In a move that sounds like the plot of a sci-fi novel written by a physicist with a sense of humor, NASA scientists led by Paul Stankus of Brookhaven Science Associates have proposed a new method for detecting gravitational waves at frequencies so low they make a sloth's heartbeat look frantic. The idea? Use quantum mechanical two-photon interference to measure the tiny, coordinated wiggles that passing gravitational waves cause in the apparent positions of stars.

The innovation here is that two spacecraft can operate independently, without needing to shout at each other across the void with laser links. This simplifies the whole 'building a space-based observatory' thing considerably. The target frequency range is micro-Hertz to nano-Hertz, which is currently a ghost town for gravitational wave detection. If successful, the mission could shed light on galaxy formation and supermassive black hole physics, while also giving the public something to be excited about that isn't a celebrity feud.