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Saturn and three moons  (Source: NASA)
Saturn's rings are older and are recycled

The shimmering rings encircling Saturn could be older than originally thought, scientists confirmed during the American Geophysical Union conference in San Francisco, California.  It was believed Saturn's rings were only 100 million years old -- created at the same time dinosaurs ruled the Earth. 

The Cassini spacecraft's data has made scientists revisit the issue and say the rings could have been created up to 4.5 billion years ago -- around the same time the rest of the solar system formed.

The rings around Saturn have intrigued scientists as far back as Galileo's time in the early 1600s.  Saturn has seven large rings and thousands of tiny ringlets composed of ice, dust and rock fragments.

"The evidence is consistent with the picture that Saturn has had rings all through its history," said Larry Esposito, principal investigator for Cassini's Ultraviolet Imaging Spectrograph at CU-Boulder.  "We see extensive, rapid recycling of ring material, in which moons are continually shattered into ring particles, which then gather together and re-form moons."

Data gathered by the NASA Voyager mission and Hubble Space Telescope made scientists believe the rings were young, and created when a comet slammed into a moon and destroyed it.  It was also assumed meteoric dust pollution would make older rings much darker than newer rings.  The lighter color is due to a unique recycling event with the rings, and it was also unveiled some rings around Saturn are older than others.



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By KingstonU on 12/13/2007 4:26:08 PM , Rating: 2
"...the rings could have been created up to 4.5 billion years ago - around the same time the rest of the universe formed."

The oldest rocks on Earth are estimated to be ~4.3 billion years old (found in Nunavut) and from that the Earth is estimated to be ~4.6 billion years old. So this is at least how old our solar system is. But are were all solar systems necessarily created at the same time? i.e. our solar system was created when the universe was created?




By Ringold on 12/13/2007 8:19:09 PM , Rating: 3
Many generations of supergiant stars had to live and die before a star system could form that had anything other than hydrogen, helium, and lithium. Everything heavier than those elements had to be formed by supernova. They're formed in those events, which then scatter them about, where they later join the party as new clouds condense to form new stars. Astronomers can date the age of stars by observing how much material is in them beyond the above three.

Which brings a question.. why would rocks be dated at roughly the same time as the solar system, when they are likely much older? Hopefully any forthcoming answer is simple enough that I don't regret asking. :P


By Sanity on 12/13/2007 8:31:49 PM , Rating: 3
Sure, the rocks in our solar system are made from material that's older than the solar system, just as you say. But where do you draw the line? Most of this was just dust from a supernova before it coalesced to form rocks and planets. Heck, maybe just gasses and atoms. Looking at it the way you are, aren't we all as old as the universe itself?


By Ringold on 12/13/2007 9:07:46 PM , Rating: 2
I phrased my question perhaps poorly, but I yanked the answer from wiki.

I didn't know how we could look at a rock here and say "Behold! The Earth is X years old!", as I thought dating methods could look at the process from the time the material was created; ie, before the solar system.

But wiki explained it:

quote:
If the rock becomes molten, as happens in the Earth's mantle, such non radioactive end products typically escape or are redistributed.


http://en.wikipedia.org/wiki/Age_of_the_Earth#Radi...

I haven't had a real physics class in a long, long time, so didn't know that.


By Goty on 12/13/2007 11:02:12 PM , Rating: 3
Correction, all elements higher than [b]Iron[/b] have to be formed in a Supernova. Iron is the limit at which nuclear fusion ceases to be exothermic.

Heavier elements than Iron are formed through fast neutron capture during a Supernova.


By kweshon on 12/14/2007 7:15:11 AM , Rating: 2
As I understood it, elements decay in different ways when floating around as a gas, as opposed to being bombarded by decaying elements nearby. So the relative occurence of isotoes in the universe at large is different from the ones on "earth".


Age of Universe = 13.7 billion years
By HilbertSpace on 12/13/2007 4:12:46 PM , Rating: 2
The title of the article is a bit misleading...




RE: Age of Universe = 13.7 billion years
By Rockjock51 on 12/13/2007 4:20:56 PM , Rating: 2
Article seems to have confused the age of the Universe with the age of the Solar System.


By marsbound2024 on 12/13/2007 4:38:14 PM , Rating: 3
Ugh, DailyTech I am very disappointed. At least READ the news release before reposting it in such a misleading manner:

http://www.jpl.nasa.gov/news/news.cfm?release=2007...

"SAN FRANCISCO, Calif. – New observations by NASA's Cassini spacecraft indicate the rings of Saturn, once thought to have formed during the age of the dinosaurs, instead may have been created roughly 4.5 billion years ago, when the solar system was still under construction."

Most people by now should know that the Universe is almost 14 billion years old.


Universe is much older than the rings...
By jskirwin on 12/13/2007 4:14:03 PM , Rating: 2
Here's the quote from the article:
quote:
However, new data from the orbiting international Cassini spacecraft suggest the rings existed as far back as 4.5 billion years ago, roughly the same time the sun and planets formed.


The universe is much older than the solar system by about 9-11 billion years.




By retrospooty on 12/13/2007 5:14:20 PM , Rating: 2
Yes, I think it was a typo, or mis-quote. Our solar system is 4.5 billion years old.


Rethinking formation of solar system
By phattyboombatty on 12/13/2007 6:59:20 PM , Rating: 2
The general consensus for the origins of the planets in our solar system is that there was a large disk of space dust surrounding the sun that over time clumped together into the planets.

Thus, scientists have been very interested in the Saturn rings for a long time because they thought it was a similar model to the early solar system and could use the rings to learn more about how the planets may have formed.

But now, if the rings have pretty much existed without change for 4.5 billion years, doesn't it cast doubt on the theory that the planets formed from a disk of small particles? It seems that the disk would suffer from the same issues that keeps the rings from grouping into large bodies--as soon as a small clump forms it gets destroyed by collisions with other particles.

Doesn't this also cast doubt on the current theory of the origin of our own moon?




By Sanity on 12/13/2007 8:24:36 PM , Rating: 2
Size matters. I'd be willing to bet that the moons they are talking about breaking up and re-forming, are tiny in comparison to our moon. Saturn has larger moons that have probably been around just as long, but have never broken up due to their size and composition. Who knows, the larger moons may have had molten cores at one time. From what they can tell, the rings don't have enough material for gravity to condense it to the point of melting under pressure. It'd be like a big dust ball waiting for someone to sneeze.

The Sun's planetary disk is a different animal all together. Enough material to form all the planets. Enough gravity to keep them all together. Ever seen a size comparison of all of the planets next to each other? Gravity is a beast. Jupiter scares me, and it's tiny compared to the Sun.


Count the rings
By Mitch101 on 12/13/2007 5:46:10 PM , Rating: 2
Scientist just making things more complicated. I'm sure its like a tree just count the rings to tell how old it is?

;)




Did i miss the memo?
By RandallMoore on 12/14/2007 5:25:02 PM , Rating: 2
Is DT featuring the theory of evolution this week or something? I dont know how this is called science. I really dont, cause its nothing that we can observe.




"Young lady, in this house we obey the laws of thermodynamics!" -- Homer Simpson











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