By Charles Carter, 27/09/22
Innovators at NASA have smashed their DART spacecraft into asteroid moonlet Dimorphos in the world’s first planetary defense test of asteroid deflection.
They aim to prove that humanity can change the course of future asteroids that are headed for earth to avoid disaster, by intentionally hitting them with spacecraft.
The team will be studying the trajectory of Dimorphos over the coming weeks to confirm the redirection, which they expect to be a shortening of its orbit around larger asteroid Didymos by around 1 percent.
How does it work?
Just like when snooker balls collide and change direction, the DART impact exerts a force on the asteroid which changes its direction.
The Double Asteroid Redirection Test (DART) mission spacecraft was launched on a Falcon 9 SpaceX rocket 10-months ago.
Its onboard instrument, the Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO), detected the asteroid two months before impact, from approximately 20 million miles away and refined its trajectory.
Fifteen days before the collision, DART released the 14kg 30cm Light Italian CubeSat for Imaging of Asteroids (LICIACube) to record footage of the collision from a third-person perspective.
The 570-kilogram box-shaped DART spacecraft successfully made impact at roughly 14,000 miles per hour, with its DRACO camera sending images to a livestreamed NASA event.
Images from LICIACube will be transmitted one by one over the coming weeks.
What are the potential benefits?
Earth’s history is littered with asteroid impacts that have had devastating consequences, the biggest being the extinction of the dinosaurs.
A 6.2-mile diameter asteroid hit the Yuctan peninsular, Mexico over 66 million years ago creating the 110-mile wide Chicxulub crater and dust cloud semi-blocking out the sun. Plant growth was severely affected and the knock-on effects caused the earth’s living ecosystem to collapse.
Avoiding a similar fate for humans is existential and DART is a step on the path to achieving this.
Many different asteroid impact avoidance methods have been proposed but all generally fall into two categories: deflection or fragmentation.
Non-nuclear kinetic impactors like DART are most likely the simplest solution, at least for dealing with smaller asteroids, which helps to keep the costs and risks low.
But with the likes of the late Stephen Hawking believing that asteroid impact is the greatest threat to humanity, perhaps a range of methods should be tested and fast!
Questions for you. Comment below
- First thought that comes into your head?
- Pros and cons according to you?
- Other applications of this approach?
- What could this be combined with?
Links
https://www.nasa.gov/planetarydefense/dart/dart-news
https://www.nhm.ac.uk/discover/how-an-asteroid-caused-extinction-of-dinosaurs.html