Galileo Galilei observed Saturn's rings and Jupiter's largest moons with something very much like a sailor's spyglass – a straight line of refracting lenses. For the average person, that's still the image of a telescope. But Isaac Newton had the idea to gather light in a parabolic mirror at the base of the telescope. It worked because the more light one pulls together, the more details come into view, and the more faint objects that might be seen. From Newton's time forward, the march of human astronomical inquiry has proceeded towards ever-larger dishes.

In space, an even broader area can be covered than could ever be achieved on Earth by constructing that "virtual dish" with probes that fly in formation. The more far-flung the receivers in the precise formation, the better the picture.

"Interferometry" means literally taking measurements from interference: interfere-meter. It works by catching light in multiple telescopes (either ground based dishes or receivers in space) and streaming it together to produce interference patterns as the light waves collide. The light waves will hit different receivers at slightly different points in their oscillations because the distance traveled is infinitesimally different. Sometimes these interactions can make light brighter, just like two water wave crests can harmonize into a larger wave if they match perfectly. In astronomy, that's called "constructive interference," but the term isn't one of value, rather it gets at the idea that these light waves are building, or constructing, something larger. In fact, if you're looking for planets, you'll want destructive interference to aid you. In interferometry, because of that tiny difference in distance traveled from star to scopes – making the light waves nearly identical but a bit out of phase – crests and troughs aren't synchronized or aligned. So the energy from one combats that of the other. The effect is that light gets canceled out, perhaps revealing a planet that was hidden in the glare.

Of course, the process rarely works so neatly though it's very predictable. Subtle differences caused by interactions between light waves, which determine colors, yield amazingly precise readings to astronomers. Astronomers have understood the phenomenon for a hundred years, and for half a century been able to use interferometers on radio waves, which are much longer than visible light waves. Optical wavelengths – those visible to the eye – are so much smaller that interferometry has been nearly impossible until recently. Indeed, even though Albert Michelson won the Nobel Prize in physics for revealing the concept of optical interferometry all the way back in 1907 (he was the first American so honored), it's only recently, with more advanced computers and sensors that astronomers could hope to truly see objects using this technique.

But applications go far beyond that one quest. Imagine a young astronomer who decides to make her career studying the development of sunspots. Despite vast amounts of data tracing solar cycles and the formation of magnetic sinusoidal whips that precede flares, there's much we don't understand about the phenomenon. One creative way to get a better grasp of these events on the face of our star would be to study how it happens on other stars.

But advocates for the emerging field of interferometry argue a number of immediately conceivable goals might be achieved by forgoing traditional deep dish astronomy.

"For missions that depend on resolution, an interferometer is better. Examples of these include thermal dust emissions from stellar dust clouds; obtaining high resolution information about faint objects outside our galaxy; detecting the precise sky position of planetary companions as small as Uranus; and characterizing the atmospheres of hot, Jupiter-sized planets separated by approximately 12 million miles from the stars they are orbiting," noted Michael Hrynevych, an interferometer optics engineer working at the Keck observatory. "By comparison, a big announcement at the AAS meeting two weeks ago centered on the detection of a stellar companion of about 60 Jupiter masses orbiting at a distance of about 1.3 billion miles from its star. This is a good feel for where current detection technology is today."