When the Dart mission launches on November 24, scientists will be on their toes to attempt a first of its kind event in deep space – crashing a spacecraft purposely in an asteroid. As the spacecraft hits the celestial object, scientists are hoping it will change the orbit of the asteroid and demonstrate a unique planetary defence system.
The mission will lay the foundation stone for a defence system to safeguard the planet from any potential asteroid impact in the future. “The mission is a demonstration of capability to respond to a potential asteroid impact threat, should one ever be discovered,” Nasa said.
The spacecraft will be launched on November 24 on a SpaceX Falcon 9 rocket from Vandenberg Space Force Base in California.
WHAT IS THE DART MISSION?
The Double Asteroid Redirection Test or Dart mission, is the demonstration of kinetic impactor technology, hitting an asteroid to adjust its speed and path. DART will be the first-ever space mission to demonstrate asteroid deflection by a kinetic impactor.
The spacecraft will travel through the vastness of the universe for nearly a year before arriving at its destination, the binary asteroid system Didymos. The spacecraft will hit the asteroid while travelling at a speed of roughly 24,000 kilometres per hour.
The mission has been built and is operated by the Johns Hopkins Applied Physics Laboratory (APL), under the direction of NASA’s Planetary Defense Coordination Office (PDCO).
WHY ARE WE CRASHING THE SPACECRAFT?
Scientists speculate that the impact will change the orbit of the asteroid within the Didymos binary system. This will demonstrate a new way to deflect potentially dangerous asteroids heading towards Earth in future. After impact, the investigation team will measure how much the asteroid is deflected using telescopes on Earth.
The data from the crash can help scientists create mini-impacts in a lab and build sophisticated computer models based on those results.
“Carrying out a real-world test on an asteroid with mostly unknown physical properties is a necessary next step to evaluate current models and advance them further to address potentially hazardous asteroids in the future. DART’s impact will both enhance and validate scientific computational models that are critical to predicting the effectiveness of a kinetic impactor,” the mission brief states.
WHAT IS THE BINARY ASTEROID SYSTEM THAT NASA IS TARGETTING?
The Didymos binary asteroid system was chosen since it has no chance of heading towards Earth in future and could be an untouched test bed for new technology.
The system is composed of two asteroids: the larger asteroid Didymos (diameter: 780 meters, 0.48 miles), and the smaller moonlet asteroid, Dimorphos (diameter: 160 meters, 525 feet), which orbits the larger asteroid.
The near-Earth asteroid was originally discovered in 1996 by Joe Montani of the Spacewatch Project at the University of Arizona. The Didymos system is an eclipsing binary as viewed from Earth, meaning that Dimorphos passes in front of and behind Didymos as it orbits the larger asteroid as seen from Earth.
The intercept is scheduled for late September 2022, when the Didymos system is within 11 million kilometres of Earth, enabling observations by ground-based telescopes and planetary radars.
Nasa said, “The DART demonstration has been carefully designed. The impulse of energy that DART delivers to the Didymos binary asteroid system is low and cannot disrupt the asteroid, and Didymos’ orbit does not intersect Earth’s at any point in current predictions.”