In April, Hayabusa shot the asteroid with a copper plate projectile, in order to loosen the rocks and expose the material under the surface, making it easier to harvest valuable samples. Initial images transmitted from Hayabusa2 show sample pieces with different colours and sizes, a sign of diversity even on a tiny asteroid, he said.
The Japan Aerospace Exploration Agency (JAXA) launched Hayabusa-2 into space in December 2014. Probe has created an artificial crater on the asteroid's surface and will soon begin to collect rocks.
Hayabusa2 is the successor to JAXA's first asteroid explorer, Hayabusa - Japanese for falcon, which returned with dust samples from a smaller, potato-shaped asteroid in 2010.
A Japanese spacecraft has touched down on a faraway asteroid, where it will collect space rock that may hold clues to how the Solar System evolved. Subsurface materials that were thrown out by the impact are believed to have piled up around the crater to a height of about 1 centimeter.
Then in April, the probe fired an explosive device called an "impactor" to create a crater on Ryugu's surface and bring up materials that have not been exposed to millennia of weathering.
He said JAXA plans to send the spacecraft, which was on its way back to the home position above the asteroid, to examine the landing site from above.
Thursday's touchdown was planned to gather flawless materials from underneath the outside of the space rock that could give experiences into what the close planetary system resembled at its introduction to the world, some 4.6 billion years back.
"We've collected a part of the solar system's history", said Project Manager, Yuichi Tsuda, at a news conference in Sagamihara, Kanagawa Prefecture, Japan. It took its first sample from the asteroid's surface in February.
Hayabusa2 reached its stationary position above Ryugu in June previous year after traveling 3.2 billion km.
The complex multi-year mission has also involved sending rover and robots down to the surface.
With one of its most critical missions now finished, the next task is to get Hayabusa2 to safely return to Earth with the samples, Tsuda said.
Hayabusa2 has travelled around 4 billion km around the Sun in an elliptical orbit since its launch in December 2014.
The probe is expected to drop a re-entry capsule containing its samples back to Earth in late 2020.
The Hayabusa2 mission has attracted worldwide attention, with Queen guitarist and astrophysicist Brian May sending a video to the probes team ahead of the landing.