The artificial crater created by the Hayabusa2 spacecraft on the surface of asteroid Ryugu in April last year is semicircular and has about 14.5 meters in diameter, a research team including the Japan Aerospace Exploration Agency, or JAXA, said Friday.
The team published an article detailing the experiment to make the crater in the online edition of U.S. journal Science on the day.
On April 5, 2019, Hayabusa2 separated a small carry-on impactor (SCI) at an altitude of about 500 meters above the equator of the asteroid. The SCI was exploded about 40 minutes later using a timer to release a metal object, which collided into the surface of Ryugu to produce the crater.
The experiment was recorded by a camera while the Japanese spacecraft landed on Ryugu at a point near the crater and collected samples of the asteroid. Footage from the camera showed, for more than 500 seconds, a phenomenon called "ejecta curtain," in which a plume of materials, including sand, from the collision, spread like a curtain.
The ejected matters spread only to the north side of the point of impact because they were blocked by a large rock just south of the site, causing the crater to become semicircular, not circular, as a result.