KUALA LUMPUR, March 21 — In the mystery of the missing Malaysia Airlines flight MH370, the most tantalising clues have come from satellites; they showed that the plane flew on for hours longer than previously known and gave searchers the “best lead” to the plane's location.

But most frustratingly for investigators is that while the satellites have provided the most credible information in the puzzle that is nearly two weeks old, these have also fallen just short of giving searchers what they need to learn the one thing that is one everyone's mind: Where is the plane?

Colorado, US-based DigitalGlobe's Worldview-2 satellite that took images of “debris” 2,500km southwest of Perth, Australia is touted as capable of taking high-resolution images of objects  as small as to 50cm.

But rather than clear images of a wing, tail or any other parts of the 67m-long plane, the images showed indistinct “blobs”.

“It looks to me like possibly just an exceptionally large patch of sun glint,” John Amos, president of SkyTruth, told the Washington Post.

SkyTruth uses satellite imagery to raise awareness of environmental issues.

“We’re down in the subtle and ambiguous weeds of human image analysis, where we desperately are trying to find patterns in what we’re seeing.”

One analyst explained that the shortcoming was due to the design limits of satellite imaging equipment and plain physics.

An imaging sensor can either be designed to capture a large area broadly or small patch in great detail; it cannot, however, do both well.

“Imagine driving down the street at 70 miles an hour with a pair of binoculars and trying to look at every single mailbox ... you can’t slew your binoculars around fast enough,” said Brian Weeden, technical advisor to the Secure World Foundation, a nonprofit organisation devoted to space policy, told the US newspaper.

Yesterday, Australian Prime Minister Tony Abbott announced the discovery of satellite images that may be related to the Beijing-bound Malaysian Airlines flight that disappeared nearly two weeks ago.

The Australian Maritime Safety Authority (AMSA) described the discovery as the “best lead” investigators have in the current search for the missing Boeing 777-200ER, but urged caution until the debris is recovered.

Before that, UK commercial satellite firm Inmarsat provided the information that allowed investigators to conclude that MH370 flew for six hours longer than initially thought, pinging its satellite over the Indian Ocean up until 8.11am on March 8.

But the absence of a minor computer upgrade that would have cost the airlines US$10 (RM33) per flight prevented the satellite orbiting 38,5000 from the Earth's surface from being able to tell where MH370 was when it sent its electronic handshake, but only how far away it was.

With so-called eyes in the sky providing the best data so far on the missing flight, more such assets are being deployed to help find the plane.

China has tasked 21 satellites to help search for MH370, while NASA is contributing data from multiple scientific satellites as well as from a camera on the International Space Station.

But not all are up to the task, experts noted.

“Weather satellites can see the whole world, but can’t see anything much smaller than a hurricane,” said Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics who also runs a Web site tracking all the satellites currently in orbit.

Experts say the search is further made difficult by the fact that no one is sure what, exactly, to look for.

“It’s very hard to find something in the middle of the ocean. We don’t know the size and shape of the object we’re looking for and there’s lots of stuff in the ocean. There’s debris from shipping — containers and other stuff blown overboard. There’s natural stuff like trees and everything else,” Weeden was quoted as saying.