Nasa Picks "juno" As Next New Frontiers Mission |
Nasa Picks "juno" As Next New Frontiers Mission |
Guest_BruceMoomaw_* |
Jun 1 2005, 10:10 PM
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Guests |
http://www.nasa.gov/home/hqnews/2005/jun/H...rontiers_2.html
Yeah, I know it ain't Saturn, but we don't seem to have any proper slot for Jovian news -- including yesterday's totally unexpected announcement that Amalthea's density is so low as to suggest that it's a highly porous ice object; maybe a captured Kuiper Belt Object reduced to rubble by infalling meteoroids. As Jason Perry says, this might explain those previously mysterious light-colored patches on Amalthea -- they may be its underlying ice, exposed by impacts that punched through the layer of sulfur spray-painted onto it by Io. Scott Bolton has been pretty talkative to me already about the design of Juno. It certainly won't be as good in the PR department as Galileo or Cassini, but it DOES carry a camera -- as much for PR as for Jovian cloud science, according to Bolton. And since the latitude of periapsis of its highly elliptical orbit will change radically during the primary mission, I wonder if they might be able to set up at least one close photographic flyby of Io and/or Amalthea? (I believe, by the way, that this selection is a bit ahead of schedule -- and it certainly indicates that NASA's science program under Griffin won't be a complete slave to Bush's Moon-Mars initiative.) |
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Guest_Myran_* |
Jun 8 2005, 12:12 PM
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dvandorn wrote:
"I think the most boring thing we could possibly find on Europa would be -- fish. Regular old fish, with scales and gills and DNA and everything. But it would sure hint at some common ancestor to life on both worlds, wouldn't it?" Its true that active swimmers would have to be streamlined to travel efficiently in water, but no or extremely little oxygen would mean no gills and active swimming less likely. (No photosynthesis possible under a mile of ice). If there any life on Europa its more likely to be colonies of organisms gathered around warm springs getting their nourishment from chemical processes, what shape they might have im not qualified to even speculate about. The big question is if liquid water and volcanic heat is enough to get life started. -"- As for sampling and investigating deeper down: The idea of a robot that melts itself down to reach any possible ocean beneath the ice is a clever idea, but its not even on serious consideration so I wont see it in my lifetime. |
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Jun 8 2005, 04:47 PM
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
QUOTE (Myran @ Jun 8 2005, 05:12 AM) As for sampling and investigating deeper down: The idea of a robot that melts itself down to reach any possible ocean beneath the ice is a clever idea, but its not even on serious consideration so I wont see it in my lifetime. (GOING STILL FURTHER OFF TOPIC, HERE) Back in the salad days before we knew so much, it seemed possible to melt through the ice. But two compounded difficulties pretty much kill that idea. One, the ice is much deeper than we might have hoped. 20 km seems to be the direction that the evidence is pointing. Then, the factor that makes that especially lethal is that if the ice has any impurity at all, melting through it would cause the impurity to accumulate at the bottom of the hole, eventually creating a mass of salt or somesuch, which heating to 10C would not make go away. Enceladus could stand in as a new arena for the exact same hopes. Cassini's early imaging seemed to deflate those hopes, for, although Enceladus showed young surface, it also showed considerable relief, which means the ice must be relatively thick (even when you allow for the very weak gravity). But, the last flyby of the south pole showed "tiger stripes" analogous to Europa's triple bands, and nonimaging instruments indicate that H2O seems to appear in Enceladus's vicinity at a considerable rate -- these results may combine to indicate that live geysers exist at high latitudes, which would provide a possible point of axis for a Enceladus Underwater Explorer (???). Not to help Myran too much, though -- I don't see that happening in our lifetimes, either! |
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