(CNN) -- A Chinese satellite looking into the mysterious disappearance of Malaysia Airlines Flight 370 "observed a suspected crash area at sea," a Chinese government agency said -- a potentially pivotal lead into what has been a frustrating search for the aircraft.
China's State Administration for Science, Technology and Industry for National Defense announced the discovery, including images of what it said were "three suspected floating objects and their sizes."
The objects aren't small: 13 by 18 meters (43 by 59 feet), 14 by 19 meters (46 by 62 feet) and 24 by 22 meters (79 feet by 72 feet). For reference, the wingspan of an intact Boeing 777-200ER like the one that disappeared is about 61 meters (200 feet) and its overall length is about 64 meters (210 feet).
The images were captured on March 9 -- which was the day after the plane went missing -- but weren't released until Wednesday.
The Chinese agency gave coordinates of 105.63 east longitude, 6.7 north latitude, which would put it in waters northeast of where it took off in Kuala Lumpur, Malaysia, and south of Vietnam, near where the South China Sea meets the Gulf of Thailand.
"It's where it's supposed to be," Peter Goelz, a former National Transportation Safety Board managing director, told CNN's Jake Tapper, noting the "great skepticism" about reports the plane had turned around to go back over Malaysia. "I think they've got to get vessels and aircraft there as quickly as humanly possible."
This isn't the first time authorities have announced they were looking at objects or oil slicks that might be tied to aircraft. Still, it is the latest and comes on the same day that officials, rather than narrowing the search area, more than doubled it from the day earlier to nearly 27,000 square nautical miles (35,000 square miles).
Bill Palmer -- author of a book on Air France's Flight 447, which also mysteriously went missing before its remnants were found -- said having a search area of that size is immensely challenging. He compared it to trying to find something the size of a car or truck in Pennsylvania, then widening it to look for the same thing in all of North America.
"It's a very, very difficult situation to try to find anything," Palmer told CNN's Brooke Baldwin. "Looking for pieces on the shimmering water doesn't make it any easier."
The Chinese satellite find could help, significantly, in that regard.
"I think the size of the pieces ... everything we've heard... gives good cause to believe that we've now (refocused) the area," former Federal Aviation Administration official Michael Goldfarb told CNN. "And that's a huge relief to everybody ... I think it's a high chance that they're going to confirm that these (are) pieces of the wreckage."
But not every expert was convinced this is it. Clive Irving, a senior editor with Conde Nast Traveler, said that the size of the pieces -- since they are fairly square and big -- "don't conform to anything that's on the plane."
Regardless, time is of the essence -- both for investigators and the loved ones of the plane's 239 passengers and crew, who have waited since Saturday for any breakthrough that would provide closure.
The flight data recorders should "ping," or send out a signal pointing to its location, for about 30 days from the time the aircraft set off, noted Goldfarb. After that, Flight 370 could prove exponentially harder to find.
Vietnamese minister: Info being provided 'insufficient'
The Malaysia Airlines flight set off seemingly without incident Saturday, not long after midnight, en route to Beijing.
Then, around 1:30 a.m., all communication was cut off. Authorities haven't said much, definitively, about what they believe happened next.
That and the fruitless search has frustrated some like Phan Quy Tieu, Vietnam's vice minister of transportation, who characterized the information that Malaysian officials have provided as "insufficient."
"Up until now we only had one meeting with a Malaysian military attache," he said.
For now, Vietnamese teams will stop searching the sea south of Ca Mau province, the southern tip of Vietnam, and shift the focus to areas east of Ca Mau, said Doan Luu, the director of international affairs at the Vietnamese Civil Aviation Authority.
At a news conference Wednesday, Malaysian transportation minister Hishamuddin Bin Hussein defended his government's approach.
"We have been very consistent in the search," he said.
Confusion over flight path
But even figuring out where authorities believe the plane may have gone down has been a difficult and shifting proposition.
In the immediate aftermath of the plane's disappearance, search and rescue efforts were focused on the Gulf of Thailand, along the expected flight path between Malaysia and Vietnam.
Over the weekend, authorities suddenly expanded their search to the other side of the Malay Peninsula, in the Strait of Malacca, where search efforts now seem to be concentrated.
That location is hundreds of miles off the plane's expected flight path.
An explanation appeared to come Tuesday when a senior Malaysian Air Force official told CNN that the Air Force had tracked the plane to a spot near the small island of Palau Perak off Malaysia's west coast in the Strait of Malacca.
The plane's identifying transponder had stopped sending signals, too, said the official, who declined to be identified because he was not authorized to speak to the media.
Malaysia's civilian administration appeared to dispute the report, however.
The New York Times quoted a spokesman for the Malaysian prime minister's office as saying Tuesday that military officials had told him there was no evidence the plane had flown back over the Malay Peninsula to the Strait of Malacca.
The Prime Minister's office didn't immediately return calls from CNN seeking comment.
Then, in another shift, Malaysian authorities said at a news conference Wednesday that radar records reviewed in the wake of the plane's disappearance reveal an unidentified aircraft traveling across the Malay Peninsula and some 200 miles into the Strait of Malacca.
However, it wasn't clear whether that radar signal represented Malaysia Airlines Flight 370, Gen. Rodzali Daud, head of the Malaysian Air Force, said at the news conference.
Rodzali said that officials are still "examining and analyzing all possibilities" when it comes to the plane's flight path.
Malaysian officials are asking experts from the U.S. Federal Aviation Authority and National Transportation Safety Board to help them analyze the radar data.
The FAA said Wednesday that it "stands ready to provide any necessary additional support." The agency has already sent two technical experts and another official to Kuala Lumpur as part of a NTSB investigative team.
The search zones includes huge swaths of ocean on each side of the Malay Peninsula, as well as land.
Forty-two ships and 39 planes from 12 countries have been searching the sea between the northeast coast of Malaysia and southwest Vietnam, the area where the plane lost contact with air traffic controllers.
But they are also looking off the west coast of the Malay Peninsula, in the Strait of Malacca, and north into the Andaman Sea.
What happened leading to the plane's disappearance also remains a mystery. Leading theories include hijacking, an explosion or a catastrophic mechanical failure.
Suggestions that the plane had veered off course and that its identifying transponder was not working raise obvious concerns about a hijacking, analysts tell CNN. But a catastrophic power failure or other problem could also explain the anomalies, analysts say.
In a sign authorities are looking at all options, Kuala Lumpur police told CNN they are searching the home of the airliner's Capt. Zaharie Ahmad Shah.
They were also questioning a man who hosted two Iranians who boarded the flight on stolen passports, the man -- Mohammad Mallaei -- told CNN on Wednesday.
Authorities have previously said they do not believe the men had any connection to terror groups.
As the vexing search drags on, frustration has grown among friends and family of those who were on board.
"Time is passing by. The priority should be to search for the living," a middle-aged man shouted before breaking into sobs during a meeting with airline officials in Beijing on Tuesday. His son, he said, was one of the passengers aboard the plane.
Other people at the meeting also voiced their frustration at the lack of information.
Most of those on the flight were Chinese, and the Chinese government has urged Malaysia to speed up the pace of its investigation.
Malaysian Prime Minister Najib Razak on Wednesday appealed for patience.
"The families involved have to understand that this is something unexpected," Najib said. "The families must understand more efforts have been made with all our capabilities."
Jethro Mullen wrote from Hong Kong; Michael Pearson wrote from Atlanta; CNN's Khushbu Shah, Kathy Quiano, Sarita Harilela, David Molko, Pauline Chiou, Steven Jiang and journalist Ivy Sam contributed to this report.