On September 26, 2022, NASA intentionally crashed their DART spacecraft into the asteroid Dimorphos, with the goal of altering the trajectory of the asteroid by transferring the momentum of the spacecraft to the asteroid. The asteroid is also a satellite of the much larger asteroid, Didymos. DART impacted Dimorphos head-on in the direction opposite the asteroid’s orbital direction, causing its overall orbital velocity to decrease. The primary goal of DART was to determine the feasibility of changing the trajectory of an asteroid, with the hope that humanity will have the means to deflect potentially dangerous asteroids.
Effective Impact :
Now official: NASA has confirmed that the DART (Double Asteroid Redirection Test) space probe managed to alter – and a lot – the movement of the asteroid Dimorphos.
In the first test of a technique of planetary defense, to deflect asteroids that could come towards Earth – Dimorphos does not represent a risk – the DART probe hit the asteroid Dimorphos on the last day 26 of September, producing a plume of debris much larger than the expected.
And the result of the impact was also more bigger than expected: The impact shortened the asteroid’s orbital period around its bigger brother, Didymos, by 32 minutes.
The prediction was that a decrease of 73 seconds in the orbital period would be enough to declare the success of the technique, but the NASA simulations showed that it would be possible to obtain up to something around 10 minutes.
Before impact, Dimorphos circled around Didymos once every 11:55 h; after impact, an orbit takes only 11:23 h. This represents a “gain” 25 times greater than expected, generating a 4% change in the asteroid’s orbital period – these measurements have a margin of uncertainty of approximately 2 minutes, plus or minus.
Impact effects seen by the LiciaCube satellite, which followed the DART spacecraft and filmed everything up close.
More information about Dart :
DART was launched by NASA on November 24, 2021. The spacecraft was accompanied by another craft called LICIACube, supplied by the Italian Space Agency, and separated from DART just 15 days before impact. LICIACube remained in orbit around the asteroid and took photographs of the impact and material ejected from the asteroid’s surface.