The Milky Way is teeming with billions of planets, including many that are similar to our own. But how many of these alien worlds have water, and do any host extraterrestrial life?
No answers to those questions just yet. But astronomers using a new infrared technique say they've discovered water vapor in the atmosphere of a nearby gas giant planet called "tau Boötis b."
The finding suggests that the technique may play an important role in identifying which exoplanets might be hospitable for life.