GAry 7

So you’d ruin the pristine space environment with nukes and radiation? How are the poor alien mothers going feel when their alien babies are born with 10 tentacles instead of eight?

According to Wikipedia — Enceladus (moon), the Ion and Neutral Mass Spectrometer (INMS) and the Ultraviolet Imaging Spectrograph (UVIS) both confirmed that the plumes emanating from Enceladus’s south pole region is, indeed, water vapor, but no ammonia was detected in the vented material by INMS or UVIS; however, simple and complex hydrocarbons such as propane, ethane, and acetylene were detected.

And yes, spectra show that these guys are mostly water ice. I don’t think that there are any confirmed detections of ammonia on Enceladus yet, for example.

So you don’t like your taxes going to stuff you don’t like? Waaah. Stuff happens. You do realise though that Australia and NASA have had for decades a long standing partnership in operations and facilities in Australia? Facilities, operations and the support of manned space flights and the purely robotic space missions? What? Can it be that Australian tax payers have a stake too?

Look, I’ll put it in a way you might understand. Some people don’t want to pay for any space exploration at all while there is poverty on earth. What would you say to them? I would suggest your arguments would be very similar to ours, those who believe in manned space exploration.

He who pays the piper, Mr. SLC from the USA, may call the tune but it doesn’t mean we can’t hum along or dance to that tune.

By the way I have no comment on US taxpayers.
Well, except for this, are the 40% of Americans who do not pay tax entitled to an opinion? Or are you of the opinion that should be no representation without taxation?

GAry 7

I suggest that Mr. shane from Australia who apparently, like Dr. Plait is all in favor of manned space flight, not comment on US taxpayers who have to shell out for this activity. He who pays the piper calls the tune and Mr. shane in Australia isn’t paying the piper.

http://www.urbandictionary.com/define.php?term=broken%20record

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I meant :

Excellent news – great week for space exploration with this & the MESSENGER fly-past of Mercury succeeding.

@ SLC & others dissing manned spaceflight : I don’t think the two (humans or robots) are necessarily mutually exclusive but rather that they could be considered complementary.

As an SF fan, I like to think of this as the preliminary recconnosance (spelling?) by our robot proxies before we humans eventually get out there in the flesh.

The other way of thinking may be this : How much cooler would this be if there were real living people aboard a ship investigating Encleadus – how much more could they spot and act on and do?

One day hopefully, when the technology has grown better and the travel times dropped, I’d love to see people land on Enceladus.

(Or would the radiation level be too high? I know the Jovian Gaililean moons are all deeply radioactive because of Jupiter’s equivalent of the Van Allen belts – is this as bad at Saturn?)

Anyway, for now I’m just marvelling over these images and those of Mercury too and proud to see both encounters at opposite ends of our solar system* have gone so well.

THX Bad Astronomer.

PS Thinking of Mercury are all the images / info. from that fly-by in now or is there more still to come? Did they find that volcano suggested by the Arecibo data? (See ‘MESSENGER fly-by tonight’ thread here.)
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* Yeah I know strictly speaking Mercury is at one end but Pluto – or Eris or Sedna is at the other NOT Saturn. Spekaing metaphorically or poetically here.

SLC & others dissing manned spaceflight I don’t think the two (humans or robots) are necessarily mutually exclusive but rather could be considered complementary. As an Sf fan Ilike tothink of this as the preliminary reconnosience by Robots before we humans eventuallyget out there.

The otherway of thinking may be -how much coooler if there werereal people aboard ashipinvestigating Encleadus -how much mor ecould theyspot and acton and do?

One day hopefully, whenthetechnology has grown betertr and the travel times dropped I’d love to see people on Enceladus.

(Or would the radiation level be too high? I know the Jovian Gaililean moons are all deeply radioactive because of Jupiter’s equivalent of the Van Allen belts – is this as bad at Saturn?)

Anyway, fornowe I’m justmarvelling over these images and those of Mercury and proiud to see both encounters atopposite ends of our solarsystem have gone so well.

THX Bad Astronomer.

Moons in the extensive satellite systems of gas giants often become trapped in orbital resonances that lead to forced libration or orbital eccentricity; proximity to the planet can then lead to tidal heating of the satellite’s interior, offering a possible explanation for the activity. [...]

Enceladus orbits Saturn at a distance of 238 000 km from the planet’s center and 180 000 km from its cloud-tops, between the orbits of Mimas and Tethys, requiring 32.9 hours to revolve once (fast enough for its motion to be observed over a single night of observation). Enceladus is currently in a 2:1 mean motion orbital resonance with Dione, completing two orbits of Saturn for every one orbit completed by Dione. This resonance helps maintain Enceladus’s orbital eccentricity (0.0047) and provides a heating source for Enceladus’s geologic activity. [...]

[Assuming that Enceladus is a differentiated body, i.e., a silicate core with a water-ice mantle, subsequent heating from the decay of certain radioactive elements] and tidal heating would raise the temperature of the core to 1000 K, enough to melt the inner mantle. However, for Enceladus to still be active, part of the core must have melted too, forming magma chambers that would flex under the strain of Saturn’s tides. Tidal heating, such as from the resonance with Dione or from libration, would then have sustained these hot spots in the core until the present, and would power the current geological activity.

Click on my name for the direct link to the article and a more detailed explanation with cool pix.

I wonder what it would do if you could shake it?

How strong are the tidal forces from Saturn? Are they enough to deform the moon and crack its surface? To heat it up and melt the ice so it’s floating on a layer of liquid water?

Thanks again, Phil.

http://cdn.buzznet.com/assets/users9/sandraluihn/default/zamboni–large-msg-1127216292-2.jpg