Surprise methanol detection points to an evolving story of Enceladus's plumes

July 04, 2017

A serendipitous detection of the organic molecule methanol around an intriguing moon of Saturn suggests that material spewed from Enceladus undertakes a complex chemical journey once vented into space. This is the first time that a molecule from Enceladus has been detected with a ground-based telescope. Dr Emily Drabek-Maunder, of Cardiff University, will present the results on Tuesday 4th July at the National Astronomy Meeting at the University of Hull.

Enceladus's plumes are thought to originate in water escaping from a subsurface ocean through cracks in the moon's icy surface. Eventually these plumes feed into Saturn's second-outermost ring, the E-ring.

Drabek-Maunder says: "Recent discoveries that icy moons in our outer Solar System could host oceans of liquid water and ingredients for life have sparked exciting possibilities for their habitability. But in this case, our findings suggest that that methanol is being created by further chemical reactions once the plume is ejected into space, making it unlikely it is an indication for life on Enceladus."

Past studies of Enceladus have involved the NASA/ESA Cassini spacecraft, which has detected molecules like methanol by directly flying into the plumes. Recent work has found similar amounts of methanol in Earth's oceans and Enceladus's plumes.

In this study, Dr Jane Greaves of Cardiff University and Dr Helen Fraser of the Open University detected the bright methanol signature using the IRAM 30-metre radio telescope in the Spanish Sierra Nevada.

"This observation was very surprising since it was not the main molecule we were originally looking for in Enceladus's plumes," says Greaves.

The team suggests the unexpectedly large quantity of methanol may have two possible origins: either a cloud of gas expelled from Enceladus has been trapped by Saturn's magnetic field, or gas has spread further out into Saturn's E-ring. In either case, the methanol has been greatly enhanced compared to detections in the plumes.

Team member Dr Dave Clements of Imperial College, points out: "Observations aren't always straightforward. To interpret our results, we needed the wealth of information Cassini gave us about Enceladus's environment. This study suggests a degree of caution needs to be taken when reporting on the presence of molecules that could be interpreted as evidence for life."

Cassini will end its journey later this year, leaving remote observations through ground- and space-based telescopes as the only possibility for exploring Saturn and its moons - at least for now.

Drabek-Maunder adds: "This finding shows that detections of molecules at Enceladus are possible using ground-based facilities. However, to understand the complex chemistry in these subsurface oceans, we will need further direct observations by future spacecraft flying through Enceladus's plumes."
-end-


Royal Astronomical Society

Related Saturn Articles from Brightsurf:

Where were Jupiter and Saturn born?
New work reveals the likely original locations of Saturn and Jupiter.

Hubble sees summertime on Saturn
Saturn is truly the lord of the rings in this latest snapshot from NASA's Hubble Space Telescope, taken on July 4, 2020, when the opulent giant world was 839 million miles from Earth.

Discovered a multilayer haze system on Saturn's Hexagon
The most extensive system of haze layers ever observed in the solar system have been discovered and characterised on the planet Saturn.

What makes Saturn's atmosphere so hot
New analysis of data from NASA's Cassini spacecraft found that electric currents, triggered by interactions between solar winds and charged particles from Saturn's moons, spark the auroras and heat the planet's upper atmosphere.

New SwRI models reveal inner complexity of Saturn moon
A Southwest Research Institute team developed a new geochemical model that reveals that carbon dioxide (CO2) from within Enceladus, an ocean-harboring moon of Saturn, may be controlled by chemical reactions at its seafloor.

Saturn surpasses Jupiter after the discovery of 20 new moons
Move over Jupiter; Saturn is the new moon king. A team led by Carnegie's Scott S.

New SwRI study argues that Saturn's rings are actually not young
No one knows for certain when Saturn's iconic rings formed, but a new study co-authored by a Southwest Research Institute scientist suggests that they are much older than some scientists think.

Hubble reveals latest portrait of Saturn
The NASA/ESA Hubble Space Telescope's Wide Field Camera 3 observed Saturn on 20 June 2019 as the planet made its closest approach to Earth this year, at approximately 1.36 billion kilometres away.

Saturn's rings shine in Hubble's latest portrait
Saturn is so beautiful that astronomers cannot resist using the Hubble Space Telescope to take yearly snapshots of the ringed world when it is at its closest distance to Earth.

Saturn's moon Mimas, a snowplough in the planet's rings
The Solar System's second largest planet both in mass and size, Saturn is best known for its rings.

Read More: Saturn News and Saturn Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.