Evidence for ocean on Enceladus: Tiny Saturn Moon Could Be Targeted in Search for Extraterrestrial Life

Jul 22, 2009 By Lori Stiles
Tiny Saturn Moon Could Be Targeted in Search for Extraterrestrial Life
Cassini imaging scientists used views like this one to help them identify the source locations for individual jets spurting ice particles, water vapor and trace organic compounds from the surface of Saturn's moon Enceladus. This false-color view was created by combining three clear filter images taken at nearly the same time. (NASA/JPL/Space Science Institute)

(PhysOrg.com) -- Plumes spewing from a tiny moon of Saturn - a moon roughly the width of Arizona - are filled with molecules that suggest that the moon, Enceladus, is likely another place in the solar system to look for life, Cassini scientist Jonathan Lunine of The University of Arizona Lunar and Planetary Laboratory said.

When NASA's flew through a plume erupting from Enceladus early last October, its Ion and Neutral instrument measured ammonia, 40 and an abundance of carbon-bearing molecules, or "organics," entrained in the .

Lunine is on the team reporting the results in the July 23 issue of the journal Nature.

Cassini discovered water vapor and particles spewing from Enceladus in a previous, more distant flyby in 2005. Since then, scientists have been trying to determine if the source of the jets is liquid.

"The fact that there's ammonia on Enceladus is important because it argues the plumes are erupting from a region of liquid water beneath the surface of Enceladus, rather than erupting from what is just warm ice," Lunine said.

Ammonia acts as antifreeze. Water containing ammonia remains liquid at temperatures as low as minus 143 degrees Fahrenheit.

Cassini has measured temperatures higher than minus 136 degrees Fahrenheit near the fractures where Enceladus shoots out its water vapor plumes, so "We think we have an excellent argument for a liquid water interior," said Hunter Waite of the Southwest Research Institute in San Antonio, Texas, lead scientist for Cassini's Ion and Neutral Mass Spectrometer experiment.

Argon 40, an isotope of argon, which is a decay product of potassium, also strengthens the argument for a liquid water source, Lunine said. Rocks on Earth and elsewhere, including Saturn's giant , give off argon 40.

"The fact that we found a lot of argon 40 also argues for liquid water," Lunine said. most likely circulating through Enceladus' rocky core is the best explanation for all the argon 40 detected, he said.

The Cassini team also discovered such carbon-bearing molecules as methane, formaldehyde, ethanol and hydrocarbons are plentiful in the plumes.

Given other recently reported Cassini evidence for sodium and potassium in Saturn's E ring - a ring made of material that comes from Enceladus, there must be a salty, liquid layer in Enceladus that "seems like a pretty good environment for life," Lunine said.

"What I think is really interesting now is that we have four places in the outer solar system with interior oceans," he said.

Scientists have evidence that Saturn's Titan and Jupiter's moons Europa and Ganymede also have oceans.

Mars, Titan, Europa and now seem to be good sites to search for extraterrestrial life, Lunine added.

Provided by University of Arizona (news : web)

Explore further: The source of the sky's X-ray glow

add to favorites email to friend print save as pdf

Related Stories

Cassini Tastes Organic Material at Saturn's Geyser Moon

Mar 26, 2008

NASA's Cassini spacecraft tasted and sampled a surprising organic brew erupting in geyser-like fashion from Saturn's moon Enceladus during a close flyby on March 12. Scientists are amazed that this tiny moon ...

Tiny Enceladus May Hold Ingredients of Life

Sep 05, 2005

Saturn's tiny moon Enceladus is "absolutely a highlight" of the Cassini mission and should be targeted in future searches for life, Robert H. Brown of The University of Arizona, leader of the Cassini visual ...

Recommended for you

The source of the sky's X-ray glow

15 hours ago

In findings that help astrophysicists understand our corner of the galaxy, an international research team has shown that the soft X-ray glow blanketing the sky comes from both inside and outside the solar system.

End dawns for Europe's space cargo delivery role

Jul 27, 2014

Europe will close an important chapter in its space flight history Tuesday, launching the fifth and final robot ship it had pledged for lifeline deliveries to the International Space Station.

Giant crater in Russia's far north sparks mystery

Jul 26, 2014

A vast crater discovered in a remote region of Siberia known to locals as "the end of the world" is causing a sensation in Russia, with a group of scientists being sent to investigate.

NASA Mars spacecraft prepare for close comet flyby

Jul 26, 2014

NASA is taking steps to protect its Mars orbiters, while preserving opportunities to gather valuable scientific data, as Comet C/2013 A1 Siding Spring heads toward a close flyby of Mars on Oct. 19.

Bacteria manipulate salt to build shelters to hibernate

Jul 25, 2014

For the first time, Spanish researchers have detected an unknown interaction between microorganisms and salt. When Escherichia coli cells are introduced into a droplet of salt water and is left to dry, b ...

How do we terraform Venus?

Jul 25, 2014

It might be possible to terraform Venus some day, when our technology gets good enough. The challenges for Venus are totally different than for Mars. How will we need to fix Venus?

User comments : 8

Adjust slider to filter visible comments by rank

Display comments: newest first

deatopmg
2.8 / 5 (9) Jul 22, 2009
NASA won't even send life detection equipment to Mars after detection of life (or some unknown magical chemical process, aka; life)by Viking 35 yrs ago. Why would they send it to Enceladus other than obfuscation??
omatumr
2.3 / 5 (6) Jul 22, 2009
TOO COLD FOR LIFE ON ENCELADUS

I agree with deatopmg.

Of course there are lots of organics in the outer part of the solar system because that region consists mostly of H, He, C, and N - lightweight elements from the outer layers of the supernova that gave birth to the solar system.

But life as we know it cannot be sustained without a daily dose of energy from the Sun to drive the chemical reactions of life.

Since solar radiation falls off rapidly with distance from the Sun, the search for evidence of life on Enceladus may be nothing more than wishful thinking.

With kind regards,
Oliver K. Manuel

PinkElephant
4.8 / 5 (5) Jul 22, 2009
But life as we know it cannot be sustained without a daily dose of energy from the Sun to drive the chemical reactions of life.


Some of us also happen to know life that never sees the sun, and has absolutely no need for it. Reference communities of organisms around black smokers in oceanic rifts, and other extremophiles extracting chemical energy from rock, miles underground.
eric96
4.2 / 5 (6) Jul 23, 2009
The Sun is not the only source of heat, but of course the average folk think it is. The surface temperatures measured on this moon and titan are both abnormally high when you consider how many photons reach them not including the fact that they may have small atmospheres deflecting some of that back, yet surface temperatures are higher than normal. The explanation althought not 100% verified is that there is either a liquid or tectonic core in which the friction caused by the gravity of the moons planet is really shaking things up in there like a microwave such that certain internal parts may be warm enough to harbor life, and a warmer interior explains the higher than expected surface temperatures. Oh! and did you know certain extremophiles such as tardigrade ("small bear") can survice in space for a respectable amount of time ( I believe days) despite flunctuating -200c to 250c not mentioning the massive radiation.
docknowledge
3.8 / 5 (5) Jul 23, 2009
deatopmq, if finding life was as easy as walking up to a three-legged alien and seeing if it moved, NASA would have done it a long time ago.

But we've known for decades that Mars has almost no atmosphere, very cold temperatures, no obvious plant life, horrendous sandstorms that frequently cover much of the planet. NASA isn't looking for big aliens wearing beanie caps, they are looking for very small, very limited life that might take any of several forms.

There's no simple easy way to test. Which is pretty apparent when considering that until just a few years ago, hundreds of years of scientists missed the life on the smokers that PinkElephant mentions.
out7x
1 / 5 (1) Jul 23, 2009
How does a plume of water suddenly become an underground ocean? Anyone hear of porous rock with fracture permeability under high heat pressures?
docknowledge
not rated yet Jul 23, 2009
out7x, sorry I don't have the URL, but there's a very interesting paper out which graphically shows the difference between the four prevailing theories. If I remember, your idea is among them.
chaman
not rated yet Jul 24, 2009
Scientists at the University of Colorado at Boulder, recently said that "Water vapor jets that spew from the surface of Saturn's icy moon Enceladus are not really geysers from an underground ocean as initially envisioned by planetary scientists". (June 2009).
(http://www.physor...4.html).

You can't believe anyone these days.