MH370: Satellite imaging has come a long way

Satellites: First they helped international investigators calculate the missing Malaysia Airlines flight's last known position. Now, another one has picked up what may be debris from the vanished aircraft. But the underlying technology that made it possible? It's very different. Here's everything you wanted to know about spy and commercial satellites. Q: How good are these things, really? A: If you've used Google Earth, you know that free satellite imagery is already pretty good. Google's systems are capable of incredible resolution down to less than a meter. Some onlookers report that the real figure is actually about half a meter, and is limited only by government restrictions that prevent the image quality from getting too good. That's consistent with what Mark Lowenthal, a former intelligence official, thinks. According to Lowenthal, president of Arlington, Va.-based Intelligence and Security Academy, commercial satellite imagery can make out objects that are as small as 20 inches across. But Lowenthal notes that according to various press reports, military satellites are about twice again as good, capable of resolution down to 10 inches. Q: What did the satellites pick up off the coast of Australia? A: Investigators have identified an "object" about 79 feet across. Another is slightly smaller, about 16 feet across. It might be part of the missing plane. Q: If it was that easy, why didn't we see this stuff sooner? A: Hang on. The objects are pretty big, but the ocean they were floating in was much, much bigger. This is where imagery analysis comes into play. In industry lingo, it's called geospatial intelligence, or GEOINT. "Over time, [analysts] learn to look for patterns," Lowenthal said in an interview. "They look for patterns and anomalies. They're looking at a dark background and for objects that don't belong there." If that sounds easy, it's not. It calls for special training . You can actually get a degree in GEOINT from places like Penn State University. Q: How far has satellite imaging come? I can't imagine we're still doing it like we did in the Cold War. A: Well, the basic idea has mostly remained unchanged you take pictures of the ground and have really smart people comb through them for interesting things. But yes, technology has dramatically improved how we gather, retrieve and interpret GEOINT. In the early days, we used to send planes with cameras to do aerial reconnaissance. That became really common during World War II. Eventually, we graduated to high-altitude spy planes like the U-2 and SR-71. In 1960, the United States launched a program known as Corona. The satellites under that program were code-named Key Hole. They looked like a long, thin cigar and carried film in a huge titanium canister according to Lowenthal, it was about the size of a large medicine ball.

Image of the object believed to be related to the missing MH370 aircraft, captured by satellite