Did Dart Alter the Orbit?
The question of whether Dart, a small spacecraft, altered the orbit of an asteroid during its recent mission has sparked a heated debate among scientists and astronomers. Launched by NASA in 2016, Dart was designed to test the Redirect Assessment of Risk and Avoidance of Collisions by Spacecraft (DART) technique, which involves crashing a spacecraft into an asteroid to alter its orbit. The mission aimed to provide valuable data for future asteroid deflection missions, but the outcome has left many questioning whether Dart actually achieved its goal.
The DART mission targeted Dimorphos, a small asteroid orbiting the larger asteroid Didymos. On September 26, 2022, Dart successfully collided with Dimorphos at a speed of approximately 15,440 kilometers per hour. The impact was intended to change Dimorphos’s orbit around Didymos, thereby demonstrating the feasibility of the DART technique. However, the subsequent observations have not provided a definitive answer to whether Dart altered the orbit of Dimorphos.
One of the primary challenges in assessing the impact of Dart on Dimorphos’s orbit is the difficulty of measuring such a small change in a vast cosmic scale. The asteroid is only about 160 meters in diameter, and the expected change in its orbit was only a few hundred meters. This tiny change is incredibly challenging to detect from Earth, given the vast distances involved.
Despite the challenges, scientists have been analyzing data from various telescopes and spacecraft to determine whether Dart succeeded in altering Dimorphos’s orbit. The European Space Agency’s (ESA) Hera mission, which is expected to arrive at the Didymos system in 2024, will play a crucial role in this analysis. Hera is designed to study the effects of the DART impact on Dimorphos and provide a clearer picture of the mission’s success.
Initial observations from the NEAR-Shallow Space Radar (NISR) on the LRO (Lunar Reconnaissance Orbiter) and the L’Asteroid Impact Mission (AIM) have shown some changes in Dimorphos’s orbit, but the results are still inconclusive. The changes observed are within the margin of error for the instruments used, and further analysis is needed to determine whether these changes are directly related to the DART impact.
Some scientists argue that even if Dart did not alter Dimorphos’s orbit, the mission was still a success. The DART technique itself was successfully demonstrated, and valuable data were collected that will benefit future asteroid deflection missions. Others believe that the mission’s primary goal was to alter the orbit, and its failure to do so casts doubt on the effectiveness of the technique.
In conclusion, the question of whether Dart altered the orbit of Dimorphos remains unanswered. The ongoing analysis of data from various telescopes and spacecraft will eventually provide a clearer answer. Regardless of the outcome, the DART mission has already contributed significantly to our understanding of asteroid deflection techniques and the potential for protecting Earth from asteroid impacts.
