The pre-designated search area for the missing flight MH370 has been covered, completely. By usual mathematical estimates, there is nowhere left to look. So what happens if we never find MH370?

CNN has a good round up of scenarios, below. But first, a few videos to get you back up to speed.

1. It will go down as one of the world’s most enduring mysteries

The disappearance of Flight 370 would rank right up there with Amelia Earhart. This story has intrigued folks for generations.

The swashbuckling aviatrix and pioneering woman embarked on the first around-the-world flight at the Equator in June 1937. After completing about two-thirds of the flight, she and navigator Frederick Noonan disappeared.

A search never found any trace of her, Noonan or their plane. Some believe they ran out of fuel and crashed into the sea — similar to one theory of what happened to the Malaysia Airlines plane.

Then there’s the Bermuda triangle.

Many ships, planes and people have disappeared in this section of the Atlantic Ocean — a “triangle” marked by the points of Bermuda, Miami and San Juan, Puerto Rico.

U.S. officials cite hurricanes, sudden storms, the powerful Gulf Stream and shallow Caribbean waters as reasonable explanations for the lost vessels.

But so far, there’s been no explanation for Flight 370’s disappearance.

Of course, not all mysteries last forever.

It took two years for search parties to recover the black box from Air France Flight 447, which crashed into the Atlantic Ocean on June 1, 2009, en route to Paris from Rio with 228 people aboard.

Sometimes even when you know just about where something is, it’s hard to find.

There was no GPS and sea charts in 1912 when the RMS Titanic went down on its maiden voyage in the North Atlantic. It wasn’t until 1985 that the British luxury liner was found.

Seventy-three years is a long time to wait, but some answers take time.

CLICK HERE to read CNN’s four other hypotheses.

[Source : CNN]