NASA’s DART mission, which successfully collided with the Dimorphos asteroid last year, has led to a series of unexpected outcomes. The most recent discovery is the lengthening of the asteroid’s orbital period around its larger partner, Didymos.
The DART (Double Asteroid Redirection Test) mission involved intentionally impacting the Dimorphos asteroid with a fridge-sized spacecraft traveling at speeds of up to 14,000 miles per hour. The goal was to alter the asteroid’s orbital path around Didymos. The mission was a resounding success, as it shifted Dimorphos’s position by tens of meters and changed its orbital period by over half an hour.
One unexpected outcome of the mission was the powerful recoil effect observed during the impact. Dimorphos, believed to be made up of loosely connected rocks, pebbles, and dust, released a significant amount of material into space upon impact. This enhanced the force of the impact, making the deflection much more efficient than anticipated.
Another unexpected finding was the creation of a “boulder cloud” around Dimorphos. The impact threw approximately two million pounds of dusty rock into space, resulting in nearly 40 boulders in close proximity to the asteroid. While these boulders do not pose a threat to Earth, they highlight the potential danger of deflecting a hazardous asteroid.
The most recent discovery was presented at an American Astronomical Society meeting. Researchers found that Dimorphos’s orbital period had actually extended by approximately one minute, contrary to the expected shortening of the period. The cause of this lengthening is still unknown, and further observations and studies are needed to understand the phenomenon.
One theory suggests that the rapidly forming and evolving debris cloud around Dimorphos could be impacting its trajectory. However, the researchers are not entirely convinced by this explanation. Known mechanisms, such as the YORP effect and mutual tides, cannot explain the observed differences in the orbital period.
Further insights and observations from scientists, including the upcoming Hera mission from the European Space Agency (ESA), will contribute to understanding the results of the DART experiment. The Hera probe, set to launch in October 2024, will closely study the Didymos-Dimorphos binary system and provide more information about the unexpected outcomes of the mission.
The DART mission has demonstrated the potential of using kinetic impactors to redirect dangerous asteroids. However, there is still much more to learn about these celestial bodies and the effects of such missions. With continued research and exploration, scientists hope to improve our understanding of asteroids and develop strategies to protect Earth from potential threats.