In deep space, about 7 million lightyears from Earth, an asteroid with a length three times longer than the largest stadium on Earth floats around, orbiting around its mother rock. Its speed? 14,000 kilometers per second. The target? A probe 208 times smaller, traveling towards it with a speed of 22,500 kilometers per hour. The probe’s goal? To impact the asteroid, change its pre-calculated course, and save the planet from an end-all-be-all, apocalyptic, predicted misery! …Or, not? According to NASA scientists, Dimorphus, a “minor-moonlet” orbiting a larger asteroid called Didymos, poses no actual threat to us at all. In fact, the chances of impact are relatively low – less than 0.001%. So, why go through all the trouble of launching a weapon the proportional size of a toothpick, for the impact to have no effect on our planet?
Although we can never be 100% sure of what, when and if anything will hit us, having a planetary defense system doesn’t do us any harm. At 1:31 a.m. EST, on early morning Wednesday, November 21, 2021, DART, otherwise known as NASA’s Double Asteroid Redirection Test, successfully launched from the Space Launch Complex at Vandenberg Space Force Base in California. This event marked the beginning of an important milestone in history, as it was the first ever mission with the goal of redirecting another body in space, and changing its orbit. DART is an 8 meter impactor probe which, costing around $324.5 million (with an additional predicted $16.5 million to be spent on data analysis and retrieval), was launched upon on a SpaceX Falcon 9 rocket, supplied with a camera and the ability to automatically direct itself towards Dimorphos. With this, DART persevered throughout a 10 month-long journey, finally crashing against its target on September 26, 2022.
However, why Dimorphos? Why not an asteroid closer, or farther, from home? Despite its fair amount of distance from Earth to Dimorphos, the Didymos system (about 762m wide) was the best pick. NASA chose this binary system due to the fact that its target, Dimorphos, is the same size and mass of asteroids that could potentially pose a threat to Earth: about 160m wide, and 5 billion kg. Despite its similarity in mass, width and trajectory to other, possibly alarming asteroids, NASA officials reassured the public that there was no scenario in which the DART mission could have turned the asteroids into a threat. Thomas Zurbuchen, an associate administrator for the science mission directorate at NASA, stated; “There is no scenario in which one or the other body can become a threat to the Earth. It’s just not scientifically possible, just because of momentum conservation and other things” (Kivo Daily). With professional approval, and public assuredness, the mission was as safe as it was revolutionary.
Apart from the aforementioned goal of redirecting Dimorphos, a mission as expensive as DART had a few more objectives in mind. Not only was it important in terms of testing out new technologies, but DART also proved that humans can, in fact, protect themselves and Earth from potential future threats. This was key to NASA engineers while constructing the probe, as DART was built as an example for future probes to face the challenges of the coming decades. Scientists needed to accurately model the impact and its consequences in order to have the most precise data and reference points. Additionally the mission was the very first step in developing prevention methods in order to be properly prepared for future events. Technology-wise, the DART mission played a vital role in proving kinetic impact, otherwise known as the technique of intentionally crashing with an asteroid to change its course. This success means that, finally, scientists know how to protect the Earth from a potentially fatal asteroid (if one were spotted five to 10 years prior to impact). The success of the DART mission was the first demonstration of planetary defense using this method, and certainly not the last.
So, what comes next? Can scientists simply apply these techniques immediately, and quickly advance technology in this field? The answer is both yes, and no. Although the discoveries and advancements are revolutionary, the retrieval of data, images and photos after the impact will take a few years to be recovered and brought back to Earth. Due to the rare and slow nature of the construction of probes and their launches, we can expect another DART mission to happen in about four years. In the meantime, NASA scientists and astronomers will investigate and analyze the data that is currently available to them, while awaiting the information of how much the impact affected Dimorphos, as well as understanding more about its internal structure and composition, in order to fully understand what it takes to deflect an asteroid. In 2024, the European Space Agency’s (ESA) Hera mission will launch and travel to Dimorphos, where it will arrive in 2026, to collect and retrieve information, and view the aftermath of the first DART mission.
All in all, the long, difficult journey of traveling to Dimorphos and its parent asteroid will have positive effects in the long run. Not only will scientists be able to better understand the nature of asteroids, and what we can do to prevent possible threats to Earth, but DART will serve as the beginning of a historic milestone and the exemplar for all DART missions to come. What happened in space made a world of difference! DART’s effect can not only be seen in the scientific and technological realm, but also in our ordinary Google browser. If you search “Nasa DART Mission” on the search engine, a satellite will fly across the screen and crash against the images of the Mission, replicating the historic and revolutionary importance of D&D: DART vs. Dimorphos.
Watch DART’s impact here.
Bibliography:
Ortiz, Sabrina. “NASA DART Mission: Why This Spaceship Is Being Smashed Into an Asteroid Today.” ZDNET, 26 Sept. 2022, www.zdnet.com/article/nasa-dart-mission-why-this-spaceship-is-being-smashed-into-an-asteroid-today.
—. “New Images Reveal Moment of DART Asteroid Impact Captured by Italian Satellite.” CNN, 27 Sept. 2022, edition.cnn.com/2022/09/27/world/nasa-dart-liciacube-images-scn/index.html.
Greenfieldboyce, Nell. “Move Over, Bruce Willis: NASA Crashed Into an Asteroid to Test Planetary Defense.” WRVO Public Media, 26 Sept. 2022, www.wrvo.org/2022-09-26/move-over-bruce-willis-nasa-crashed-into-an-asteroid-to-test-planetary-defense.
Bardan, Roxana. “NASA’s DART Mission Hits Asteroid in First-Ever Planetary Defense Test.” NASA, 29 Sept. 2022, www.nasa.gov/press-release/nasa-s-dart-mission-hits-asteroid-in-first-ever-planetary-defense-test.
Dobrijevic, Daisy. “NASA’s DART Asteroid-smashing Mission: The Ultimate Guide.” Space.com, 27 Sept. 2022, www.space.com/dart-asteroid-mission.
Blake, Alice. “NASA’s DART Mission Completes Maneuver to Make Contact With an Asteroid.” Kivo Daily, 3 Oct. 2022, www.kivodaily.com/technology/nasas-dart-mission-completes-maneuver-to-make-contact-with-an-asteroid.