In our solar system, Earth is one of but eight planets – nine, if you really want to count Pluto – and the only one remotely hospitable to life. But look beyond our sun's gravitational pull into the ...

Just decades after the first exoplanets were identified, our database of the distant worlds—monitored by the NASA Exoplanet Science Institute—has breached a new threshold. Now, astronomers have ...

Since astronomers found the first planets outside our solar system in 1992 and the first planet around a sunlike star in 1995, scientists have sought the telltale glimmers, flickers and wobbles that ...

Scientists are unraveling the mysteries of "steam worlds"—exoplanets known as sub-Neptunes that are rich in water but orbit so close to their stars that their surfaces are shrouded in thick ...