The disappearance of Malaysia Airlines Flight MH370 is the kind of mystery that's not supposed to be possible anymore.

The Information Age is also the age of surveillance, of interconnectedness, of cloud computing, of GPS satellites, of intelligence agencies that can monitor terrorists from space or call in a drone strike from a control console on the other side of the world.

But so far, all the technological eyes and ears of the world have failed to find the missing plane. The Boeing 777 jetliner, with 239 people aboard, silently vanished early Saturday morning on its way to China, disappearing from radar so suddenly and inexplicably that it might as well have flown into another dimension.

The civilian and military assets of multiple nations, including the United States, are being devoted to the search for wreckage on both sides of the Malay Peninsula, in the Gulf of Thailand and the Strait of Malacca. A Colorado commercial satellite firm, DigitalGlobe, is crowdsourcing the hunt by asking volunteers to scan images for signs of the plane.

But the satellite coverage of the planet isn't as complete as some people might assume.

"Despite the impression that people get when they use Bing and Google Earth and Google Maps, those high-resolution images are still few and far between," said John Amos, president of SkyTruth, a nonprofit organization that uses such images to engage the public on environmental issues.

The pilots of Flight MH370 never communicated distress. No one activated an SOS signal. No debris or fuel slick has been found. The plane's flight recorders may be on the sea floor, buried in sand.

Scenarios abound. Did the plane disintegrate at 35,000 feet from a mechanical failure and sudden decompression? Did the pilot commit suicide by flying it straight down into the sea? Did terrorists blow it up? Did a passenger plant a bomb so that his family would collect life insurance? Was the plane shot down by a jumpy military? Could it have crash-landed in a jungle somewhere, where the passengers are now fighting to survive?

From a long list of possibilities that range from the unlikely to the extremely far-fetched, the truth about what happened to Flight MH370 will probably emerge eventually. For now, it's the mystery of the year — and a source of immense anguish for the families of the missing passengers and crew.

There were media reports Tuesday, quoting Malaysia's air force chief, Gen. Rodzali Daud, saying that military radar picked up the plane Saturday flying far off-course, to the west, hundreds of miles from its scheduled flight path.

That would suggest foul play — for example, a cockpit intrusion and forced diversion — if the reports hold up. But these reports still do not reveal where the plane is, whether it crashed on land or at sea, or is intact somewhere.

"As we enter into Day 4, the aircraft is yet to be found," Malaysia Airlines said Tuesday in the company's 11th media update.

The airline noted reports that the plane may have changed direction.

"All angles are being looked at," the airline said. "We are not ruling out any possibilities."

"I can't think of an airplane getting lost for a long period of time — not a modern, regular airliner with all the communications equipment," said San Diego-based aviation consultant Hans Weber. "Sometimes a small plane disappears and it's not found for a small time, but this a completely different matter."

One possibility, he said, is that an engine malfunction could have sent a turbine disk through the plane's fuselage and caused an instant, catastrophic decompression. But that is very rare during the cruising portion of a flight and would not explain the lack of debris on the sea surface.

The plane had a transponder to signal where it was flying, but the signal vanished over the Gulf of Thailand. Someone could have turned it off intentionally and then diverted the plane to the west, Weber said. He said there was enough fuel aboard to fly at least 1,800 miles .

"That airplane could have landed somewhere," he said. But he acknowledged that this is extremely unlikely, because word of the secret landing would surely have gotten out by now.

"This whole thing is a series of puzzles and, frankly, red herrings," said Washington-based aviation analyst Richard Aboulafia of Teal Group.

Aboulafia expects the wreckage to be found relatively soon.

"This is a big jet. This is a wide-body," he said. "That means a lot of structure, a lot of components, a lot of luggage, a lot of fuel. You can't make it all go away, even if you hit perpendicularly. It doesn't all go straight, sucked into the sea bed. It's going to be found."

The case has some similarities to that of Air France Flight 447, which crashed into the Atlantic after leaving Rio de Janeiro, killing all 228 people aboard, in 2009. But in that case, when airspeed measurements failed and led pilots to put the plane into a stall, the computers on the plane sent error messages to computers on land before the plane disappeared.

Wreckage on the sea surface was spotted five days after the crash, and eventually most of the bodies were recovered, though it took two years for the black-box flight recorder to be retrieved from the sea floor.

The lack of a solid explanation for the Malaysia Airlines disappearance has spawned rampant speculation. Two Iranian passengers travelling with stolen passports do not appear to have any connection to terrorist groups, intelligence officials have told reporters.

Weber, the aviation consultant, said a case such as this captures our attention in part because we like to think such things can't happen.

"We like to think that we're in control. That's our culture," Weber said. "Not knowing means you're not in control. That's hard for us to take."

The missing plane may be a mystery, but the search for answers is likely to produce some sooner rather than later. Space aliens don't abduct Boeing jetliners. Anyone wondering whether there's the equivalent of the Bermuda Triangle off the coast of Southeast Asia should remember that the Bermuda Triangle is a myth.

The plane is out there somewhere.

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Washington Post staff writers Simon Denyer in Beijing and Ashley Halsey III in Washington contributed to this report.