Europa discussion

[John Sheff]

Here’s an example of people that are talking about Europa. I wish this group was discussing it.         Astrobiologists Say Prometheus Jupiter Mission Should Have Landing Craft By Leonard David Senior Space Writer posted: 12:30 pm ET 11 February 2003   TEMPE, ARIZONA -- Scientists here at the NASA Astrobiology Institute General Meeting 2003 this week have welcomed the news that NASA’s Project Prometheus – work on nuclear electric propulsion – has picked as a flagship mission the exploration of the icy moons of Jupiter. To be flown within a decade, a nuclear-powered probe would search for evidence of global subsurface oceans on Jupiter's three icy Galilean moons, Europa, Ganymede, and Callisto. These oceans may harbor organic material, with the spacecraft moving from moon to moon, training an array of equipment on each world. Scientists have long thought Europa is a prime candidate for life. It’s one of the few places in the solar system where liquid water may be found. That being the case, a new phase of exploring the moon should include surface landers, contend astrobiologists meeting here. Site for life A special focus group on future Europa exploration is reviewing plans to understand better the moon and its promise of being a site for life. Any future exploration of Europa – about the size of Earth’s Moon -- should spotlight the identification of sites where signs of past or present life can be found and studied. That’s the view of Ron Greeley, a geology professor at Arizona State University (ASU). Greeley underscored the growing body of evidence that beneath Europa’s icy crust there is an environment favorable for present life – or where signs of past life may be preserved. Wanted: landers NASA’s decision to move out on a nuclear-powered mission to Jupiter has created some grumbling, however. "Most people, myself included, view this as a good thing," Greeley told SPACE.com. "The grumbling stems mostly from the skepticism that the first mission would take place on the time-table given because the needed development is substantial," he said. But once the capability is developed, "then there is high potential for science, not only with the ability to shift from one object to another, but also with the potential to carry landed packages," Greeley said. There is a consensus among Europa experts that getting something onto the surface of the moon early is key -- preferably as part of the orbiter mission itself -- rather than doing missions serially, Greeley said. Task at hand Europa has been the subject of repeated examination by the robotic Galileo spacecraft. That data has been critical in showing that Europa is home for a salty liquid ocean. But Greeley and other researchers here believe future studies of the moon will need to focus on surface missions. The task at hand is agreeing on areas across Europa where geologic processes have caused the icy crust to melt, and where organisms would be protected from radiation and provided with an adequate food supply. "Now that the Galileo mission is nearly completed, it is time for researchers to sift through the images to shape the current state-of-knowledge about the satellite [of Jupiter] and pose scientific questions to be addressed by future missions," said Patricio Figueredo, an ASU researcher studying the chances for life-on-Europa.