Bad weather delays Japanese asteroid probe

Japan's space agency has delayed the Saturday launch of the Hayabusa-2 spacecraft - set to land on a carbon-rich asteroid named 1999 JU3 - due to bad weather.

Scheduled to lift off from the Tanegashima Space Centre in Japan, Hayabusa-2's target is a 900-metre-long space rock that is thought to hold chemical secrets from the solar system's infancy, a report in the scientific journal Nature said.

The launch can now be expected Dec 1.

Hayabusa-2 is a beefed-up version of the first Hayabusa spacecraft which touched down on the asteroid Itokawa in 2005 and returned to Earth five years later.

Itokawa was the world's first mission to bring back asteroid dust.

Scientifically, the first Hayabusa confirmed a suspected link between the compositions of certain classes of asteroids and meteorites and discovered evidence of space weathering and other recent cosmic changes.

Hayabusa-2 aims to raise the bar with an ambitious suite of experiments to probe the asteroid 1999 JU3.

This space rock is a 'C-type' asteroid, meaning that it is darker and probably more carbon-rich than the 'S-type' Itokawa.

"The goal is to collect material that is relatively unchanged from 4.5 billion years ago, when gas and dust were clumping into particles around the newborn Sun. The asteroid may contain organic compounds, hints of water, or both," the report said.

"We think of C-type asteroids as being less altered than others. Bringing that material back and being able to look at it in the lab - I think it is going to be very exciting," said Lucy McFadden, planetary scientist at NASA's Goddard Space Flight Centre in the US.

The Japanese lander team is taking lessons from the European Space Agency's Philae lander which touched down on comet 67P/Churyumov-Gerasimenko earlier this month.