(CNN) -- Malaysia Airlines Flight 370, a Boeing 777 on the way from Kuala Lumpur to Beijing, simply vanished from the sky on March 8. In the two weeks since, the mystery of what happened to its 227 passengers and 12 crew members has set off a frenzy of speculation and conspiracy theory hatching.
It was a rogue pilot. Or was it a hero pilot? Terrorists took over the plane. Or were they air pirates? Space aliens? Maybe the crew flew the plane into Pakistan. Or a black hole? Somebody shot it down. Aha! We can't see the plane because it's invisible! No, it's a sign from God that the Rapture is coming! The Illuminati are behind this! And last but not, least here's that old Internet standby so popular among conservative conspiracy theorists: It's Obama's fault.
Pop-culture aficionados have weighed in, too, with comparisons to the television series "Lost" and "Fantasy Island." Singer Courtney Love went to her Facebook fan page and posted a helpful map drawn on a satellite photo; she said it showed the wreckage in the waters near the island of Palau Perak.
And YouTube commenters suggested that Pitbull and Shakira might have foreseen the trouble, pointing to their 2012 song "Get it Started." They ponder this lyric: "Now it's off to Malaysia," Pitbull sings, "Two passports, three cities, two countries, one day."
Outlandish as some of these theories sound, they are so much more comforting than the truth. The truth is unfathomable. The truth is, we just don't know. We can't know yet and we might never know. Highly trained professionals can't figure it out, even with all their satellites and radar and pingy things. Think people don't just disappear from the sky? Tell that to folks who have spent a lifetime trying to figure out what happened to Amelia Earhart or D.B. Cooper.
The search for missing Malaysia Airlines Flight 370 "is going to be a long haul," Malaysia's acting transportation minister, Hishammuddin Hussein, said on Friday. "The focus is to reduce the area of search." Right now, it follows two possible flight paths: One arcs over parts of Cambodia, Laos, China and Kazakhstan, and the other over the Indian Ocean. No signs of the plane or a crash site have been spotted on land. And one official compared searching the ocean for the plane to "looking for a needle in a stack of needles."
Searchers and investigators from two dozen countries have pitched in but are left scratching their heads. They're checking data from satellites, running passenger background checks, dispatching ships and flying planes low over thousands of square miles of ocean, looking for a speck of something, anything, among all that rolling blue and gray. The aerial searchers are doing it the old-fashioned way, by peering out the window.
The most promising development has focused on a possible debris sighting in a remote spot in the Indian Ocean more than 1,400 miles southwest of Perth, Australia. That's roughly 6,000 miles from where Flight 370 should have landed. It takes so long to get there and back, the aerial crews can only search the vast open ocean for a two hours at a stretch. China and Japan are dispatching ships, but it will take them several days to get there. A Norwegian commercial ship that was already in the area is looking for signs of survivors. Other merchant ships are on their way, and these are practically uncharted waters.
Australian Prime Minister Tony Abbott acknowledged the debris sighting is a long shot. It could just be garbage or "a container that has fallen off a ship," he said. "We just don't know."
But people really hate not knowing such things. Mysteries drive them bonkers. And so, legions of armchair detectives have taken to the Internet to fill in the gaps. As a result, the line between fact and fiction has become a bit blurry.
First, the known facts: The plane took off at Kuala Lumpur International Airport at 12:41 a.m. on March 8. The co-pilot acknowledged a message from ground control at 1:19 a.m., saying, "All right, good night." That was the last time anybody heard a human voice coming from Flight 370.
Two minutes later, somebody or something shut down the transponder, which signals the plane's identity, altitude and speed to other aircraft and to monitors on the ground. It disappeared within a minute after that from Thai military radar, and moments later an unidentified plane popped up. It flew in the opposite direction, following a course nothing like Flight 370's course.
Within two hours, the plane was hundreds of miles off course. At about 2:15 a.m., it ascended to 45,000 feet -- higher than any 777 should fly -- then dropped in uneven increments to 23,000 feet, the New York Times reported, citing Malaysian military radar. Some experts, however, cast doubt on the accuracy of these radar readings.
The mystery plane, which officials believe was indeed Flight 370, is thought to have continued flying far off course well after it should have landed in Beijing. Satellites tracked it to somewhere over the Indian Ocean. Although nobody on the plane responded to the satellite's inquiries, an automated satellite system on the plane did emit signals; the exchanges are known as "handshakes." The last one was received at 8:11 a.m.
And then, silence.
Those are the facts as we now know them. Anything more is theory, speculation -- or pure fantasy. Some scenarios are more plausible than others; some have been debunked, and others have not.
A few other, sketchier facts have emerged. Some are not yet confirmed, while the significance of others is not yet clear. The plane's pilot, Capt. Zaharie Ahmad Shah, reportedly placed a cell phone call eight minutes before takeoff. We don't know yet to whom or what was discussed. He practiced on a flight simulator at home, and some of the data were erased, things which on their own are not particularly alarming. There could be an innocent explanation.
The flight simulator could hold valuable clues, as could the crew members' computers. The simulator's hard drive is being analyzed by the FBI, which is confident it can recover some of the deleted files. The FBI is also helping Malaysian authorities analyze crew members' computer hard drives and social media activity.
Malaysian authorities are convinced that someone deliberately altered the plane's flight path, steering Fight 370 far off course, about 12 minutes before the last communication with ground control at 1:19 a.m. They just don't know who -- or why.
The search for clues has investigators checking into the backgrounds of everyone on board that plane. And it has fed several of the major working theories, some more plausible than others.
Rogue flight crew? Capt. Zaharie, 53, has been flying for Malaysia Airlines since 1981, and his 27-year-old co-pilot, Fariq Abdul Hamid, just started flying a 777. The plane's transponder stopped signaling its location to air-traffic controllers and other planes at an oddly opportune moment -- just as it left Malaysian air control.
The transponder abruptly shut down and the plane made a sharp westward turn and appears to have kept flying for another seven hours. The plane should have appeared in Vietnam's airspace en route to Beijing, but Vietnam never heard from Flight 370. It took Thailand 10 days to acknowledge that it had tracked an unidentified plane, now assumed to be Flight 370, traveling through its airspace early on the morning of March 8.
The idea of pilots using a plane to commit suicide and mass murder is horrific, but not unprecedented. A SilkAir crash in 1997 and an EgyptAir crash in 1999 are both believed to have been the result of deliberate actions taken by pilots. Right now there is scant evidence to support this theory -- or to discount it. Searches of the pilot's flight simulator and computer hard drive may shed light.
Terrorism? In a post-9/11 world, terrorism is the first scenario that jumps to mind when things go wrong. The fact that two Iranian passengers, young men ages 18 and 28, boarded with stolen passports at first made this theory seem to be a slam-dunk. And then it was debunked.
It turns out the Iranians had no ties to any terror groups and were trying to sneak into Europe via China, not blow up the plane. No group claimed credit, and investigators weren't picking up the usual chatter. It is still possible that the passengers and crew succeeded in fighting off a terrorist takeover by someone or some group and that no one survived to fly or land the plane. Still, authorities say intelligence experts would have expected to hear some chatter about it and they haven't.
Catastrophic event? Had a bomb gone off, or the plane succumbed to engine failure, the transponder probably would have stayed on, and the debris field would have been easy to find. Pieces of the falling plane would have been visible on radar, aviation experts have said. A fire or smoke in the cabin has been suggested as the reason why nobody tried to use cell phones to call for help. This theory by pilot Chris Goodfellow gained traction after it was posted last week on Google+, but there are a few holes in it. There was no distress signal, for example. And why would the plane have appeared to keep on flying?
The Payne Stewart theory: Whether it was slow or sudden, decompression would have caused loss of oxygen and killed everyone on board. That is what happened on golfer Payne Stewart's chartered Learjet in 1999, which continued to fly on autopilot for four hours before crashing. It would explain the silence from the crew and passengers on board Flight 370, but why didn't the plane continue flying toward Beijing? Why the change in course? And why did it disappear from radar?
The shoot-down theory: Radio host Rush Limbaugh advanced the hostile shoot-down theory a week ago. "I don't know if this is possible," he said, "but let's say it is." He continued, "The jet is flying along and you have a total electronic failure, but the engines keep working. So then the crew says, 'We got to get back home. We got to get back to Kuala Lumpur. We can't fly with no electronics.' It's dark, nighttime. They fly over a bunch of unfriendly countries, and they can't identify themselves, and they're not identified, there are no lights on. There's been a total electronic failure. What if some hostile country flew up there and shot it down, and then discovered their mistake and nobody wants to admit what happened?"
Sound far-fetched? Civilian aircraft have been shot down before. In 1988, a U.S. Navy warship mistook an Iran Air flight for an attacking fighter jet and shot it down with a missile, killing all 290 passengers and crew. And in September 1983, a Russian fighter jet shot down a Korean Air Lines flight with a U.S. congressman on board. But right now, there is no evidence to support the theory that Flight 370 was brought down by a government entity.
And so, the people looking into what happened to Malaysia Airlines Flight 370 are left with the few tangible details they have. They continue to search for more. If debris is indeed found at the remote site they're searching in the southwest Indian Ocean, and it is determined to be from Flight 370, more sophisticated equipment will be brought in to scan the ocean floor for the plane's flight data recorders.
But don't expect any quick answers. When an Air France jet crashed into the Atlantic back in 2009, it took two years to find the flight data recorders more than two miles underwater.
And the authorities knew where that plane went down.