If i could live for 100 years it would be just to see what new exciting changes come from the cosmos. What a great time to live in if you are interested in Science and space exploration.

here, you took the words right out of my mouth!!!!!

Totally cool!

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Amazing what NASA and the Planetary Scientists can do on a fraction of the cost of the manned programs. Hence the old debate "Heroes or Robots?"

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We will need BOTH manned and robotic deep space capability if we are to survive in our "free fire zone" of the cosmos. Bruce Willis notwithstanding, we don't have ANY serious counter for city- or planet-killer rocks headed our way...

What heat? Without a substantial atmosphere the meteors and asteroids would not be superheated before striking the surface of Rhea as there would be no friction. It would be a "cold" impact. The ice would be shattered, but not melted.

Craig, pressure causes heating. You know, like the pressure of impact. Pedagoguish asked a logical, thoughtful question. Instead of dismissing it, try to answer it. Personally, I would think it might be because the water didn't remain liquid long enough to flow. Do you have anything to add?

The impact alone would cause heat.

The impact creates energy. The moon does have an atmosphere therefore there is some heat but with the cold enviroment if there is any melting it would freeze very quickly. The impacts makes craters, holes in the ground, and what ever water,if any there were would not escape the crater.

We have to dispense with the notion of Ice as we know it. Ice in the outer solar system away from Earth's " Goldilocks Zone " where water is mostly liquid or a fluid solid, is best considered to be like Stone. Or Concrete. The ice of Rhea is more geologic than hydrodynamic , at least on the exterior of the world.

Under the crust, maybe a different scenario will be detected. Moon like Jupiter's Europa could very well indeed have liquid oceans under a harder surface, and Neptune's moon Triton has been shown to have fascinating water-based geysers erupting hundreds of kilometers into space. Water does a lot of tricks, takes a lot of forms.

Kurt Vonnegut envisioned Ice Nine , an ice so cold it would creep outwards freezing all in its path with Absolute Zero thermal efficiency. That's a stretch , but I'll go so far as Ice Six or maybe Seven...

I think her point is that there will not be another mission to Saturn during our lifetime.

Thanks, Congress.... We really appreciate that all you Greedy Obstructionist Party hacks so desperately want to cut everything but taxes for the Fat Cats to whom you're beholden.

If you all could get off your partisan high-horse, and realize that there is so much bigger than your narrow-minded ideology, then us little people, (the 47% your failed presidential candidate mocked) could grow and benefit more from belonging to this great society. Unfortunately, you measure us all by how much money we can contribute.

How narrow minded.

The Evil Tessmacher

Thanks, Congress.... We really appreciate that all you Greedy Obstructionist Party hacks so desperately want to cut everything but taxes for the Fat Cats to whom you're beholden.

Pull your head out, The only one on a "partisan high-horse" is YOU. Dems had total control of Congress for 4 years and that was when the NASA budget started to take even more hits. Now under a democratic administration the percentage of the budget that goes to NASA is at an all time low. Only a blind puppet would blame it on one party especially when that party isn't even in power.

Gentilemen, If I can use the term, this is how Government works. It get industries started and than lets them start to earn their own way, it is the way of the Capitalist. The Government started Satillites and now Businesses have their own and the Government is not in the Business of putting up everybody toy in Space. If the Government hadn't done what it did to start thing going there probably wouldn't be an internet today, You wouldn't have cell phones, and the computer would just be an information storage device used by offices.

Evil, The Dems and Obama are bragging about how they cut Nasa. For that matter it's about the only program they could come up with when asked what have they cut in the Fed budget.

The Evil Tessmacher, I guess you failed government in High School. The Executive Branch by the Constitution requires the President submit a proposed budget to congress. Obama is not the first president to dodge his responsibilities. "The Budget and Accounting Act of 1921 (Pub.L. 67–13, 42 Stat. 20, enacted June 10, 1921) was landmark legislation that established the framework for the modern federal budget. The act was approved by President Warren G. Harding to provide a national budget system and an independent audit of government accounts. The official title of this act is "The General Accounting Act of 1921," but is frequently referred to as "the budget act," or "the Budget and Accounting Act."[1] This act meant that for the first time, the president would be required to submit an annual budget for the entire federal government to Congress."

So Obama is solely responsible for the lack of a budget and is in violation of Federal Law and Congress should impeach him. We need a leader and not a half-bake charlatan…

6dogs

Gentilemen, If I can use the term, this is how Government works. It get industries started and than lets them start to earn their own way, it is the way of the Capitalist.

Government isn't supposed to work this way and it has NOTHING to do with capitalism. Nothing the government does comes without strings or cronyism. Capitalism leaves failed ideas in the trash whereas government just continues to prop them up. Capitalism spends the money where there is money to be made, Government spends its money where the biggest campaign contributions can be found.

If the Government hadn't done what it did to start thing going there probably wouldn't be an internet today, You wouldn't have cell phones, and the computer would just be an information storage device used by offices.

This is the biggest BS myth out there. If we'd have none of those things without government how on Earth did we get along before the government got involved in things they were never intended to?? How did any of the prior innovations and advancements take place? The Internet generates billions in revenue, the notion that it never would have happened without the government being involved is far beyond laughable.

GTFO with all this political crap. This article is about science biatches, not politics.

Sounds like we were born lucky to me.

Here's a link to a paper regarding the first flyby. Rhea has both H2O ice and CH4 ice.

http://arxiv.org/ftp/astro-ph/papers/0512/0512115.pdf

If the hydrogen was separated from oxygen due to charged particles from Saturn, could they also have been separated from carbon (in methane), creating free radicals of each?

@Jay, In my mind yes. C-H bond in methane takes ~105 kcal/mol to break while a O-H bond in water takes ~110 kcal/mol to break. There are some other factors like are the bonds being broken homo or heterolytically. And forming CO2 is thermodynamically favorable. What is not discussed in this article is the maybe there isn't enough methane on the surface to contiunually replenish the CO2 that drifts off into space fast enough (I'm assuming the moon doesn't have enough gravity to hold an atmosphere indefinetly, but I may be wrong).

Gentlemen,

Space.com published this after the last fly-by (2010):

Rhea's mystery carbon dioxide

The researchers say they are pretty sure they know where Rhea's atmospheric oxygen is coming from - charged particles from Saturn's magnetosphere blasting apart molecules of water ice. The source of the carbon dioxide, however, is more mysterious.

It's possible that Rhea, like many other solar system bodies, has carbon-rich organic molecules on or near its surface, researchers said. These organics could be split apart by Saturn's charged particles, just like Rhea's ice. Liberated carbon and oxygen could combine, forming carbon dioxide.

Micrometeorite bombardment could also be delivering the carbon for such reactions, according to the researchers.

It's also possible that carbon dioxide is escaping from Rhea's interior fully formed. The gas could be primordial - left over from the moon's formation about 4.5 billion years ago - or it could be the product of long-ago reactions inside Rhea, which now appears to be geologically dead.

"We have no idea at this point which one of these mechanisms is producing it," Teolis said. "That's definitely something we want to look at in the future."

Honestly, it never occured to me that Saturn could be emitting charged particles with that kind of energy. It makes sense - I just never thought about it before.

In any case, thanks for the paper, Jay, and the insights, Dr. Chuck. More at the link, if you're interested.

@ Dr. Chuck, even Mars isn't massive enough to retain free atmospheric hydrogen, so that would likely go first/fastest. Our Moon is over twice Rhea's diameter and is certainly much more massive (even if I haven't checked the exact stats), so Rhea can't retain atmospheric gases 'as well' as our Moon. So, if our Moon only has trace emissions (or, at best, a micro-atmosphere), Rhea must have its (temporary) atmosphere replenished.

GA Gentlemen!

I'm curious Art, why do you suppose only two people will go to Mars. Are you privy to inside information from NASA, or is two all that you think will be needed.

Not a direct flight at all. Check the flight path. It took the long way there that's for sure.

fyte 4 justice

I'm curious Art, why do you suppose only two people will go to Mars. Are you privy to inside information from NASA, or is two all that you think will be needed.

I assume he's referencing this- http://cosmiclog.nbcnews.com/_news/2013/02/27/17107722-millionaire-dennis-tito-plans-to-send-woman-and-man-to-mars-and-back?lite

Carbon Dioxide??? You don't suppose they hold political conventions there?

It's defenders

There should be no apostrophe in that word its, which makes your intellect suspect.

...and what does questioning someone's intellect over a misplaced apostrophe do to yours?

It makes me right and him wrong. You got a problem? Take it up with Webster's.

Like no one has ever made a mistake before.

Heck, they elected and re-elected Obama. The man with a bogus fake birth certificate and a stolen SNN, marxist mentor Frank Marshall Davis and a bunch of racist and commie buddies and a convicted terrorist, Bill Ayers that launched his political careeer.

Like that has a lot to do with global warming, let alone a moon of Saturn.

Mental health ISSUES!!

but no definitive proof, especially of humankind's contribution to it.

Rex,

I believe I've explained this to you before, so it's surprising to see it crop up here again.

The human fingerprint of global warming is very clear. Carbon has isotopes (some carbon nuclei have 12 neutrons, some have 13, and a few have 14). Plants prefer carbon with 12 neutrons.

So when we burn old plants (aka, fossil fuels), the amount of carbon with 12 neutrons in the atmosphere increases.

And that's exactly what we see. Not only is the total amount of atmospheric CO2 rapidly climbing (from 'normal' levels of 280ppm or less, to the highest levels seen in 15 million years), but the ratio of 13-neutron/12-neutron carbon in our atmosphere is also falling off a cliff.

This isn't rocket science. It's us.

I don't expect to convince you of anything - even with empirical data like this. But other may read your post, and have 'doubt'. And that's all science deniers have to do - introduce 'doubt'. It worked for tobacco, and now it's working for the fossil fuel industry.

Don't be fooled. It's us. Every accredited scientific organization in the world agrees with that statement.

Rex, you are absolutely correct to say the CO2 problem is a global problem. You are also correct in stating that "humankind's" contribution is somewhat of a question. What's not in question is that CO2 levels are increasing faster than any time that we know of. We know that increased CO2 will result in higher temperatures, world wide, and will affect all aspects of weather. We, also, know that increased CO2 is causing increasing acidification of the oceans, creating issues for many animals and plants in the oceans. The fact that a vast majority of our oxygen comes from the plants in the oceans is concerning.

The bottom line is that while we can't say how much humans are contributing to the increases in greenhouse gasses, there is no doubt we are contributing some. We also know that even if we could completely do away with the introduction, natural or man made, greenhouse gasses into the atmosphere, it would still take years to reduce levels to where they were just 100 years ago. If we wait until we are absolutely sure of how much we are contributing to climate change, we may be past a tipping point where our quality of life will be severely and negatively impacted.

Great minds discuss ideas; average minds discuss events; small minds discuss people. -Eleanor Roosevelt-

Thank you Doug.

@tiredofhypocrites-794827,

Great posts thumbs up for all :)

Regards,

Brandon

while we can't say how much humans are contributing to the increases in greenhouse gasses

We actually have a very good handle on that, tired - 35.6 billion metric tonnes last year, and about 500 billion metric tonnes since the beginning of the Industrial Revolution.

Why would you think we don't know that?

Doug, "There should be no apostrophe in that word its, which makes your intellect suspect."

"It's" is possesive in this case. Look it up before you start pointing out flaws in other's intellect.

As for the whole global warming thing: ClimateGate invalidated the science behind it. You can't change data to make your point; that isn't scientific method, it is propaganda. That said, a recent independent study has proven climate change to be a fact. But as was stated in the study; they only proved the fact that it was happening, not our contribution to it. Until they finish that study, any claims of our causing the effect is pure conjecture; regardless of your (possibly well founded) beliefs.

Physicist, "Plants prefer carbon with 12 neutrons." . AYEYIYIYI! Seriously? You claim to be a scientist and you believe that? You should have paid more attention in chemistry. Carbon isotopes are chemically identical. A plant doesn't care which it is as long as it is. Neutrons, by the very definition, are charge neutral and have no effect on reactivity of an element. As a physicist, you should be very aware of this as it is ELEMENTARY PHYSICS! Are you sure you aren't a liberal arts major?

P.S. The reason fossil fuels have less C13/C14 is because, when the plant died, the carbon exchange ceased and the isotopes started decaying back to C12/N14. Not because "Plants prefer carbon with 12 neutrons." Criminy, you make my head hurt everytime I consider that statement.

Physicist, I just now went to your link. "the ratio of 13-neutron/12-neutron carbon in our atmosphere is also falling off a cliff." You seriously don't understand the data that was presented, do you? The ratio of C13/C12 is approximately the same; considering that carbon isotopes are formed in the upper atmosphere that is no surprise. Now what the data does show is a fall off of OXYGEN. I imagine that if we keep deforesting South America, that trend will continue. I also imagine that you will continue to cite very official and scientific looking charts to back up your statements; counting on the layperson to not understand what they are reading.

Physicist, you are absolutely correct. I knew what I was thinking but that didn't translate to what I was typing. I meant to say that I don't know how much, percentage wise, our contribution to greenhouse gasses is contributing to climate change when considering the greenhouse gasses already present and those being contributed by natural events.

Tired,

The fact is, we do indeed know, rather precisely (i.e., in Watts per meter squared) human and natural contributions to the planet's warming:

http://en.wikipedia.org/wiki/File:Radiative-forcings.svg

Feel free to ask if you have any questions about that graph.

@Blue N Gold,

"Two? 2? Only two pictures?"

Here ya go "Sparky" directly from the NBC article that apparently you and the 1 (ahem) Genius that voted for you can't read.

"The flyby was designed primarily to measure Rhea's gravity field, mission scientists said. But Cassini also managed to take 12 pictures of the frigid moon's battered, pockmarked surface, including one that showcases a mysterious long, curving fracture called a graben."

Or for even more pictures (cuz words R 2 complicated) try: h-ttp://www.nasa.gov/mission_pages/cassini/multimedia/latest-images-collection_archive_43.html

With 43 pages and about 20 pictures per page surely you can find something to look at that doesn't require reading.

"What is NASA hiding that the hundreds of thousands of pictures taxpayers have paid for get released one or two at a time?"

Ummmmm................You do realize that this is an NBC News article and NBC decides which and how many pretty pictures to use. Or do you ? lolz Do you know that NASA has sections dedicated to the: Public, Educators, Students and the................ (wait for it)..........MEDIA (like NBC News)? Where ANYONE ( yes Sparky even you too ;) can go for information, SELF discovery and exploration. I hope that you understand that it is not NASA's job to spoonfeed you and then have to change your Poopy Diapers when a little initiative is all that is required to find things. Then again just keep thinking that NASA is holding out and dream up some retarded conspiracy theories. That way I can keep making fun of the Intellectually Challenged - LOLZZZ

The older this agency gets the less likable more loveable it is. ©2013 - There all fixed and muuuuch better now:)

Regards,

Brandon

I am betting your a moon landing is a hoax goon