Rev 120-121 - Oct 23-Nov 30, 2009 - Enceladus E7, E8 Options

[paxdan]

BBC coverage

[Spin0]

Hi!

I have a video on the works, and while working on it I noticed something quite amazing (well, to me anyway - could be old news to you folks here).
Those streaks in the plume images do not look like random cosmic rays, as they go on image by image. I think they are particles. Visible ice particles from the plumes. Beautiful!

For example compare these two beauties:
http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=207371
http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=207372

Ok, news to me, maybe old news to you. Still amazing to see them passing by Cassini.

(still removing stripes, five more images to go, going carpal... sleep now and video ready in 10 hours. )

[ugordan]

Those streaks are stars in the background, Spin0. Other pixels which don't "move" between frames are hot pixels with abnormally high dark current rates - due to cosmic ray damage. The rest is your typical cosmic ray hit stuff.

[Spin0]

Sorry for the false alarm then, and thank you for the quick reply. I really have to get some sleep now.

Yet, have a look at this:
http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=207373
What are we seeing here?

[ugordan]

I see two long star streaks and the rest are hot pixels and cosmic ray hits. The latter can also take on appearance of streaks if the hit is at an oblique angle. Not very common, but it does happen, especially during long exposures like that one. Typically, such artifacts are very sharp, i.e. one pixel can be completely saturated while the adjacent one completely dark, but with real objects, camera's point spread function tends to blur point sources slightly. Hard to notice in compressed jpegs, but more noticeable in calibrated images. Note for example how the star streaks have a certain softness to them.

[HughFromAlice]

This one[/url] has left me almost unable to use whole words. Wow!!!

I've been so busy I somehow forgot to keep up with all this. I dreamed of images something like these when I was a kid reading science fiction - and now they are for real! And the image makers of UMSF have done a nice job too!!!

Thank god for skeet shooters. As for whole words, these came into my mind....

The cloud-capp'd towers, the gorgeous palaces,
The solemn temples, the great globe itself,
Yea, all which it inherit, shall dissolve,
And, like this insubstantial pageant faded,
Leave not a rack behind.

We are such stuff as dreams are made on;
and our little life is rounded with a sleep.


Prospero in the Tempest (PS Vaughan Williams did a wonderful job putting this to music).

[Stu]

Well done Emily, on having your Enceladus image used as today's APOD!

[HughFromAlice]

Yes, well done.

[scalbers]

For some reason this makes me think of some type of interplanetary ski resort with all the snow guns going at full blast.

In terms of the ground track it may be less relevant for this flyby. Being at a relatively large distance (1600km) the individual plume sources may have merged by the time they reach Cassini's altitude. On the other hand plotting the ground track of the Nov 2nd 102.7km flyby on the Nov 21 images might be of some interest if we can assume the plumes are constant enough on that time scale.

Steve

[rlorenz]

For some reason this makes me think of some type of interplanetary ski resort with all the snow guns going at full blast.

Spectacular images indeed. Well done ISS team!

The Enceladus/snow cannon analogy has been brought up before. I was doing the night-ski
thing at Whitetail (PA) earlier this year and they had the snow guns going. I was moved to
send the attached text message to a friend who was meteorite-hunting in Antarctica at the time

snow guns blast the night
Curtains of ice dust rain down
like Enceladus

[sgendreau]

Haven't seen this image here yet, and it's wonderful:


http://ciclops.org//view_media.php?id=29884

from

http://ciclops.org/view_event/120

[ngunn]

Post 102?

But more recently we have this one, in which the plumes are visible against the night side as in the spectacular narrow angle shots:
http://saturn.jpl.nasa.gov/multimedia/imag...5/W00061616.jpg

[sgendreau]

Oops. (smacks head) Sorry, y'all.

[Ron Hobbs]

That famous oblique view of the lunar crater Copernicus was dubbed by some as the "Picture of the Century." When I show it in my presentations, I tell my audience that they might well see the picture of this century before it is all over. But I really didn't believe it; while we have seen some really cool pictures, the century is awfully young.

But this has got to be a candidate for THE Picture of the 21st Century. (Congratulations Emily.)

Looking at the pictures from this encounter, I remembered an exclamation uttered during one of the Voyager encounters of the Saturn system almost 30 years ago. I clipped the following picture and quote, I think from the San Francisco Chronicle:



I attribute this quote to Ed Stone, though I am unable to document it with anything other than my memory. Any way, I share it, in part to celebrate that we are still looking for the unimaginable. It is a kind of crude attempt attempt to do what Asto0 and others do here regularly. (That is Mimas, in case anyone can't make it out.) We certainly have come a long way!

Oh yeah, and we are coming up on the 30th anniversary of Saturnian exploration.

Thanks again to all involved for such incredible views.

Ron

[stevesliva]

Oh yeah, and we are coming up on the 30th anniversary of Saturnian exploration.

Incidentally, the lighting required for such a view will likely not be seen by any other camera for at least 30 years. I am betting that nothing will be there in 15. (And is the lighting equivalent then, at the next solstice? Or is it 30 anyways?)