Again the Saturn rings

pixel01

Hi all,

I have read this article about Saturn rings:
http://www.space.com/news/ap-071213-saturn-ringage.html

The author argues as:
Quotes:
"The notion that Saturn's rings may be a permanent feature was based on observations by the ultraviolet spectrograph instrument on Cassini, which viewed the light reflected from the rings and watched stars passing behind them".

In fact I could not understand why for that reasons, they can say the rings are as old.

Thanks for any help.

mgb_phys

It's more that the observations remove the need to assume that they are young!

They were assumed to be young because there are bright clean ice (from IR measurements made form the ground and Hubble) it was thought that if they were old, lots of dust would have built up on them from meteors and so on.
The Cassimi obserations showed that there was a lot more material in the disks than thought so the small quantity of meteor dust present doesn't imply a young age.

pixel01

Thank you, now I understand.
But it seems the article did not mention what you said. What I read is "..viewed the light reflected from the rings and watched stars passing behind them".

mgb_phys

Because they took the real press release and re-wrote it, badly.
http://www.jpl.nasa.gov/news/news.cfm?release=2007-149