put the hazard posed by asteroids in a global context and illustrates to scientists an approach that could be used to safely deflect future asteroids. The idea is not to destroy the asteroid, but to send a craft that would hit it, travelling at 40,000 miles per hour. The spacecraft would open a small hole in the asteroid.
This crash of a craft is said to be the first high-speed collision in a mission designed to deflect an asteroid in the 22 years that Nasa has been conducting its asteroid risk-reduction mission.
Technicians with NASA’s Dawn spacecraft at an assembly facility in March 2012. Dawn orbited and orbited Ceres and later carried out its first close observations of Vesta. Photograph: Tristan Clement/NASA/JPL-Caltech/MSSS
Why now?
It’s an issue that the public knows about, even if politicians and officials don’t, according to Michael West, spokesman for Nasa. “It’s very clear to everybody,” West said. “People want to know what we’re doing to stop an asteroid from hitting the Earth. You can’t stop an asteroid from colliding with the Earth.”
So why the crash?
Short answer is that, what is being called a ‘mini-impactor’ is a Nasa craft that hits an asteroid, increasing the friction in a couple of critical areas. Even in this slightly larger version of the impactor, the pressure is expected to cause the asteroid to be pushed out of the way.
This mission would extend the risk of a destructive event, but the science involved – trying to demonstrate how to alter an asteroid – is worth doing.
Why is the public worried?
Guns
A mass event could be the stuff of Hollywood movies, and what passes for community discourse in the US is of course political debate, with much discussion around what comes after Donald Trump’s decision last year to pull the US out of the Paris climate agreement.
This also comes after a report published on 6 December by the American Association for the Advancement of Science, which highlighted an increase in the number of potential asteroids and other dangerous space objects getting closer to Earth. They concluded that within 100 years there could be an object the size of the asteroid that hit Russia in 2013, which injured more than 1,000 people and caused widespread damage. Scientists believe the arrival of larger asteroids that can penetrate Earth’s atmosphere could lead to impact millions of years earlier.