New evidence has shown that Jupiter’s icy moon Europa throws jets of water out into space.
Scientists first reported the behaviour in 2013 using the Hubble telescope, but have now made a follow-up sighting.
It is significant because Europa is one of the most likely places to find microbial life beyond Earth because of its huge ocean of liquid water.
Flying through the jets with an instrumented spacecraft would be an effective way to test the possibility.
Scientists are also looking at the possibility of attempting to capture a sample of water and bring it back to Earth for more detailed biological analysis.
The suggestion is that the jets reach several hundred kilometres in height before then falling back on to Europa.
The calculation based on the 2013-reported work estimated a volume of water equivalent to an Olympic swimming pool could be being spewed into space about every eight minutes.