Scientists at the California Institute of Technology recently announced that they have evidence of water on Saturn’s tiny moon Enceladus. And not only is there water, it is probably liquid water.
How can this be possible on an object that is almost 900 million miles away from the Sun (about 10 times the Earth-Sun distance) and has a temperature of – 201 degrees Celsius (-330 degrees F) ? The answer has to to with gravity. Enceladus is small – its diameter is only 310 miles – and it is caught in a gravitational battle between massive Saturn and the moon Dione. This basically warps the surface of Enceladus, producing enough heat to liquify the water in its center. Enceladus is not unique in this regard, scientists have long suspected that there is water on Jupiter’s moon Europa, and that it is liquid water due to the gravitational tug-of-war between Europe and Jupiter.
Since 2005 scientists have know about the possibility of water on Enceladus when they discovered plumes of ice coming from the southern surface of the planet. Within the ice were molecules of carbon dioxide and methane. Carbon compounds, and energy source, and liquid water are the prime ingredients for life.
So how much water is there? Remember that Enceladus is small – but the initial research suggests that there is a sea about the size of Lake Superior located in the southern hemisphere. This sea is located between an ice covering (about 20 miles thick) and the rocky core of the planet (see the artist rendition below). It is estimated that this sea may be about 6 miles deep, providing plenty of water for the evolution of life.
Why is Water Important?
Water has a special relationship with life. It is an excellent solvent, it is both cohesive and adhesive, and it regulates changes in temperature. In fact, we haven’t found any evidence of life yet on Earth that isn’t based on water. While that does not mean that there aren’t examples out there somewhere in the Universe, it does allow us a starting point with which to begin our search for life outside of Earth.
For a quick review, here is our video on the properties of water:
So what is next? While we are actively searching Mars for signs of life that most likely went extinct millions of years ago, there is a possibility that life, or maybe just he early forms of life, may be underneath the ice at Enceladus. Seems like that warrants a look.
- “The three best places in the solar system to look for life (other than Mars)” – The Meridiani Journal (May 28, 2013)
- “Under Icy Surface of a Saturn Moon Lies a Sea of Water, Scientists Say” NYTimes (April 3, 2014)
- “Saturn Moon Has Geysers, Hinting Life Is a Possibility” NY Times (March 10, 2006)
- RicochetScience article – Properties of Water
- Iess L., Stevenson D.J., Parisi M., Hemingway D., Jacobson R.A., Lunine J.I., Nimmo F., Armstrong J.W., Asmar S.W. & Ducci M. & (2014). The Gravity Field and Interior Structure of Enceladus, Science, 344 (6179) 78-80. DOI: 10.1126/science.1250551