Slated for launch in 2018, NASA's James Webb Space Telescope (JWST)—the successor to the Hubble Space Telescope—is an incredible piece of hardware. Its implications for astronomy as a whole will be far-reaching and significant, and the technology behind it is significantly more advanced than any currently operational space telescope. We will be able to see things we've never seen before, and it is likely that the data it produces will change our understanding of the cosmos in profound and unexpected ways.
In a recent article, a team of U.S. and Scottish researchers suggested a particularly striking possible use for the telescope: it can be used to spot the presence of oxygen dimers on exoplanets. And oxygen dimers, as far as we know, can only be produced by living things through photosynthesis. In other words, we may very well discover life on other worlds—potentially hundreds of other worlds—within days of the JWST's launch.
The JWST can't tell us much about what kind of life we might find on these planets, or whether it's intelligent—and it will be a very long time before we're able to send physical probes out to investigate these worlds in more detail. But if the JWST discovers evidence of photosynthesis, exobiology—the study of extraterrestrial life—will become hard science.