(CNN) -- Images of possible debris from Malaysia Airlines Flight 370 have been captured on satellite in the southern Indian Ocean. The best lead yet on where the missing plane might be has prompted a massive search in the area more than 1,500 miles southwest of Australia.
The Boeing 777 took off from Kuala Lumpur March 8 with 239 people aboard, bound for Beijing.
When will we know whether the debris that's been spotted in the southern Indian Ocean is from missing Malaysia Airlines Flight 370?
John Young, general manager of emergency response for the Australian Maritime Safety Authority, says it will be a lengthy process.
"We have to locate it, confirm that it belongs to the aircraft, recover it and then bring it a long way back to Australia, so that could take some time."
Satellites captured images of the objects Sunday about 14 miles (23 kilometers) from each other and about 1,500 miles (2,400 kilometers) southwest of Australia's west coast. The area is a remote, rarely traveled expanse of ocean far from commercial shipping lanes.
Would pieces of the plane still be floating?
If the plane crashed into the water, large pieces would not still be floating by now, according to Steve Wallace, the U.S. Federal Aviation Administration's former director of accident investigation. But pieces of lightweight debris, not aircraft structure, could be floating days after the aircraft struck the water, he said. That could include life jackets and seat cushions.
Is it possible that the plane would have gone that far?
Mitchell Casado, a flight instructor on a 777 flight simulator, said that running out of gas would be a big concern. "There's such few options," he said. "As long-range as this aircraft is, it's a long way to any suitable airport out there. There are some small islands, you know, that you could possibly land at, but that would really be pushing your -- the limits of the airplane. So I would really be worried about running out of gas."
The 777, when fully fueled, can go 16 to 18 hours. Flight 370 wasn't.
Some planes flew over the area, and a ship went there. What did they find?
Four aircraft -- two from Australia, one from New Zealand and one from the United States -- flew into the search area but found nothing of note. A Norwegian cargo ship also arrived in the area Thursday afternoon but had not found anything as of nightfall. The searches were hindered by low visibility and rough seas in the region, a wild and remote stretch of ocean rarely traveled by commercial shipping or aircraft. A second merchant ship is steaming to the area, as is the HMAS Success, an Australian naval vessel that is still several days away. China and Malaysia are also sending vessels to the area, they said Thursday.
If it's not the plane, what else could it be?
Almost anything big and buoyant. The objects were spotted in a part of the Indian Ocean known for swirling currents called gyres that can trap all sorts of floating debris. Among the leading contenders for what the objects might be, assuming they're not part of Flight 370: shipping containers that fell off a passing cargo vessel. There are reasons to doubt that theory, however. The area isn't near commercial shipping lanes, and the larger object, at an estimated 79 feet (24 meters), would seem to be nearly twice as long as standard shipping containers.
If it is the plane, would its location tell us anything about what happened on that flight?
If it really is the wreckage of the Boeing 777-200, its far southern location would provide investigators with precious clues into what terrible events unfolded to result in the disappearance and loss of the airliner, according to Robert Goyer, editor-in-chief of Flying magazine and a commercial jet-rated pilot. "The location would suggest a few very important parameters. The spot where searchers have found hoped-for clues is, based on the location information provided by the Australian government, nearly 4,000 miles from where the airliner made its unexpected and as yet unexplained turn to the west," Goyer wrote. The first obvious clue is that the airplane flew for many hours.
What do the satellite images show?
Two indistinct objects, one about 79 feet (24 meters) in length and the other about 16 feet (5 meters) long. Though they don't look like much to the untrained observer, Australian intelligence imagery experts who looked at the pictures saw enough to pass them along to the maritime safety agency, Young said. "Those who are expert indicate they are credible sightings. And the indication to me is of objects that are reasonable size and are probably awash with water, bobbing up and down out of the surface," he said.
How old are the satellite images?
They were taken by commercial satellite imaging company DigitalGlobe on Sunday.
Why are we just hearing about them now?
Basically, the Australians say, it's because the Indian Ocean is a very big place. The maritime safety authority said it took four days for the images to reach it "due to the volume of imagery being searched and the detailed process of analysis that followed."
How did they know to look in this area?
This southern area is where searchers believe there is the most likelihood of the plane being found. U.S. officials have also said the southern corridor is where the plane is most likely to be.
The searchers used mathematics to narrow the likely area to a square -- and that is where these images have emerged.
Who is running the search?
The Australians are in charge of the search in their area of responsibility, which includes a large area of the southern Indian Ocean off Australia's west coast. Malaysia remains in overall control of the search.
How long does the flight data recorder ping?
It would be difficult to pick up ultrasonic "pingers" from the data recorders. In this vast expanse of ocean, the range of the pingers in the best conditions may be about 2 miles. If they are at the bottom of the ocean, that really limits how far they can go, especially in warm waters. The warmth of the water may impede the pingers because of the presence of thermoclines, or layers of different temperatures in the water that affect the ability of the pingers to be heard. The recorders' batteries die after about 30 days.