Super-Sensitive Electronic Ears For Extremely Faint Signals from Space
By the time transmissions from a distant spacecraft reach Earth, they've become degraded, to the point where a signal may actually contain less than a photon worth of energy [source: Rambo]. And that's really, really weak. Remember that photons, the tiny massless particles that are the smallest unit of energy, are incredibly tiny; a typical cell phone emits 10 to the 24th power worth of photons every second [source: University of Illinois]. Picking out that mind-bogglingly faint signal from the irrepressible cacophony of space and making sense of it might be as difficult as, say, finding a message floating in a bottle somewhere in the Earth's oceans. But researchers have come up with an intriguing solution, according to the NASA's Space Technology Program Web site, which underwrites that sort of problem solving.
Instead of sending out a single signal or pulse of energy, a spaceship trying to communicate with Earth would send out many copies of that signal, all at once. When the weakened signals got to Earth, mission control would use a device called a structured optical receiver, or Guha receiver (after the scientist, Saikat Guha, who invented the concept), to essentially reassemble the surviving tiny, weak bits and pieces of all those duplicate signals, and put them together to reconstruct the message [sources: Rambo, Guha]. Imagine it this way: Take a message typed on a piece of paper, and then print a thousand copies of it, and run them all through a shredder and then mix up the tiny pieces that result. Even if you throw most of those little pieces into the trash, the ones that remain might well give you enough information to reconstruct the message on the paper.