Astronomers have discovered more than 300 planets that orbit stars other than our sun. Most of these are gas giants like Jupiter. Powerful new space telescopes will make it easier to spot much smaller rocky extrasolar planets that are more similar to Earth. A team of astronomers and astrobiologists has devised a technique to tell whether these planets have liquid water. This could tell whether it might be able to support life.

It will be years before the launch of space telescopes capable of making similar observations for Earth-sized exoplanets. Creating this technique now could guide the construction of those instruments, however. These planets will be much farther away but the techniques will be similar. Imagine the bathroom faucets! ha!