The search for Flight 370 “has exposed the technological limits of satellites” which can see the globe but are not designed to hone in on every section of it equally. Understandably, they concentrate their strongest attention on parts of the world other than the vast stretches of uninhabited ocean.
As for those pieces of supposed debris spotted near Australia:
“It looks to me like possibly just an exceptionally large patch of sun glint,” said John Amos, president of SkyTruth, which 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.”
Because it takes so long to thoroughly study satellite imagery over a large area, there was a gap between the time the photos were taken and the time it was decided that there might be something special in that area, even though the visual hunt was assisted by many worldwide volunteers scouring the photos.
What’s more, the search for Flight 370 has also has exposed the limits of radar. This may even be more disturbing, because radar is an old technology specifically designed (unlike satellite imaging) to detect planes that are where they shouldn’t be. That Flight 370 didn’t trigger more alarms is not a good sign, especially if it flew over land for some part of its rogue journey. Perhaps that was part of the motivation for the flight—to test the limits of radar, for future reference?