In eight days, NASA will deliberately crash a spacecraft into an asteroid in a $330 million ($487.5 million) attempt to change the asteroid’s course.
It is the world’s first large-scale mission to test technology to defend Earth against possible asteroid collisions.
So what is DART’s mission? And should we worry about the NASA strike?
Why does NASA do this?
Space engineers want to learn how to deflect asteroids in case one is discovered on a collision course with Earth.
The DART mission, or Double Asteroid Redirection Test, will help determine whether intentionally crashing a spacecraft into an asteroid is an effective way to change its course.
Cue disaster movies like Don’t Look Up and Armageddon, although astronomers believe that such devastation is unlikely to happen in the near future.
DART is the world’s first large-scale mission to test technology to defend Earth against potential asteroid collisions.
By studying the trajectory of the asteroid after the collision, scientists believe they will better understand how collisions could be used to deflect asteroids and comets away from Earth.
DART’s target, Dimorphos, is 160 meters in diameter and orbits its parent Didymos. (Provided: NASA/Johns Hopkins APL)
What is the name of the asteroid that will hit NASA?
The mission targets Dimorphos, a small “moonlet” or asteroid that orbits a larger near-Earth asteroid called Didymos.
Near-Earth objects are asteroids and comets with orbits that place them 50 million kilometers from Earth. NASA says detecting the threat of NEOs that could cause serious damage is a primary goal.
Dimorphos is about 160 meters in diameter and is the smallest NASA has ever attempted to hit.
The largest asteroid Didymos is about 780 meters in diameter. Its name is the Greek word for “twin,” a nod to how the asteroid forms a binary system with the smaller asteroid.
DART will travel at about 6 kilometers per second when it hits Dimorphos.
When will Dart crash into the asteroid?
Monday 26th September at 19:14 US time is the scheduled time (ie 9:14am on Tuesday 27th September AEST).
It’s been a 10-month journey for the spacecraft, which, without measuring its two solar panel wings, is about the size of a small car.
Does the asteroid pose any threat?
No, the asteroid poses no threat to Earth.
“This is humanity’s first test of planetary defense,” Bobby Braun, head of space exploration at the Johns Hopkins Applied Physics Lab, said at a media briefing.
“This is all a test. It’s being done in a safe way. There’s a 0% chance that this asteroid could hit Earth, so it’s actually an ideal setup for our science team, for engineering team … and for those around the world to learn from and to improve through this mission.”
On the day of impact, the images will return to Earth via images recorded by LICIACube, a small satellite provided by the Italian Space Agency.
The briefcase-sized satellite now travels behind the spacecraft to record the collision.
At the time of impact, Didymos and Dimorphos will be 11 million kilometers from Earth.
The diameter of asteroids compared to the height of buildings and the length of the DART spacecraft to scale. (ABC: Modified from NASA/Johns Hopkins APL)
What will happen after the impact?
The plan is to fly the DART spacecraft directly into the moon by hitting it hard enough to shift its orbital track around the larger asteroid.
After the impact, scientists will use ground-based telescopes to observe whether and how much Dimophos’ orbit has changed.
As for fears of comets and a catastrophic impact with Earth, NASA says there are no known threats to our planet for at least the next 100 years.
The data collected will contribute to planetary defense strategies, especially understanding what kind of force can change the orbit of a near-Earth object that could collide with our planet if ever discovered.