Posted on 03/15/2007 1:15:17 PM PDT by Jedi Master Pikachu
By Paul Rincon
Interest in Europa has been fuelled by indications that a liquid water ocean lurks beneath its outer shell of ice. The mapping effort will help build a geological history of the enigmatic moon and target future explorations. A team at Arizona State University compiled the maps from data sent back by the US-European Galileo probe. Galileo explored the Jupiter system from 1995 to 2003.
The work was presented here at the Lunar and Planetary Science Conference in Houston. The maps have allowed the scientists to identify several distinct geological units on Europa. Understanding the distribution and age relationships of these units can assist the reconstruction of a geological history for the moon. Europa's surface is young, active and smooth with few craters. But it is criss-crossed by a network of fractures, thought to be where the icy shell has been prised apart by the tidal forces of Jupiter.
"When we make planetary maps, we're pretty limited by fieldwork, so 'ground truth-ing' is difficult - but not impossible, as we've found with the Mars Rovers," said Professor Ron Greeley, director of planetary geology at Arizona State University (ASU) in Tempe, US. "We have to rely on remote sensing information. On Earth, this is conventionally done in exploration for oil or mineral deposits. The data is used to make maps to figure out the best places to go and explore. "That's what we're doing with Europa. We're trying to figure out what's what on the surface so we can go and explore further." Salty ocean Voyager 2, launched in 1977, was the first spacecraft to fly past Europa, sending back snatched glimpses of the surface at a resolution of about 2km (1.2 miles) per pixel. Galileo made multiple flybys of the moon, building up a collection of images at different resolutions, ranging from 12.6 to 0.23km (7.8-0.14 miles) per pixel.
Compiling these pictures into a global map has required painstaking work by Ron Greeley, Thomas Doggett and their colleagues at ASU. "We do not have global coverage, even at the lowest resolution. It is very non-uniform. Also, the illumination of the surface differs widely from one dataset to another," explained Professor Greeley. Europa, the fourth largest of Jupiter's satellites, is a high priority for future exploration. Study of its magnetic field by the Galileo probe provided strong evidence for a salty ocean beneath the ice.
The moon contains all the ingredients needed for the emergence of life: liquid water, an energy source (provided by the tidal pull exerted by Jupiter's gravity) and organic chemicals. If life ever emerged on Europa, researchers believe it could exist in an environment similar to terrestrial deep ocean hydrothermal vents or Antarctica's Lake Vostok. Mission proposals Nasa has drawn up science definition teams to assess four potential targets for a "flagship" robotic mission to launch after 2015. These targets are the Jupiter system, Europa and Saturn's moons Enceladus and Titan. The agency has appointed Ron Greeley and Robert Pappalardo from Nasa's Jet Propulsion Laboratory in California to co-chair a team of about a dozen experts who will set out the major science objectives for a Europa mission.
Their work will look at what instruments a spacecraft should take, what orbits would be required for the mission and how the probe might operate in the Jovian moon's harsh radiation environment. After the four teams report back in the summer, officials at Nasa HQ in Washington DC will evaluate the case for a mission and decide which to carry forward. In addition, an international consortium is preparing a Europa mission proposal to be submitted under the European Space Agency's (Esa) Cosmic Visions programme of space exploration. This consortium is exploring a potential link-up with Japanese partners. A "dream" concept for the exploration of Europa would be a robotic probe, perhaps powered by radioactive decay, that could melt through the ice and explore the ocean beneath. But this would pose formidable technical challenges: the ice shell could be about 20km (12 miles) thick, according to one model. "Is the technology there to do that? Possibly. My own personal feeling is that it is fantastically ambitious," said Professor John Zarnecki, from the UK's Open University, who is a member of the consortium hoping to mount a European mission to the Jovian moon. "I think there should be a two-stage approach, beginning with an orbiter, perhaps with ground-penetrating radar and perhaps a way of measuring the gravity field - which is another way to tell what's beneath the surface. Then we go for a lander and a penetrator." Just getting to Europa is tough, a spacecraft would have to pick up lots of speed and then break hard to reach it. In addition, the harsh radiation environment gives a spacecraft orbiting the moon a lifetime of just 66 days, according to an Esa feasibility study. Paul.Rincon-INTERNET@bbc.co.uk
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Representatives of NAMBLA have volunteered to be the first survey party.......
"All these worlds are yours except Europa. Attempt no landing there."
What possible interest could the North American Marlon Brando Look Alikes have in Europa?
Arthur Clarke would be happy
That, and the going on and on and on and on and on about Macroevolutionism in the first book (granted, that is a big part of the series--some aliens influencing the Macroevolution of Man--and Europans).
Sometimes I dream of working on another really big project like bringing water from Europa to Mars and the moon, and bringing hydrocarbon from Titan to Mars and the moon and then building permanent towns both places. Funny thing, this is for the future although it could have been started 30 years ago.
Yup, some 60 years from the Wright brothers first flight to a moon landing and next to nothing (manned) in the 40 years since.
I like to listen to Richard C Hoagland because he has an elegant conspiracy story to explain why NASA hasn't gone back to the moon or on to Mars. But, all that will go by the boards when China starts moving, and they will move into outer space before we do. We like to say that China is 40 years behind the USA in outer space exploration, and so they are, but so are we.
According to Hoagland the government doesn't want us peons to find out the moon is littered with C3PO heads.
That is what he says. I wonder if the Chinese will play along with this scam.
I'll offer another standing bet to all takers: I bet $100 that we find at least microbes in the ocean on Europa. Panspermia rules!
Manned landings on the moon are a myth. It was all filmed in the Nevada desert under the direction of ET, Bigfoot and the Loch Ness Monster. /tinfoil
Icy moon you say? I thought that was Bill Clinton's pet name for Hillary.
Killer kudzu on Europa.
[stealing from Will Rogers] We should pick up Europa, and move it. ;')
Europe tells US: 'Come to Europa'
BBC | 3/14/05 | Jonathan Amos
Posted on 03/15/2005 12:57:34 AM EST by LibWhacker
http://www.freerepublic.com/focus/f-news/1362945/posts
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