Earth is in constant danger of an cataclysmic event, with the existence of an estimated 1,000 near-Earth asteroids capable of causing devastation on a “continental” scale. And NASA – tasked with protecting the planet from such an apocalyptic asteroid strike – believes it has come up with an audacious solution. The US space agency is readying its Double Asteroid Redirection Test (DART), an ambitious plan slam a spacecraft into an asteroid at 13,500mph to redirect it away from Earth, the mission’s Project Scientist has exclusively revealed.
Experts estimate an impact of an object the size of the one that exploded over Chelyabinsk, Russia, in 2013 – approximately 55 feet (17 meters) in size – takes place once or twice a century.
Impacts of larger objects, such as the KT impact extinction event, are expected to be far less frequent – on the scale of centuries to millennia.This mass extinction event is believed to have wiped-out the dinosaurs by triggering a mini ice age.
However, given the current incompleteness of the Near Earth Object (NEO) catalogue, an unpredicted impact – such as the Chelyabinsk event – could occur at any time.
And it is this ever-present and unpredictable danger that has driven NASA to attempt the new planetary defence system.
Dr Nancy Chabot, the DART Coordination Lead, told express.co.uk: “The damage possible from an asteroid depends very much on the size of the asteroid.
“The DART mission is demonstrating technology that could be used in a planetary defence kinetic impactor mission, which is designed to be most effective for asteroids in the size range of roughly 100-500 meters in diameter.
“If an asteroid of this size hit the Earth, it would cause large scale regional devastation.”
The DART spacecraft will launch in 2021 and impact the smaller asteroid of the binary asteroid Didymos system in October 2022.
Currently the smaller Didymos asteroid (160m diameter) orbits the lager Didymos asteroid (780m diameter) every 11.92 hours.
Dr Chabot said: “The spacecraft will impact at 13,500mph (6 km per second), and predictions are that the 11.92-hr orbit will be changed by about 5 to 10 minutes because of the impact.
“This change in the orbit can be measured from telescopes on the Earth.
“Since DART is the first test of the kinetic impactor technology applied to a target that resembles the type of asteroid it would be used for, the results of that test will teach us a lot and make us better prepared for the next steps in any overall planetary defence approach.
“DART is a highly cost effective way to test this technology because it cleverly uses a binary asteroid system, enabling telescopes on the Earth to evaluate the effect of the impact.
“This is a very cost effective approach to do this test.”