Hi all,
August 11th is equinox time on Saturn, this means its 200000 mile wide 1/2 mile thick ring system is edge on to the Sun and that the rings will be in their own shadow so making them disappear.

www.astromart.com/news/news.asp?news_id=975
Only problem is Saturns proximity to the sun, so maybe catch it soon before sunset is the way to go. hopefully it'll be clear, this would make for a very interesting event to see.

Thanks for posting Dave.

I thought it was September 4th this was to be 'official'?

Seanie.

Hi Seanie,
On Sept 4th, the rings are edge on as seen from Earth.
On Aug 11th, the rings are edge on as seen from the Sun so they would be invisible from anywhere in the solarsystem, maybe Saturns globe could provide some dim illumination, who knows.
It'll be interesting to see if Cassini images this.!

If rings are not edge on with respect to Earth but are edge on with respect to Sun and assuming that only edge is illuminated (both top-side and under-side of plane of rings not illimuninated) then surely the rings would appear black against the surface of the planet (as they are not edge on to us).

It is possible though that the size of this view might be so small that they can't be seen from Earth. I can, however, imagine the "ears" becoming invisible to us.

Regardless of any truth or error in my visualisation of this it would be nice if this was captured somehow.

Mark

Dave_Lillis wrote:

On Aug 11th, the rings are edge on as seen from the Sun so they would be invisible from anywhere in the solarsystem

...as seen along the ecliptic (plane of the Sun)?

yip!
how cool is that

Whatever the view from Earth it appears that Cassini has already detected a new moonlet and may find more due to their "long" shadows across the ring systems.

This implies to me (with confusion still present) that some illumination will still take place (I infer this from second reference below).

Interesting times and Cassini being our "Correspondent From Saturn" to report on the event:)

news.bbc.co.uk/2/hi/science/nature/8194093.stm

saturn.jpl.nasa.gov/news/newsreleases/newsrelease20090807/

Mark

mjc wrote:

This implies to me (with confusion still present) that some illumination will still take place (I infer this from second reference below).
Mark

You've got a 75 thousand mile wide illuminated planet behind the rings, that is going to provide some light, the same way the astronauts shadows on the moon weren't completely black, the surround area illuminated them.
Also, the moons might be several hundred meters or several kilometers wide, wider then the rings, so they could end up been wider the width of the shadow cast by the rings, so catching some Sun.

Tried to observe this last night and tonight...
Clouds.
Bah.
Any luck anyone?

The Cassini images around equinox have been received.

This raw uncalibrated image (taken on 13th Aug) shows the contrast between bright planet and darkness of ring plane at that time.

saturn.jpl.nasa.gov/photos/raw/rawimaged...x.cfm?imageID=198568

Mark