Jupiter's Moon Europa May Spew Water Jets Into Space: NASA

A composite image shows suspected plumes of water vapor erupting at the seven o’clock position off the limb of Jupiter’s moon Europa in a NASA Hubble Space Telescope picture taken January 26, 2014 and released September 26, 2016. The apparent plumes could be tested for signs of life. NASA/ESA/W. Sparks (STScI)/USGS Astrogeology Science Center/Handout via Reuters

Scientists have discovered further evidence that Europa, the icy moon of Jupiter, shoots jets of water into space.

Researchers used the Hubble telescope to first observe the plumes in 2013, but a follow-up sighting announced by NASA on Monday raises the possibility of testing material ejected from Europa for elements required for life.

Europa, which is roughly the size of Earth's moon, has a huge subsurface ocean of liquid water. If the apparent plumes do not exist, the only way to test Europa for signs of microbial life would be to try and land on the moon and drill through miles of solid ice.

The possibility of plumes of ejected material means that scientists could fly an instrumented spacecraft through the jets, and potentially even capture a sample of the ejected material, to analyze its composition.

Researchers observed the apparent plumes by studying Europa as it passed in front of Jupiter, which provided a backlight behind the moon. The team used the Hubble telescope to look in ultraviolet wavelengths to see if the planet's light was being absorbed by material emanating from the moon's surface.

On three of the 10 occasions they studied Europa, the researches saw what looked like "dark fingers" extending from the edge of the moon. The study's lead astronomer, William Sparks, said that water plumes seemed the most likely explanation for the protuberances, but said that the researchers remained wary. "We do not claim to have proven the existence of plumes, but rather to have contributed evidence that such activity may be present," said Sparks, according to the BBC.

While the presence of such jets does not in any way confirm the possibility of life on Europa, it does further mark out the icy moon—with a temperature which reaches only around -160 degress Celsius (-260 degrees Fahrenheit) at its warmest—as a candidate for further study, according to Paul Hertz, director of astrophysics at NASA.

"On Earth, life is found wherever there is energy, water and nutrients. So we have a special interest in any place that might possess those characteristics. And Europa might be such a place," said Hertz.