"This 'stranger' was object 46477, internationally registered as 2018-084CQ. It is a fragment of the second stage of Japan's H-2A rocket, which exploded in February 2019," the source said.
According to the source, the rocket launched into space six satellites, including Ibuki-2 greenhouse gases observing satellite, back in October 2018.
According to data of the US Air Force, available on space-track.org website, the explosion of the second stage of Japan's rocket had led to the emergence of over 75 pieces of debris in space.