An international mission to rescue a sick US scientist is under way in the depths of an Antarctic winter.
An Australian Airbus A319 has landed at an icy runway of the US McMurdo station, after a five-hour flight from Christchurch in New Zealand.
The US requested help from Australia, saying the scientist - who has not been identified - may require treatment beyond that available at the base.
New Zealand's air force is monitoring the rescue operation.
"The patient is currently stable but may require immediate corrective surgery," a statement by the US National Science Foundation (NSF) said.
It added that the base was "not equipped for the type of procedure being contemplated".
It was not immediately known when the Australian aircraft would leave McMurdo.
The base's runway is one of the few in the Antarctic that remains operational for much of the year, despite the polar darkness and hostile conditions.