In what officials called the "best lead" of the nearly two-week-old aviation mystery, a satellite detected two objects floating about 1,000 miles off the coast of Australia and halfway to the desolate islands of the Antarctic.
The development raised new hope of finding the vanished jet and sent another emotional jolt to the families of the 239 people aboard.
But Australian authorities said in a statement early Friday that the search had turned up nothing so far.
One of the objects on the satellite image was 24 meters (almost 80 feet) long and the other was 5 meters (15 feet). There could be other objects in the area, a four-hour flight from southwestern Australia, said John Young, manager of the Australian Maritime Safety Authority's emergency response division.
"This is a lead, it's probably the best lead we have right now," Young said. He cautioned that the objects could be seaborne debris along a shipping route where containers can fall off cargo vessels, although the larger object is longer than a container.
Four military planes searched the area Thursday without success and planned to resume Friday morning, Australian officials said.
The Norwegian cargo vessel Hoegh St. Petersburg, with a Filipino crew of 20, arrived in the area and used searchlights after dark to look for debris. It will continue the search Friday, said Ingar Skiaker of Hoegh Autoliners, speaking to reporters in Oslo.
The Norwegian ship, which transports cars, was on its way from South Africa to Australia, he said. The Australian Maritime Safety Authority said another commercial ship and an Australian navy vessel were also en route to the search area.
Satellite imagery experts said the lead is worth investigating.
"It would be very nice if you could see a whole wing floating there, then you could say, 'OK that's an airplane.' When you're looking at something like this you can't tell what it is," said Sean O'Connor, an imagery analyst with IHS Janes.
But another analyst said the debris is most likely not pieces of Malaysia Airlines Flight 370. There have been several false leads since the Boeing 777 disappeared March 8 above the Gulf of Thailand en route from Kuala Lumpur to Beijing.
"The chances of it being debris from the airplane are probably small, and the chances of it being debris from other shipping are probably large," said Jason Middleton, an aviation professor at the University of New South Wales in Sydney.
The development marked a new phase for the anguished relatives of the passengers, who have been critical of Malaysian officials for not releasing timely information about the plane. While they still hope their loved ones will somehow be found, they acknowledged that news of the satellite images could mean the plane fell into the sea.
"If it turns out that it is truly MH370, then we will accept that fate," said Selamat Bin Omar, the father of a Malaysian passenger. The jet carried mostly Chinese and Malaysian nationals.
But he cautioned that relatives still "do not yet know for sure whether this is indeed MH370 or something else. Therefore, we are still waiting for further notice from the Australian government."
Malaysian officials met with the relatives Thursday night in a hotel near Kuala Lumpur, but journalists were kept away. After the meeting, groups of people left looking distraught.
Hamid Amran, who had a child on Flight 370, said questions asked at the meeting made it "apparent that Malaysia's military is incapable of protecting its own airspace."
He said he "believes that my child and all the other passengers are still alive. I will not give up hope."
A man who would only give his surname, Lau, said he was there to support a Chinese couple who had lost their only son.
"It appears some families are slowly accepting the worst outcome," he said.
Malaysian Airlines CEO Ahmad Jauhari Yahya said the relatives in Kuala Lumpur were being given updates by high-level officials "two or three times a day."
"We do take care of the next of kin, and assuming it is confirmed, that the aircraft is located somewhere close to Australian, we will obviously make arrangements to fly the next of kin there," he said.
A group of Malaysian government and airline officials flew Thursday night to Beijing to meet families there.
Young said the ocean in the search area is thousands of meters (feet) deep.
DigitalGlobe, a Longmont, Colo.-based company, said it provided the images to Australian officials. The Australian Maritime Safety Authority released two images of the whitish objects. They were taken March 16, but Australian Air Commodore John McGarry said it took time to analyze them.
"The task of analyzing imagery is quite difficult, it requires drawing down frames and going through frame by frame," he said.
The hunt has encountered other false leads. Oil slicks that were seen did not contain jet fuel. A yellow object thought to be from the plane turned out to be sea trash. Chinese satellite images showed possible debris, but nothing was found.
But this is the first time that possible objects have been spotted since the search area was massively expanded into two corridors, one stretching from northern Thailand into Central Asia and the other from the Strait of Malacca to the southern Indian Ocean.
Malaysian Defense Minister Hishammuddin Hussein made it clear Thursday that although international search efforts are continuing both on land and in sea in the northern and southern hemispheres, the effort is mostly concentrated south of the equator over the vast Indian Ocean.
Malaysian authorities have not ruled out any possible explanation for what happened to the jet, but have said the evidence so far suggests it was deliberately turned back across Malaysia to the Strait of Malacca, with its communications systems disabled. They are unsure what happened next.
Police are considering the possibility of hijacking, sabotage, terrorism or issues related to the mental health of the pilots or anyone else on board.
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