Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Planetary scientist says: Focus on Europa

13.02.2007
Taking the fork in the road

Yogi Berra supposedly suggested that when you come to a fork in the road, you are supposed to take it.

That's just what planetary scientists studying the rich data set from the Galileo Mission to the outer solar system are doing now. They're taking the fork.

According to William B. McKinnon, Ph.D., professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, the community suffers from an embarrassment of riches, because each of the moons of Jupiter differs in the way that they can reveal more about planets and how they behave. But he thinks it is Europa that clearly commands the most attention.

There are four large, moons of Jupiter that in their character and behavior are more like planets than Earth's moon: Io, Europa, Ganymede and Callisto. The last three are icy.

Io's volcanic hyperactivity is well known, but there are mysteries about the temperature of its magmas and its spectacular mountains and what they might reveal about the satellite's interior processes. As for the exterior moon Callisto, how did it acquire an ocean yet not be deeply differentiated? Ganymede's liquid iron core is still generating a magnetic field. This was not predicted beforehand, and thus has much to teach planetary scientists on how magnetic fields are generated in the solar system. Then, there is Europa.

"Of the four Galilean moons, Europa is the one that has the best chance to reveal the most about the origin of life, which is the biggest unanswered scientific question we have, bar none," he said. "With its massive body of liquid water, multiple energy sources proposed and different ways to provide carbon and other biogenic elements, the central question must be Europa's potential for life. What greater question can you ask of a planet?"

McKinnon reviewed each of the moons and their unanswered questions in his invited talk, "O Sister, Where Art Thou? The Galilean Satellites After Galileo," presented at the Fall 2006 meeting of the American Geophysical Union held Dec. 10-15, 2006, in San Francisco. All but Ganymede, a young male, are named after female Greek mythological characters. Thus, McKinnon refers to Ganymede as an honorary sister.

"Europa has been recently geologically active, but because Galileo's main antenna did not unfurl, we did not take enough images to catch any active geysering, such as seen on Saturn's itsy bitsy icy moon, Enceladus," McKinnon said. "Europa's surface appears very young and there are lots of interesting ice tectonics, and surface eruptions with weird colors and spectral signatures whose compositional implications everyone just loves to argue about."

'Capped' ocean

All the accumulated evidence points to an ocean under a global shell of ice, an ocean lying no more than 10 to 20 kilometers below Europa's airless surface, McKinnon said.

"That sounds really deep to a person with a pick ax, or even a drilling rig, but in geologic terms it's really pretty close," he said. "It's basically a capped ocean. "

The existence of the ocean is related to the great amount of heat coming up from Europa's interior.

"If you look at the surface and how deformed it is, you can tell the ice shell is relatively thin and really has been active in recent geological time, indeed is probably active today," McKinnon said.

Europa has a few, but not many, impact craters, also indicating its relative youth.

Europa's ocean begs to be studied, McKinnon said, as do the strikingly colored surface materials that Galileo images captured.

"To go into orbit around Europa with high-resolution cameras, spectral imagers and sophisticated, ice-penetrating radars of the sort mapping Mars right now, would allow us to really characterize that ocean and give us clues about the biogenic potential of the surface materials, "McKinnon said. "We'd see to the bottom of the ice shell, I predict. It would be a fantastic proof of concept."

A mission to Europa is feasible, McKinnon said. It would take about 10 years if started today (six of those years being spent in reaching the satellite). And it would be expensive, "about two billion dollars, give or take," he added.

"It would also have to compete for funds with NASA's plans to establish a Moon base," he said. "The Europeans are interested as well, so maybe we could cooperate and share the cost."

NASA has committees exploring a number of options, McKinnon said, and they include returning to Europa or Titan after the conclusion of the Cassini mission or perhaps returning to the little active moon around Saturn, Enceladus.

"It's a tiny moon, but it has an active plume that, because of that moon's very low gravity, extends well out into space, so you can just fly right through it," McKinnon said. "That's a nifty way to go sampling."

Of course, Europa is a much bigger target to explore.

"It has 40 times the surface area of Enceladus — there's a lot more there there," he concluded.

Tony fitzpatrick | EurekAlert!
Further information:
http://news-info.wustl.edu/tips/page/normal/8537.html

More articles from Earth Sciences:

nachricht How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena

nachricht Canadian glaciers now major contributor to sea level change, UCI study shows
15.02.2017 | University of California - Irvine

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>