Analysis of Asteroid Orbit Change from DART Impact and New Images

Analysis of the orbit of Dimorphos, the moon of asteroid 65803 Didymos which NASA’s DART spacecraft crashed into on 2022-09-26, shows that its period decreased from 11 hours 55 minutes to 11 hours 23 minutes—a full 32 minutes. Pre-impact calculations estimated the shortening of the orbit due solely to the momentum of the crashing spacecraft would be just 72 seconds, so this result indicates the impact caused a large amount debris to be ejected which amplified the braking effect of the spacecraft alone by around a factor of 27. Although the composition of asteroids varies widely, this result is encouraging for the feasibility of diverting an asteroid found to be on a collision course with Earth. The change in orbital period corresponds to a change in the position of Dimorphos of around 640 metres per day. At that rate, an asteroid with the mass and composition of Dimorphos headed to collide with Earth could be diverted to miss the planet by a similar collision thirty years before the predicted impact. This is not an unreasonable scenario, as it is possible to predict the orbits of asteroids for centuries-long periods.

Images continue to be downlinked from the LICIACube companion spacecraft that observed the impact from nearby, and show interesting structure in the ejecta from Dimorphos which may provide clues to its composition.


Amazing in itself!! Thanks to “Our Lady of Numerical Methods!” :sunglasses:

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