Couldn't they use a stripped down version of Europa Clipper, as Saturn has a less fearsome radiation environment, as an Enceladus Clipper?I can't help feeling maybe we should be going to Enceladus first not Europa?Some reporting of what I assume is the Q & A session.https://mobile.twitter.com/EBotkinKowacki/status/852585362362949633
Quote from: Star One on 04/13/2017 06:37 pmCouldn't they use a stripped down version of Europa Clipper, as Saturn has a less fearsome radiation environment, as an Enceladus Clipper?I can't help feeling maybe we should be going to Enceladus first not Europa?Some reporting of what I assume is the Q & A session.https://mobile.twitter.com/EBotkinKowacki/status/852585362362949633I admit that personally I'd rather see an Enceladus mission. However, Cassini was able to study Enceladus better than Galileo did with Europa. That puts Europa at a disadvantage as it makes it seem less interesting. Clipper could discover a bunch of new things about Europa that make it potentially the better place for further study.
Quote from: notsorandom on 04/13/2017 07:17 pmQuote from: Star One on 04/13/2017 06:37 pmCouldn't they use a stripped down version of Europa Clipper, as Saturn has a less fearsome radiation environment, as an Enceladus Clipper?I can't help feeling maybe we should be going to Enceladus first not Europa?Some reporting of what I assume is the Q & A session.https://mobile.twitter.com/EBotkinKowacki/status/852585362362949633I admit that personally I'd rather see an Enceladus mission. However, Cassini was able to study Enceladus better than Galileo did with Europa. That puts Europa at a disadvantage as it makes it seem less interesting. Clipper could discover a bunch of new things about Europa that make it potentially the better place for further study.Would an Enceladus mission be automatically cheaper due to the less strenuous radiation environment?
Quote from: TakeOff on 03/15/2017 11:53 amI wonder how the heating occurs on a pole instead of at the equator, where tidal effects are the greatest on earth?I believe it might be a case of the region with the thinnest ice reorienting itself to one of the poles due to a tidal gradient on a non-spherical body. IIRC, the active south polar region is actually topographically slightly depressed compared to the rest of the ice shell on account of liquid water underneath having higher density than bulk ice. It doesn't mean there's necessarily a mechanism that somehow concentrates the heating to the pole, just that the largest liquid pocket ended up there on account of either ice shell (if the ocean is really global, but deepest at the pole) or entire moon rotational drift.
I wonder how the heating occurs on a pole instead of at the equator, where tidal effects are the greatest on earth?
Quote from: Star One on 04/13/2017 07:21 pmQuote from: notsorandom on 04/13/2017 07:17 pmQuote from: Star One on 04/13/2017 06:37 pmCouldn't they use a stripped down version of Europa Clipper, as Saturn has a less fearsome radiation environment, as an Enceladus Clipper?I can't help feeling maybe we should be going to Enceladus first not Europa?Some reporting of what I assume is the Q & A session.https://mobile.twitter.com/EBotkinKowacki/status/852585362362949633I admit that personally I'd rather see an Enceladus mission. However, Cassini was able to study Enceladus better than Galileo did with Europa. That puts Europa at a disadvantage as it makes it seem less interesting. Clipper could discover a bunch of new things about Europa that make it potentially the better place for further study.Would an Enceladus mission be automatically cheaper due to the less strenuous radiation environment?It could last longer, but would not be cheaper due to the need for an RTG for power. Also depends if the probe is flying through the plumes to collect samples for return to Earth. Sample return will drive up mission costs.
Quote from: Star One on 04/13/2017 06:37 pmCouldn't they use a stripped down version of Europa Clipper, as Saturn has a less fearsome radiation environment, as an Enceladus Clipper?I can't help feeling maybe we should be going to Enceladus first not Europa?Some reporting of what I assume is the Q & A session.https://mobile.twitter.com/EBotkinKowacki/status/852585362362949633There is at least one New Frontiers proposal for a mission to return to Enceladus. It is very narrowly focused on chemical analysis of the plumes; e.g., no study of the ice shell thickness or imaging to inform potential future landers.Seehttp://www.lpi.usra.edu/opag/meetings/feb2017/presentations/Cable.pdf
So Enceladus has hydrogen and methane? Certainly puts it on level with Europa for interest level at the least.
Quote from: redliox on 04/13/2017 09:15 pmSo Enceladus has hydrogen and methane? Certainly puts it on level with Europa for interest level at the least.And regular plumes. Makes it far easier to sample than Europa. To me Enceladus is far more deserving of a mission for that reason.
Quote from: Graham on 04/13/2017 10:58 pmQuote from: redliox on 04/13/2017 09:15 pmSo Enceladus has hydrogen and methane? Certainly puts it on level with Europa for interest level at the least.And regular plumes. Makes it far easier to sample than Europa. To me Enceladus is far more deserving of a mission for that reason.But I suppose the counter argument to that is because Europa is believed to be 4 billion years old compared to some estimates that Enceladus is only 100 million years old that life, if that's what you're looking for, is far more likely to have had the time to get started on Europa.
Lead story on BBC Radio 5 this morning on their discussion program. They are also talking about space science in general and that can only be a good thing.
Quote from: Star One on 04/14/2017 08:43 amLead story on BBC Radio 5 this morning on their discussion program. They are also talking about space science in general and that can only be a good thing.Not really if it's the BBC. That network's religious insistence of ecumenical reporting requires them to give equal airtime to dumb statements like: "some people say we should solve all of Earth's pressing problems before devoting resources to space exploration" in every single article they write....
Congress, in its fiscal year 2016 appropriations bill, directed NASA to develop an “Ocean Worlds Exploration Program” to search for life on such worlds using a mix of small and large missions. That language was included by Rep. John Culberson (R-Texas), chairman of the appropriations subcommittee that funds NASA and a strong advocate for missions to Europa in particular.A formal program is still being established within the agency, officials said at the briefing. Mary Voytek, astrobiology senior scientist at NASA Headquarters, said a “roadmap” document outlining studies of ocean worlds is in the final stages of development by an advisory group. “They’re about to deliver that to us any day now,” she said. That document, she said, will set science priorities and technology requirements for any future missions.Some scientists have questioned whether Enceladus, with its constant plumes containing chemical energy that could support life, may be a better initial target than Europa. Voytek noted that the presence of hydrogen in the plume indicates that it is not being consumed by any life that might exist in the oceans in Enceladus. “It means that there might not be life there at all, and if there is life, it’s not very active,” she said.She speculated that could be linked to the age of Enceladus, which may be much younger Saturn itself. Europa, by contrast, was formed at the same time as Jupiter, more than four billion years ago. “That’s a lot more time for life to have emerged and start taking advantage of these energy sources,” she said. “So my money, for the moment, is still on Europa.”