A New Superhero for Earth - NASA’s DART Mission
In April 2022, scientists at NASA proved that they could change the trajectory of an asteroid. To do so, scientists used the Double Asteroid Redirection Test (DART) spacecraft to change the orbit of the asteroid Dimorphos. The DART spacecraft essentially slammed into the asteroid's head and pushed against the asteroid the way air is released from a balloon.
Dimorphos orbits around a larger asteroid called Didymos. Scientists predicted that the DART spacecraft would push Dimorphos closer to Didymos and cut the orbit time by ten minutes. However, scientists were shocked to learn that Dimorphos's orbit was shortened by 32 minutes through the collision. The DART mission proved to be more successful than scientists had anticipated.
An illustration of Didymos and Dimorphos near the DART Spacecraft.
Much of this success relied on the use of telescopes strategically placed around the world. These telescopes measured changes in brightness as Dimorphos orbits Didymos. Additionally, radar facilities in the United States were used to estimate the position of the two asteroids and the orbital period of Dimorphos. Through these observations, scientists could calculate that DART knocked Dimorphos 100 miles closer to Didymos.
Scientists have also found that the larger-than-expected distance Didymos traveled post-collision might be because it is a more loose collection of rocks than other asteroids. This made it easier to deflect, and scientists predict that a more dense asteroid would not deflect as much. Another concern is whether Didymos will remain in its new orbit or gravitate back to its original orbit.
Although Dimorphos is 6.5 million miles from Earth and poses no real threat to our planet, the mission was the first time scientists successfully nudged an asteroid to change its trajectory. This is critical when it comes to developing planetary defense. For example, it is widely believed that an asteroid led to the dinosaur extinction, ultimately wiping out 75% of life on Earth. Although scientists have yet to find such a large asteroid that is currently on a crash course for Earth, that is not to say that there couldn't be one in the future. Also, there are much smaller but still potentially deadly asteroids near our planet that have the ability to wipe out cities. Although these asteroids would cause damage on a much smaller scale, it is still vital for countries to develop tactics to prevent such collisions. Additionally, as of now, we only have one planet to call home. For humans to develop as a multi-planet species will take a very long time, so it is crucial to find ways to defend the one planet we do have.
Following the success of DART, scientists predict that with enough warning, they may be able to change the path of a potentially dangerous asteroid that is headed for Earth. That said, DART could also help to open up possibilities of rearranging our solar system to make it safer for space exploration. Given the many possibilities, the DART mission will push space agencies into the superhero role of protecting our only planet.
