NASA has just deliberately crashed a spacecraft into an asteroid to see if it can alter its orbit.
The asteroid is called Dimorphos, and it orbits another asteroid called Didymos.
It was fascinating to watch. NASA’s live feed began at about 10.15 BST, at which point the Didymos/Dimorphos pair was visible as just a small dot a few pixels wide from the onboard camera. At that stage, impact was about an hour and half away. It was basically a live video with a frame rate of a few seconds, and at the start nothing much was happening.
As time ticked by, the dot became larger, and then it became possible so discern Dimorphos to the upper right of the frame (top image).
As impact time approached, things changed rather more quickly. Detail on Didymos became visible, and Dimorphos came clearly into view. Then, Didymos passed out of frame as the spacecraft autonomously targeted Dimorphos.
Impact then occurred with a final view of the surface of Dimorphos.
It was great watching it (you can see the recording on YouTube). It now remains to find out if the orbit has been altered in any way.
DART was accompanied by LiciaCube, which monitored the collision from about 50km away, and pictures from that should appear shortly (over the next few days) – which will also be interesting. However, it will be a while before they know if the orbital period has changed, indicating a successful outcome of the overall experiment.
But whatever. It is success enough to have targeted something about 160m wide and nearly 7 million miles away so accurately using autonomous control within the probe like this. Another NASA success, no matter how you look at it.