As dawn broke drizzly and windy Friday over the Indian Ocean, aircraft resumed looking for two small pieces of possible evidence of what might have happened to Malaysia Airlines Flight 370.
Three military jets and a civilian Gulfstream from Australia were headed on flights to one of the most remote places on Earth — a patch of the open ocean about 1,500 miles from the southwest coast of Australia. They were being joined later by a U.S. Navy P8 Poseidon.
They were looking for two "indistinct" objects that Australian authorities said popped up in satellite imagery as numerous nations scoured an enormous area looking for the jetliner that vanished 13 days ago without a trace — at least, perhaps, until now.
One of the objects is about 79 feet long and the other is about 16 feet long — and they're about 14 miles apart, the Australian Maritime Safety Authority said.
Conditions Friday were relatively moderate — mostly cloudy with light showers and winds from the east at 10 to 20 mph, said Dale Eck, director of the global forecasting for The Weather Channel.
But the Australian maritime agency reported that visibility remained poor amid waves of 5 to 10 feet in mixed, eddying currents. Gusts can create enormous waves of 20 feet and higher.
Conditions like that mean the objects have probably floated far from where they first entered the ocean, Greg Ivey, a professor of geophysical fluid dynamics at the Oceans Institute at the University of Western Australia, told NBC News on Thursday — meaning the real center of whatever created the debris could be several hundred miles away.
The round trip for the searchers is about eight hours — severely limiting how long the jets can stay in the air over the site before they have to return so they don't run out of fuel.
Cmdr. William J. Marks, a spokesman for the U.S. Navy's 7th Fleet, said the P-8 that flew to the scene from Perth on Thursday was able to remain only three hours before it had to turn back. Australian authorities said their jets might be able to stay only two hours.
The flight time to the new search area is among the lesser obstacles in what experts assessed as one of the most difficult recovery efforts in aviation history — one that Australian Defense Minister David Johnston called "a logistical nightmare."
The search was suspended Thursday night because weather in the area was "extremely bad," with the captain of the first Australian air force plane to return from the area reporting rough seas and high winds, The West Australian newspaper of Perth reported.
Likewise, a New Zealand Orion jet that reached the debris zone late Thursday reported that "visibility wasn't very good," Kevin Short, air vice marshal of the New Zealand Defense Forces, told Radio New Zealand.
Besides the New Zealand jet, two Royal Australia Air Force Orions, a U.S. Navy P-8 Poseidon and six merchant vessels were involved in the search Thursday.
And the first ship to reach the search area — the Hoegh St. Petersburg, a Norwegian cargo ship — searched through the night and into Friday.
"We consider this an emergency situation, and we will continue until further notice," Ingar Skiaker, chief executive of Hoegh Autoliners, told reporters in Oslo.
"If there are any survivors spotted, we will have the means to take them on board," he said.
The area is historically notorious among aviators and sailors for its heavy, swelling waves, whipped up by winds that roar unimpeded by any land even remotely nearby.
"It is a pretty energetic part of the ocean — it's hostile," Ivey said.