Last month, the pilot of missing Flight 370 reportedly deleted information from his custom-built flight simulator. At a press conference on Wednesday, Malaysian officials said investigators are trying to recover the data to see if it offers any potential clues about the plane's mysterious disappearance twelve days ago.

The search for Malaysia Airlines Flight 370 is now in its tenth day, and as authorities attempt to make sense of the plane's disappearance, and family members grapple with the likely loss of its 239 passengers, the internet is hard at work trying to figure out what happened. Some theories are obviously wrong (aliens?). Some are just probably wrong—but their plausibility has led to widespread dissemination online. Here are four of the least crazy-sounding:

Missing Malaysian Airlines Flight 370's initial turn from its planned flight route was reportedly scheduled on a computer system and programmed by someone with access to the cockpit, casting further suspicion on the plane's pilots and crew.

The US Navy determined today that their 7th Fleet, who has been involved in the search for the missing Malaysian Airlines flight MH370, will no longer be useful in the search.

Seems legit.

According to WNYC, there are 634 runways in range of the missing flight. The Atlantic's Jim Fallows points out that not all of them, though, are big enough to handle a Boeing 777.

Malaysian officials have now backtracked from yesterday's claim that Flight 370's final interaction with ground control came after the plane's communications system was deliberately shut off. "We don't know when the Acars system was switched off," Ahmad Jauhari Yahya, the CEO of Malaysia Airlines, said early Monday.

Authorities still have no idea where the missing Malaysia Airlines plane is, but they've found a new place to refocus their efforts—the pilot who said, "All right, good night," a few minutes after the plane was diverted.

In the face of emerging radar data and a week of fruitless searching, Malaysia Prime Minister Najib Razak announced on Saturday that his country believes missing Malaysia Airlines Flight 370 was deliberately taken off course.

Just after it vanished from civilian radar, Flight 370 reportedly climbed past 45,000 feet—well above the plane's approved altitude—and changed courses several times in a deliberate manner, as if it were still being steered by a pilot.

Source told Reuters on Friday that the Malaysian military has radar data indicating that Flight 370 may have deliberately flown hundreds of miles off course, raising the possibility of sabotage or hijacking.

Officials have extended the search for missing Flight 370 to the Indian Ocean, in part because of reports that the plane possibly turned west and flew for hours after losing contact with air traffic control.

U.S. investigators believe missing Malaysia Airlines Flight 370 may have flown for an additional four hours after it reached final known location, according to a report in the Wall Street Journal. If the reports are true, the plane could have traveled another 2,200 nautical miles, giving it time to reach Pakistan, the Indian Ocean, or the Arabian Sea.

The Chinese government has released satellite images of three floating pieces of debris that are believed to be from the missing Malaysian Airlines flight. The photos, taken on March 9, show the suspected wreckage in the South China Sea, just southeast of where Flight 370's transponder turned off.

Early Saturday morning, Malaysian Airlines Flight 370 vanished from radar screens and lost contact with air traffic control. Five days later, the plane is still missing. Here's what we (don't) know:

A New Zealand man working on an oil rig in the South China Sea claims he witnessed missing Malaysian Airlines Flight 370 burst into flames before disappearing.

Flight MH370's final radio message signaled that everything on board was normal. "All right, roger that," the flight's pilot replied to Malaysian air control, just minutes before the plane vanished over the the South China Sea.

The Malaysian military reportedly has radar data showing that Malaysia Airlines Flight 370 changed course and made it to the Malacca Strait, hundreds of miles from its last reported location, before vanishing early Saturday morning. UPDATE 10:05 PM: Malaysia's air force chief has denied the report.

Malaysian police announced on Tuesday that one of the two men traveling on missing Malaysian Airlines Flight 370 with a stolen passport was a 19-year-old Iranian trying to migrate to Germany, where his mother lives. The second man using a fake passport was later identified as Delavar Seyed Mohammad Reza, a 29-year-old Iranian.

A Malaysian official announced on Monday that the miles-long oil slick spotted on Saturday did not come from missing Malaysian Airlines Flight 370, which vanished off the coast of Vietnam early Saturday morning with 239 people on board.