Rev 181, Titan encounter and propeller searches Options

[jasedm]

This revolution is now in full swing, with a Titan encounter (Cassini's 90th!!) on the 17th.
In the meantime, some great raw images of a very dynamic F-ring are available This sequence also shows prometheus, pandora and I think, Pan in some of the shots.

The F-ring orbits (commencing late November 2016) should be amazing, as there'll be images at 10-times the resolution of these.

Also a great shot of Enceladus eclipsing the rings here

What a ride!

[kemcab2012]

Earlier this evening I uploaded a video based on the F-ring study sequence. It's running at around 5 fps. It's the raw photo footage, just adjusted frame by frame to keep this in relative sync.

**Edited the text under the video a bit for a mistake resulting from being rather tired.

[kemcab2012]

Uploaded another video, this time of the Valentine's Day study of the A-ring's propellers. The big thing that sticks out are the particles in the Encke gap. However, I recommend watching the video in 720p with full screen viewing. Do that, and you can see the minor fluctuations in size of the many propellers there. Again, this is running at a perceived 5 fps.

So beautiful.

***Edit: Created and uploaded a 1080p version.

[jasedm]

Thanks Kemcab

Lots of activity in the Encke gap ringlets; and Daphnis + wake disturbances in the Keeler gap flash through the FOV at 0.12. I don't see any propellers in the A-ring though...

Very nice!

[kemcab2012]

I was completely misusing that term - my apologies.

Two questions: is that a propeller or cosmic ray at the .32 mark, below absolute center of the image? Also, what is the bright object passing outside the Encke gap during .1?

[jasedm]

Almost certainly cosmic-ray hits or noise - very easy to 'see' things in the raw images that are spurious - I'm a past master at that myself

Meantime, a very distant view of Pan cruising/carving-out the Encke gap. (You'll have to squint to catch it centre-ish of frame....)

Cassini dives down through the ring-plane within 25,000km of Pan in 4 years time, it would be fantastic to see this little clump of debris up-close.

[jasedm]

Previously-spotted propeller confirmed on this orbit - unofficially called Bleriot (geddit?)
It's the white smudge between the Encke gap (left) and the Keeler gap (right)

The other prominent propeller spotted back during equinox was 'Earhart'

These moonlets (or clumps) aren't actually resolved in the images, only their gravitational effects in the A-ring, but the consensus seems to be that they're in the order of a few hundred metres across - i.e 10+ times the diameter of the recent Russian meteor.
It gives an idea of the immense scale of the Saturnian ring system.

[kemcab2012]

I saw this today - great stuff! I have a question, going back to the shots taken during 181. What is the white dot just to the right of Encke gap that starts here (N00202334) and continues to here (N00202339), rotating within the ring.

I could be wrong, but it looks like Bleriot was captured again in the latest shots.

[volcanopele]

that is a propeller, not sure which one, but that's definitely not Bleriot. Too far in. Look at the banding in the outer A ring in the two image sets.

[kemcab2012]

But when I put the images side by side, they appear to line up pretty well, when taking angle of the shot, distance, etc. into account.

[volcanopele]

See, that's what I get for not clicking the link, I thought you were talking about the one in N00202334-N00202339, which I think is either Earhart or Post... most likely Post since I think Earhart is about the same size as Bleriot.

But yeah, that one there is Bleriot.

[jasedm]

Good catches Kemcab.

Also, perhaps Bleriot is on the cusp of becoming (through accretion of ring particles) massive enough to carve itself a new gap in the A-ring. Looking up and downstream of the body in PIA14649, there seems to be a partial clearance of ring material a few degrees either side of it.

Very interesting!

[kemcab2012]

volcanopele: No problem! Looking back at my post, I should have made clear that I was referencing a different set of imagery.
jasedm: Thanks! I upped the contrast on the PIA image and cropped it to Bleriot's area:



Yeah, there's definitely some clearance around it.

[kemcab2012]

I went back to the November 11th, 2012 A-ring sequence, downloaded the images, made a movie from it, and rotated it to match the direction and view of the sequence captured on Valentine's Day. I also updated the Valentine's Day A-ring sequence to include the images that came after I created it.

November 11th, 2012, Rev 174 A-Ring Sequence

February 14th, 2013, Rev 181 A-Ring Sequence - Complete

Note Daphnis at the :50 mark and Bleriot at 1:00 in the November video.

[kemcab2012]

Also, here's an animation from Cassini's WAC as it passed by Enceladus on February 14th.

**Edit: Feb 27 - Another five frames just popped up on Cassini's raw image site. Added them to the animation, cropped the image to cut off the missing edging and excess, and replaced the above image with the updated version.