The search for habitability elsewhere in the universe can arguably be reduced to the search for water. We haven't yet found lifeforms that detach this substance from our conception of "life" itself, so we have no choice but to accept the cosmic water trail as our north star in the quest to find worlds that mirror our own.
It is for this reason that scientists jump for joy a little when they find an exoplanet likely to hold any water at all — but particularly liquid water, rather than ice or water vapor. And I'd hope at least one astronomer gleefully hopped somewhere recently, as a team of researchers just announced that a tantalizing planet outside the solar system may have a temperate water ocean about half the size of the Atlantic. Better yet, the find is thanks to the James Webb Space Telescope.
