Less than a month after scientists discovered liquid methane waves on the Saturn moon of Titan, researchers, using NASA's Cassini spacecraft, have now discovered a body of liquid water under the icy surface of Saturn's other moon Enceladus.

The recent discovery on Saturn's sixth-largest moon was published in the journal Science.

The moon has been closely observed since 2005 when scientists caught Enceladus squirting plumes of mineral-rich water near its south pole, the Los Angeles Times reported.

The 2005 discovery lead most scientists to believe that water existed on the planet and so could the possibility of life because they found traces of sodium and potassium salts along with ammonia and methane in the water vapor plume.

Enceladus is only 313 miles across and is primarily frozen, but scientists said that because the moon is in a constant tug-of-war with the Saturn and its other moon Dione, the tidal distortions heats up the moon and melts some of the water ice under the surface.

To make the discovery, scientists had to measure different gravitational spots around the moon using the Doppler affect with Cassini. As the spacecraft orbited the moon several times, a signal was sent out when it wobbled as a response to being squeezed and stretched by the gravitational pull.

Denser surfaces meant there was a stronger gravitational tug while less dense areas indicated a weaker gravitational pull, according to the Times.

The researchers initially theorized that the dent in the moon's south-pole area would produce less gravitational pull, but they noticed the tug got stronger when Cassini flew over it, meaning there is something dense underneath.

David Stevenson, a Caltech planetary scientist and coauthor of the study, told the Times that it has to be water underneath because it's the only logical explanation.

"There's no other reasonable candidate," Stevenson said. "There is rock down there, but it gives the wrong signal."

The shell of ice around Enceladus is about 25 miles thick, scientists say, with the sea of water underneath and about six miles deep. Based on Cassini's gravitational data, scientists also believe the water reservoir could be about the size of Lake Superior and could even reach up into its north pole.