Thickness of Saturn's rings

Has the Cassini probe led to an accurate figure for thickness of Saturn's
rings yet? The estimates vary widely even in relatively modern textbooks.
I've heard that they may be only 30 feet in maximum thickness. Hard to
believe that something so thin can be seen right across the solar system.

"Nightshift" wrote in message
...
Has the Cassini probe led to an accurate figure for thickness of Saturn's
rings yet? The estimates vary widely even in relatively modern textbooks.
I've heard that they may be only 30 feet in maximum thickness. Hard to
believe that something so thin can be seen right across the solar system.


http://saturn.jpl.nasa.gov/faq/saturn.cfm#q4
How thick are the main rings?


They're extremely thin compared to their breadth, no more than 100 meters
(about 300 feet) thick. To get an idea of their proportions, imagine a ring
as thin as a sheet of paper and about 3 km (2 miles) in diameter.

"Weatherlawyer" wrote in message
oups.com...

Chris Taylor wrote:
"Nightshift" wrote in message
...

Has the Cassini probe led to an accurate figure for thickness of
Saturn's
rings yet? The estimates vary widely even in relatively modern
textbooks.
I've heard that they may be only 30 feet in maximum thickness. Hard to
believe that something so thin can be seen right across the solar
system.

http://saturn.jpl.nasa.gov/faq/saturn.cfm#q4
How thick are the main rings?

They're extremely thin compared to their breadth, no more than 100 meters
(about 300 feet) thick. To get an idea of their proportions, imagine a
ring
as thin as a sheet of paper and about 3 km (2 miles) in diameter.

Seeing that there is so much solar exploration going on, might now be a
time to ask if anyone has actually pinpointed a star yet? I imagine a
distance of several astronomical units should be enough to get a
paralax measurement by now. How far is Saturn; 10?

Google
1838 Bessell 16 Cygni

"OG" wrote in message
...

"Weatherlawyer" wrote in message
oups.com...

Chris Taylor wrote:
"Nightshift" wrote in message
...

Has the Cassini probe led to an accurate figure for thickness of
Saturn's
rings yet? The estimates vary widely even in relatively modern
textbooks.
I've heard that they may be only 30 feet in maximum thickness. Hard to
believe that something so thin can be seen right across the solar
system.

http://saturn.jpl.nasa.gov/faq/saturn.cfm#q4
How thick are the main rings?

They're extremely thin compared to their breadth, no more than 100
meters
(about 300 feet) thick. To get an idea of their proportions, imagine a
ring
as thin as a sheet of paper and about 3 km (2 miles) in diameter.

Seeing that there is so much solar exploration going on, might now be a
time to ask if anyone has actually pinpointed a star yet? I imagine a
distance of several astronomical units should be enough to get a
paralax measurement by now. How far is Saturn; 10?

Google
1838 Bessell 16 Cygni

Ooops, that should be 61

JRS: In article , dated Fri, 21 Apr 2006
21:30:38 remote, seen in news:uk.sci.astronomy, OG
posted :
Seeing that there is so much solar exploration going on, might now be a
time to ask if anyone has actually pinpointed a star yet? I imagine a
distance of several astronomical units should be enough to get a
paralax measurement by now. How far is Saturn; 10?

Google
1838 Bessell 16 Cygni

Ooops, that should be 61

It should also be Bessel. You could add Struve, or try Henderson 1832.

--
© John Stockton, Surrey, UK. Turnpike v4.00 MIME. ©
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

In message .com,
Weatherlawyer writes

Chris Taylor wrote:
"Nightshift" wrote in message
...

Has the Cassini probe led to an accurate figure for thickness of Saturn's
rings yet? The estimates vary widely even in relatively modern textbooks.
I've heard that they may be only 30 feet in maximum thickness. Hard to
believe that something so thin can be seen right across the solar system.

http://saturn.jpl.nasa.gov/faq/saturn.cfm#q4
How thick are the main rings?

They're extremely thin compared to their breadth, no more than 100 meters
(about 300 feet) thick. To get an idea of their proportions, imagine a ring
as thin as a sheet of paper and about 3 km (2 miles) in diameter.

Seeing that there is so much solar exploration going on, might now be a
time to ask if anyone has actually pinpointed a star yet? I imagine a
distance of several astronomical units should be enough to get a
paralax measurement by now. How far is Saturn; 10?


If you mean "has a deep space probe been used to do parallax
measurements ?" the answer is "no". It's been considered, but so far the
small size of the instruments and relatively low pointing accuracy
outweigh the long baseline. Of course, measurement from Earth orbit has
been revolutionised by HIPPARCOS and GAIA should be a similar advance
over HIPPARCOS.

To answer your question about "how can you see...".

You can't. When Saturn's rings are edge-on, you can't see them...


"Nightshift" wrote in message
...
Has the Cassini probe led to an accurate figure for thickness of Saturn's
rings yet? The estimates vary widely even in relatively modern textbooks.
I've heard that they may be only 30 feet in maximum thickness. Hard to
believe that something so thin can be seen right across the solar system.

Jonathan Silverlight wrote:
In message .com,
Weatherlawyer writes

Seeing that there is so much solar exploration going on, might now be a
time to ask if anyone has actually pinpointed a star yet? I imagine a
distance of several astronomical units should be enough to get a
paralax measurement by now. How far is Saturn; 10?

If you mean "has a deep space probe been used to do parallax
measurements ?" the answer is "no". It's been considered, but so far the
small size of the instruments and relatively low pointing accuracy
outweigh the long baseline. Of course, measurement from Earth orbit has
been revolutionised by HIPPARCOS and GAIA should be a similar advance
over HIPPARCOS.

So the stellar distances are just as hypothetical as their heat source?

And yet interferometry has deduced the Jupiter sized planets of some
stars or doubles or whatever they are called. Or is that to do with
oscillations too, not actual geometry?

In message . com,
Weatherlawyer writes

Jonathan Silverlight wrote:
In message .com,
Weatherlawyer writes

Seeing that there is so much solar exploration going on, might now be a
time to ask if anyone has actually pinpointed a star yet? I imagine a
distance of several astronomical units should be enough to get a
paralax measurement by now. How far is Saturn; 10?

If you mean "has a deep space probe been used to do parallax
measurements ?" the answer is "no". It's been considered, but so far the
small size of the instruments and relatively low pointing accuracy
outweigh the long baseline. Of course, measurement from Earth orbit has
been revolutionised by HIPPARCOS and GAIA should be a similar advance
over HIPPARCOS.

So the stellar distances are just as hypothetical as their heat source?

And yet interferometry has deduced the Jupiter sized planets of some
stars or doubles or whatever they are called. Or is that to do with
oscillations too, not actual geometry?

You're either a troll or terminally stupid (they aren't exclusive).

Other people have told you that measurement of stellar distances by
trigonometry was first done in the 19th century, and even the first
measurements were fairly accurate over a few light years.
The best measurements are now done from space, and as well as the two
missions I mentioned the Hubble Space Telescope Fine Guidance Sensor has
been used.
But the galaxy is so big and the angles are so small that only a few
thousand stars have been measured with more than 10% accuracy. GAIA will
do better - here's a quote from the web site
http://www.esa.int/esaSC/120377_index_0_m.html

"Final accuracies of 10 microarcsec at 15 mag, comparable to measuring
the diameter of human hair at a distance of 1000 kilometres, will
provide distances accurate to 10% as far as the Galactic Centre, 30 000
light-years away."

Now please go away and read something about how exoplanets are detected,
as you clearly don't know anything about that either.

BTW, the heat source of stars is well understood.

Blimey , with jargon like that I'll give the gcse Astronomy course a
miss and stick to fishing.
Dave B