NASA Dart Mission
Science fiction VS reality
The media often portrays humanity’s struggle to save itself from catastrophic events, like meteors or comets charging towards the Earth. Fans of the movie ‘Deep Impact’, for example, might recall how a group of fictional characters attempts to deviate a comet’s trajectory by placing explosives on its surface.
Although sci-fi fiction makes these events seem likely to happen, they actually aren't. The chances of a large asteroid hitting the Earth are one in 10,000 years, and comet impacts are 100 times less common.
Still, we don’t want to take any chances, if being unprepared means risking the safety of all of humanity.
It is precisely for this purpose that in January 2016 NASA founded a Planetary Defense Coordination Office. This branch specializes in the detection and monitoring of Potentially Hazardous Objects (PHOs), which are asteroids and comets that reach a distance of 5 million miles or less from the Earth's orbit.
Crashing into an asteroid: DART
On September 26th 2022 the world watched as the most important operation in the history of planetary defense reached its pivotal moment. The Double Asteroid Redirection Test (DART) mission was an effort to see whether we can change a celestial body's trajectory by colliding into it.
The 5.9 feet wide spacecraft crashed into an asteroid called Dimorphos at the speed of 3.8 miles per second. Dimorphos was the perfect candidate for the experiment, as it orbits another asteroid called Didymos and does not pose any direct threat to Earth. This real-life planetary defense operation was most certainly not as cinematic as the one in 'Deep Impact', but it didn't fail to excite sci-fi lovers from all over the world.
Although September 26th 2022 was the mission's climax, the journey to Dimorphos took a lot longer. The mission idea was approved in June 2017 and was subjected to long procedures before the launch. DART left the Earth's surface on November 14th 2021 on board the SpaceX Falcon 9 rocket and reached its target ten months later.
Along with the many people watching the impact live on TV, astronomers all around the world got their equipment ready and measured the collision. Through this data, it was calculated that DART added 32 minutes to Dimorphos' orbit around Didymos. These results far surpassed the initial minimum requirement for mission success, which had been set at just 73 seconds.
What’s next?
Ground-based observatories all around the world are constantly measuring the size, composition and orbit of the millions of asteroids that surround our planet. Because of this, if an asteroid were to come heading for us, we’d likely be able to detect it early enough to intervene.
The progress we've made is significant and sets us on the right track. On July 20th 2023, however, NASA announced that the impact caused boulders to fly off of the asteroid. This, astronomers say, shows that there is still work to be done in studying the after-effects of these operations.
