The search for the missing Malaysia Airlines plane is taking place over one of the harshest and most isolated points on the planet, in a patch of southern Indian Ocean from where Antarctica beckons.
We zoom in on the search area, and what's next.
1. What's the search area like?
Shipping veteran Tim Huxley calls it "a lonely, lonely place down there".
The search area is around 2,500km south-west of Perth, above a volcanic ridge in waters estimated to be 2,500m to 4,000m deep. Because of the influence of Antarctica, the area is lashed by strong gusts and huge waves that can be 6m and higher.
Oceanographer Erik van Sebille from Sydney's University of New South Wales, who was on a research ship in the area in December, told AFP that even in calm conditions the place is challenging, and with the southern hemisphere's autumn approaching, it is set to deteriorate.
The harsh environment makes recovery of possible debris extremely difficult. But if there is any consolation, the ocean floor in the search area seems flatter, even though it is deep, reaching about 4,000m down. When Air France flight 447 crashed into the Atlantic Ocean in 2009, wreckage sank onto a seabed containing underwater mountains and ravines, complicating recovery efforts.
2. Who travels to that part of the world?
That part of the Indian Ocean is so treacherous that it is known by sailors as the "Roaring Forties" for the rough seas and strong westerly wind that engulfs the area between latitude 40 degrees and 50 degrees, according to Australia's ABC Science.
There is no land mass in the area, and little maritime traffic. The open expanse of sea was once frequently used by sailors who took advantage of the winds, but many ships now avoid the area, said ABC Science. Global shipping routes now direct cargo ships from Australia to head north towards Asia and Europe, rather than south or west through these latitudes.
Just how remote is the area?
When alerts went out this week to merchant shipping in the area to help with locating the potential debris, the nearest vessel was two day's journey away.
Professor Nathan Bindoff, an expert in physical oceanography at the University of Tasmania, told AFP that vessels typically saw only one other ship on a 50-day voyage in the area, and then most likely closer to Antarctica and its research bases than the area where the potential wreckage was spotted.
He said: "In some ways there are more eyes near Antarctica than there are in this part of the southern ocean."
3. How difficult is it to retrieve the objects spotted on satellite?
One problem is the satellite images were taken on March 16, so the objects could have moved a large distance because of strong currents.
To give an idea of how far the objects could have travelled: For every knot, or nautical mile per hour, of current in the rough waters of the southern Indian Ocean, an object could theoretically float for 500km in 13 days, the time the Malaysian plane has been missing.
Scientists have developed computer models to "play back" the waves and winds, allowing rescue workers to retrace the movements of debris to the site of a crash.
But not all experts agree computer simulations will easily replace the gruelling routine of searching from air and sea. A detailed annex to the report on the Air France crash in 2009 raised questions over the consistency of such "retro-drift" calculations. For example, when the French Navy dropped special buoys at the same spot a year after the crash, they scattered hundreds of miles apart, highlighting the turbulence of ocean currents.
4. What's the best hope of locating the missing plane?
The best hope of finding an impact site is to concentrate efforts on detecting the acoustic signals that are being emitted from the black box recorders.
But the "pingers" have a definite life - generally 30 days - but sometimes less, sometimes more.
After the signals stop, finding a missing plane at sea becomes far more difficult, as illustrated by the hunt for the Air France plane, which crashed into the Atlantic in 2009. Investigators will have to use ships equipped with sonar to map the sea floor and search for the wreckage.
Mr David Gallo from the Woods Hole Oceanographic Institution in the United States, who was involved in the Air France search, told BBC News: "Unlike this flight, we had a very good last-known position that allowed the authorities to direct the search team. But it took five days to locate the first bits of wreckage, and the black box was never heard."
The wreckage was finally discovered and recovered in 2011 using both autonomous and remotely operated underwater robots, after search teams zoomed in on an area with a 75km radius and examined it using sonar.
5. How much is the search expected to cost?
Experts say it will be difficult and costly, but not impossible, to locate the missing plane.
The official cost for the French-led underwater search for Air France plane was 32 million euros (S$53 million), but salvage experts say the actual costs might have been three or four times higher, including Brazilian contributions and costs borne by the military.
The search efforts for the missing Malaysia Airlines plane, which involves 26 countries from the Indian Ocean to the Caspian, may be higher. Malaysian officials have not addressed who would pay for the full search operation.
Mr David Mearns, director of Blue Water Recoveries, told BBC News: "We have a saying in our industry: Almost anything can be found as long as you spend enough money.
"Air France was in the order of £20-£25m (S$42-52m). With this, you could add another zero on."
Source: Reuters, AFP