Water vapor plumes estimated to be as tall as 125 miles are possibly erupting into space from the surface of Europa, a moon around Jupiter, NASA announced on Monday.

The source of these potential plumes-- scientists haven't proven that they definitively exist yet-- is thought to be an enormous ocean beneath the icy surface of Europa, and that ocean, in turn, could possibly harbor life. (The space agency said that the ocean on Europa is massive, with two times the amount of water as Earth’s oceans.) The water vapor plumes are an exciting phenomenon for scientists, who could use them to study what’s in that ocean without having to somehow get through the ice.


“Europa’s ocean is considered to be one of the most promising places that could potentially harbor life in the solar system,” Geoff Yoder, acting associate administrator for NASA’s Science Mission Directorate in Washington, said in a statement. “These plumes, if they do indeed exist, may provide another way to sample Europa’s subsurface.”

A team of astronomers gathered the data about these possible plumes by using the Hubble Space Telescope to look at Europa while it transited in front of the gas giant it orbits. With Jupiter in the background, they looked for the plumes, and out of 10 observations, they saw the plumes three times. Their work reinforces previous research by other scientists who detected plumes that could rise as high as 100 miles off the southern surface of the moon.

Europa is not the only moon in the solar system that is thought to have water vapor plumes. Saturn’s moon Enceladus does as well—with the likely source being a global subterranean ocean— and while these latest plumes were spotted using Hubble, the jets on Enceladus were detected by the Cassini spacecraft.

In the future, NASA could send a mission to explore the possible plumes or use the next-generation space telescope, James Webb, which is due to launch in 2018.

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