Japanese spacecraft Hayabusa2 drops 'bomb' on asteroid Ryugu

In this computer graphics image released by the Japan Aerospace Exploration Agency (JAXA), the Hayabusa2 spacecraft is seen above on the asteroid Ryugu. Photo / AP

Japan's space agency said its Hayabusa2 spacecraft released an explosive onto an asteroid to make a crater on its surface and collect underground samples to find possible clues to the origin of the solar system.

Friday's crater mission is the riskiest for Hayabusa2, as it had to immediately get away so it won't get hit by flying shards from the blast.

The Japan Aerospace Exploration Agency, or JAXA, said that Hayabusa2 dropped a "small carry-on impactor" made of copper onto the asteroid Friday morning, and that the spacecraft safely evacuated and remained intact. JAXA is analysing further details.

Hayabusa2 spacecraft is shown after its successful touchdown. Photo / AP

The copper explosive is the size of a baseball weighing 2 kilograms (4.4 pounds).

JAXA plans to send Hayabusa2 back to the site later, when the dust and debris settle, for observations from above and to collect samples from underground that have not been exposed to the sun or space rays. Scientists hope the samples will be crucial to determine the history of the asteroid and our planet.

If successful, it would be the first time for a spacecraft to take such materials. In a 2005 "deep impact" mission to a comet, NASA observed fragments after blasting the surface but did not collect them.

After dropping the impactor, the spacecraft was to move quickly to the other side of the asteroid to avoid flying shards from the blast. While moving away, Hayabusa2 was also to leave a camera to capture the outcome, which would take time to reach Earth for analysis.

Hayabusa2 successfully touched down on a tiny flat surface on the boulder-rich asteroid in February, when the spacecraft also collected some surface dust and small debris.

The rocky surface of asteroid Ryugu is seen in this photo taken in September by a robot launched from the Hayabusa2. Photo / Supplied

The craft is scheduled to leave the asteroid at the end of 2019 and bring surface fragments and underground samples back to Earth in late 2020.

The asteroid, named Ryugu after an undersea palace in a Japanese folktale, is about 300 million kilometres (180 million miles) from Earth.

- AP