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Title: Is Jupiter's Bizarre Moon Our Best Hope for Finding Extraterrestrial Life?
Post by: SETI on August 30, 2009, 06:10:05 pm

Space / Extraterrestrial Life
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Is Jupiter's Bizarre Moon Our Best Hope for Finding Extraterrestrial Life?

NASA is gambling $4 billion that there's life beneath the thin atmosphere, lethal radiation, and miles-thick ice on Europa.
by Andrew Lawler

From the September 2009 issue, published online August 28, 2009

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The Science Channel show Brink recently produced a segment based on this DISCOVER story; see the video below.

Title: Re: Is Jupiter's Bizarre Moon Our Best Hope for Finding Extraterrestrial Life?
Post by: SETI on August 30, 2009, 06:11:24 pm
The crackling radiation would kill you in 10 minutes—that is, if you did not first asphyxiate in the nearly nonexistent atmosphere, die of exposure to the –300 degree Fahrenheit temperature, or plunge into a thousand-foot-deep icy crevice. Jupiter’s moon Europa is a forbidding world, yet NASA intends to devote billions of dollars over the next decade to getting there. At the center of this effort will be the most complicated orbital explorer ever built, each of its components carefully armored against the deadly stream of particles in Jupiter’s massive wake. The orbiter will require six years to reach its destination. Then, when it arrives at Europa, engineers will consider the mission successful if it survives for just three months of exploration before shorting out.

This seemingly quixotic effort was conceived by a small but tenacious group of planetary researchers who, after years of trying, convinced budget-strained NASA officials this past February that the wildly expensive venture is a worthwhile, even crucial, investment. They succeeded because Europa—1,940 miles wide, just slightly smaller than Earth’s moon—is such an enticing paradox. Beneath its tortured, icy, and hostile surface lies a vast buried ocean, a warm global sea with perhaps a larger volume than all the water on Earth. And with liquid water comes one of the most intriguing possibilities in all of science: extraterrestrial life.

Title: Re: Is Jupiter's Bizarre Moon Our Best Hope for Finding Extraterrestrial Life?
Post by: SETI on August 30, 2009, 06:11:55 pm
“I believe that Europa is the most promising place in the solar system for astrobiological potential,” says Robert Pappalardo, a planetary scientist at the NASA Jet Propulsion Laboratory (JPL) in Pasadena, who is set to take the role of study scientist for the Europa mission.

Through much of the past century, Mars was regarded as the only plausible place in the solar system where alien life could exist. But a dozen costly American missions have provided no solid evidence that organisms ever inhabited the Red Planet. There is not even any clear sign of liquid water there today, only intriguing hints of lakes and rivers that apparently dried up millions of years ago. That is a big reason why scientists are increasingly pinning their hopes on Europa, a world that is literally swimming in water. In February NASA and the European Space Agency (ESA) agreed to turn their gaze away from Mars and focus on Europa and the other massive satellites of Jupiter—a grouping that includes the largest moon and several exotic ocean worlds right out of science fiction, all circling the largest planet in the solar system.

The upcoming operation—currently known by its bureaucratic program name, the Europa Jupiter System Mission—heralds a new era for exploring the outer solar system. Almost everything we know about that vast realm comes from quick flybys provided by Pioneer and Voyager and broad surveys conducted by two probes, Galileo (which examined Jupiter and its moons before taking a planned suicide plunge into the giant planet in 2003) and Cassini (which is still bouncing around the Saturn system). If all goes as planned, that situation will begin to change in 2020, when a huge NASA spacecraft will set out for Europa. Soon after, ESA will launch a companion probe to Ganymede, one of Jupiter’s other giant, icy moons. Both vehicles would slide into the Jupiter system by 2026, spend a year or two touring the planet and its satellites, then settle into orbit around their respective targets.

The 9,000-pound NASA probe will bristle with a dozen specialized instruments designed to see, smell, and explore Europa from a choice vantage point 60 miles away. Its powerful radar will penetrate the surface remotely, perhaps peering all the way through Europa’s icy shell and into the ocean beneath, while other instruments make detailed maps of the fractured landscape, analyze the molecules that make up Europa’s fantastically tenuous atmosphere, and measure the radiation effects of formidable Jupiter, which dominates the moon’s sky with its pink- and salmon-colored cloud bands and swirling red storm.

Title: Re: Is Jupiter's Bizarre Moon Our Best Hope for Finding Extraterrestrial Life?
Post by: SETI on August 30, 2009, 06:12:20 pm
One of the first orders of business will be to unravel the perplexing mysteries of Europa’s unique topography. It is one of the most geologically bizarre and active? places in the solar system. Unusual cracks—some concentric and resembling spider webs, others forming chains of conjoined arcs—commingle with odd clusters of bowl-shaped craters, strangely configured plateaus, terrain aptly dubbed chaoses, and 2,000-mile-long cracks as straight as Midwest highways. But it is the underlying ocean (and its potential for harboring life) that has sparked the most interest, as well as an unusually bitter debate within the tight-knit and typically collegial field of planetary science. If Europa’s surface is thin and porous like an Arctic ice sheet (as a few vocal researchers assert), then a rich soup of organic chemicals and oxygen from the radiation-soaked surface may have percolated down, seeding the underlying ocean with the essential building blocks of life. But if the shell is thick (most scientists suspect it averages 10 miles or more), there is little chance for contact between surface and sea, and the prospect for living organisms is far smaller.

To most researchers the nature of the ice determines whether Europa really is a plausible home for alien life. Bluntly put, the ice could be either a protective canopy or a killing lid, and the Europa Jupiter System Mission aims to figure out which. “Thick ice does mean it’s harder for life,” Pappalardo says. Then he hedges a bit: “It certainly doesn’t rule it out.” Even if the ice is thick, there may be ways life could have originated and persisted on Europa. For instance, an active, churning mantle below the sea might bubble up heat and chemicals that could serve as the basis for biology. “We don’t know yet how thick the ice is, but I think the surface tells us there’s an interesting geology there,” says Ron Greeley, a planetary geologist at Arizona State University who cochairs Europa’s science definition team.

Patience is a necessity rather than a virtue among planetary scientists. Seeing a mission through from conception to fruition can consume much of a researcher’s career. When Pappalardo began to push for a Europa mission a decade ago, there was no gray in his long ponytail. And even if all goes smoothly, the lanky 45-year-old will be close to retirement age when the first results from Europa traverse the millions of miles between Jupiter and Earth. Time is even more of the essence for Greeley, who by then will be pushing 90. “We do these things not just for ourselves but for our students and their students,” he says. In fact, one of his former students is Pappalardo.

Title: Re: Is Jupiter's Bizarre Moon Our Best Hope for Finding Extraterrestrial Life?
Post by: SETI on August 30, 2009, 06:12:56 pm
NASA’s flagship missions, such as the Hubble Space Telescope or the Cassini probe, are few and far between, and they require years of quiet, behind-the-scenes negotiation before the first component is manufactured. Researchers typically must first agree on a priority, which can entail long cycles of meetings, correspondence, and presentations and often involve a competition. NASA must then win White House approval for such major missions and convince Congress to provide funding. The Europa mission is projected to cost nearly $4 billion, making it by far the most expensive robotic mission in history (in current dollars, at least).

Even by the standards of this slow-motion field of science, Europa’s advocates have been remarkably tenacious. Three times in the past 15 years they put forward proposals, only to see their hopes dashed. At first, even Pappalardo was unconvinced that Europa had a buried ocean, much less one that could support life. “I was a skeptic,” he recalls. Since there is no way to see through Europa’s surface ice, all evidence of an ocean lying beneath it was circumstantial. Pappalardo published a 1999 paper questioning the evaluations by his colleagues of a liquid sea. But newer analyses based on Galileo’s flybys in the late 1990s and early 2000s made him change his tune. Once he became convinced the water was there, he started pushing much harder for a dedicated mission to go back to Europa and find out for sure.

Title: Re: Is Jupiter's Bizarre Moon Our Best Hope for Finding Extraterrestrial Life?
Post by: Volitzer on August 30, 2009, 10:09:40 pm
Just go to the moon or Venus and you'll see plenty of humans there.

Title: Re: Is Jupiter's Bizarre Moon Our Best Hope for Finding Extraterrestrial Life?
Post by: Fight the Future on August 31, 2009, 03:01:32 am
I've heard of an advanced civilization on the moon, but Venus?  Do you have a link for that?

Title: Re: Is Jupiter's Bizarre Moon Our Best Hope for Finding Extraterrestrial Life?
Post by: Volitzer on September 01, 2009, 02:10:24 am