Cassini Equinox & Solstice Mission, (nine year extension)!!.

[EarthlingX]

Re: Cassini Equinox Mission (Cassini's two year extension).

Got my computer back, got my software loaded back on.

That's a nice news
Pictures too

Looking at this, i think that erosion was a picture artifact, and that darker lines look like a covered crack .. ?

Could ring particles settle down without making craters ?

That last picture looks as if one layer slided above the other .. ?

 

[EarthlingX]

Re: Cassini Equinox Mission (Cassini's two year extension).

3D rendering of Prometheus :

Behold the Violent History of Saturn's White Whale Moon

(PhysOrg.com) -- Like the battered white whale Moby Dick taunting Captain Ahab, Saturn's moon Prometheus surges toward the viewer in a 3-D image from NASA's Cassini spacecraft.

Saturn's potato-shaped moon Prometheus is rendered in three dimensions in this close-up from Cassini. Image credit: NASA/JPL/Space Science Institute

The image exposes the irregular shape and circular surface scars on Prometheus, pointing to a violent history. These craters are probably the remnants from impacts long ago.

Cassini's narrow-angle camera captured two black-and-white images of the moon on Dec. 26, 2009, and the imaging team combined the images to make this new stereo view. It looks different from the "egg-cellent" raw image of Prometheus obtained on Jan. 27 because that view shows one of the short ends of the oddly shaped moon. In this 3-D image, the sun illuminates Prometheus at a different angle, making the moon's elongated body visible.

Provided by JPL/NASA

I need to get me 3d glasses ..

 

[3488]

Re: Cassini Equinox Mission (Cassini's two year extension).

Hi EarthlingX,

I wondered about posting that myself, be seeing as 3D glasses are required, I decided not to. However, it is very interesting none the less. Looks like ice has fallen to the surface smoothing off the craters & profiles. Wayne earlier suggested impacts shaking down loose material & erasing sharper rims.

We have certainly seen similar on silicate asteroids 951 Gaspra & 433 Eros, where as Prometheus is certainly icy. Principle is exactly the same though.

Andrew Brown.

 

[3488]

Re: Cassini Equinox Mission (Cassini's two year extension).

Below, A Gibbous Iapetus seen from approx 1.5 M KM on: Friday 19th February 2010. Had to be really enlarged, but Iapetus is always interesting & worth the effort. The dark Cassini Regio is clearly visible in the top left.

Andrew Brown.

 

[CalliArcale]

Re: Cassini Equinox Mission (Cassini's two year extension).

I agree -- Iapetus is always worth the effort!

More interesting, though, is the obvious signs of material sliding down the walls of Herschel Crater. It's not an unusual thing to see in pics like these, but it's always exciting because it reminds one that even these apparently "dead" worlds are still quite dynamic.

 

[3488]

Re: Cassini Equinox Mission (Cassini's two year extension).

Hi Calli,

Thank you very much. You are correct, even supposedly 'dead' worlds show dynamicism, Mimas is no exception. This is the one & only closigh pass of Mimas during the entire mission, even including the Solstice Mission & it is most obvious that mission scientists have made the most of this pass of the 395 KM wide ice moon.

Me too. :mrgreen: :mrgreen:

It will be interesting to see the gravity data as Cassini did pass close enough to feel the pull from Mimas. I suspect the undifferentiated ice ball model will be the one that fits, as with Iapetus, Rhea & Tethys. We'll see. :?:

Andrew Brown.

 

[3488]

Re: Cassini Equinox Mission (Cassini's two year extension).

Enceladus Forest of Jets update.

Below, 40 KM section of Baghdad Sulcus.

A few of my crops & enlargements.

Enceladus. 50 KM wide circular feature.

Looking north over south polar region of Enceladus.

Enceladus. Baghdad Sulcus.

Enceladus. Approx 3 KM long section of Baghdad Sulcus.

The leading hemisphere of the 524 KM diameter ice covered, highly evolved moon of Saturn.

Far north of the leading hemisphere of Enceladus. What is most apparent here is young evolved terrain on the left suddenly gives way to much older, cratered terrain on the right. The Ali Baba & Aladin Craters are clearly visible.

Andrew Brown.

 

[EarthlingX]

Re: Cassini Equinox Mission (Cassini's two year extension).

:shock: :shock: :shock:

What about this one ?
Bursting at the Seams


I think that circular feature can be seen in the upper right ?

edit :
Cassini Finds Plethora of Plumes, Hotspots at Enceladus

Newly released images from last November’s swoop over Saturn’s icy moon Enceladus by NASA’s Cassini spacecraft reveal a forest of new jets spraying from prominent fractures crossing the south polar region and yield the most detailed temperature map to date of one fracture.

“This last flyby confirms what we suspected,” said Carolyn Porco, imaging team lead based at the Space Science Institute in Boulder, Colo. “The vigor of individual jets can vary with time, and many jets, large and small, erupt all along the tiger stripes.”

Some of Cassini’s scientists infer that the warmer the temperatures are at the surface, the greater the likelihood that jets erupt from liquid. “And if true, this makes Enceladus’ organic-rich, liquid sub-surface environment the most accessible extraterrestrial watery zone known in the solar system,” Porco said.

 

[3488]

Re: Cassini Equinox Mission (Cassini's two year extension).

Hi EarthlingX,

That is some awesome image. It was also released, not long after the encounter last November.

Below some enlarged crops I have done, rotating them to look like an horizon, as I did with the enlarged crops I did of the limb of Mimas. The bottom one has the curious circular feature forshortened on the terminator.

Talking of the inner neighbour of Enceladus, Mimas, I have done three more enlarged crops.

An area approx 45 KM across on Mimas, showing craters of varying ages on an icy rolling terrain. N E of Herschel Crater.

A large region, approx 250 KM wide to the west of Herschel Crater, that is brighter & bluer than anywhere else on Mimas.

S E Herschel Crater & terrain on the floor of said crater & outside. The striations on the wall of Herschel Crater, owing to landslides are obvious here on Mimas. Area shown is approx 45 KM across.

Andrew Brown.

 

[nimbus]

Re: Cassini Equinox Mission (Cassini's two year extension).

Is there anything about the circular feature that could rule it out as an impact crater?

 

[EarthlingX]

Re: Cassini Equinox Mission (Cassini's two year extension).

Hi EarthlingX,

That is some awesome image. It was also released, not long after the encounter last November.

Yes, i have it already, just rotated by 180 deg, but i'am not sure, would have to rotate it and check.

Below some enlarged crops I have done, rotating them to look like an horizon, as I did with the enlarged crops I did of the limb of Mimas. The bottom one has the curious circular feature forshortened on the terminator.
http://i233.photobucket.com/albums/ee18 ... Nove-2.jpg
http://i233.photobucket.com/albums/ee18 ... ovembe.jpg
http://i233.photobucket.com/albums/ee18 ... Nove-1.jpg

Amazing, thank you

Just in case:

Talking of the inner neighbour of Enceladus, Mimas, I have done three more enlarged crops.

An area approx 45 KM across on Mimas, showing craters of varying ages on an icy rolling terrain. N E of Herschel Crater.
http://i233.photobucket.com/albums/ee18 ... 21Cass.jpg

A large region, approx 250 KM wide to the west of Herschel Crater, that is brighter & bluer than anywhere else on Mimas.
http://i233.photobucket.com/albums/ee18 ... 22Cass.jpg

S E Herschel Crater & terrain on the floor of said crater & outside. The striations on the wall of Herschel Crater, owing to landslides are obvious here on Mimas. Area shown is approx 45 KM across.
http://i233.photobucket.com/albums/ee18 ... 23Cass.jpg

Andrew Brown.

Is there anything about the circular feature that could rule it out as an impact crater?

 

[nimbus]

Re: Cassini Equinox Mission (Cassini's two year extension).

Should've asked more specifically. I meant the circular feature on Enceladus. Third picture in Andrew's last post.

 

[EarthlingX]

Re: Cassini Equinox Mission (Cassini's two year extension).

A few of my crops & enlargements.

Enceladus. 50 KM wide circular feature.
http://i233.photobucket.com/albums/ee18 ... ar50Km.jpg

Looking north over south polar region of Enceladus.
http://i233.photobucket.com/albums/ee18 ... 09Cass.jpg
Andrew Brown.

On the upper part of this picture, is this the same feature, or something else ? Is this that circle with jets ?

Below some enlarged crops I have done, rotating them to look like an horizon, as I did with the enlarged crops I did of the limb of Mimas. The bottom one has the curious circular feature forshortened on the terminator.
http://i233.photobucket.com/albums/ee18 ... Nove-2.jpg
http://i233.photobucket.com/albums/ee18 ... ovembe.jpg
http://i233.photobucket.com/albums/ee18 ... Nove-1.jpg

It is the same, just rotated photo, i think
http://ciclops.org/view_media/29980/Bur ... _the_Seams

Not a crater ?

 

[nimbus]

Re: Cassini Equinox Mission (Cassini's two year extension).

That's the one yep. I'm curious, if it can be ruled out as a crater deformed geologically, what processes native to a body like Enceladus could produce such a round feature.

 

[abq_farside]

Re: Cassini Equinox Mission (Cassini's two year extension).

Truly fascinating images - thanks to Andrew.

 

[3488]

Re: Cassini Equinox Mission (Cassini's two year extension).

Thank you very much EarthlingX, nimbus & abq_farside for your input, questions & supportive comments about my work on here. I really do appreciate them very much. :mrgreen:

Hi nimbus,

Re: that curious circular feature on Enceladus. IMHO, it is an impact feature. I reckon a bolide punctured thin ice & the 'roundish' hole out gassed then froze over. The concentric internal ridges to me, suggests that the ice refroze from the outside in. I reckon that the feature is very, in fact extremely geologicaly young, maybe only a few million years old. To me it does not look cryovolcanic, rather an impact feature.

Three more efforts I have worked on. Like yesterday's I have rotated the first two to look like a horizon.

Below a crescent Enceladus, with the south polar geysers visible, with the limb of Saturn to the lower left. Enceladus was closer to Cassini then Saturn.

I have enlarged, sharpened & contrast enhanced this image. It came out quite well I think.

Iapetus again, Monday 22nd February 2010. 1.48 M KM. Cassini Regio has rotated further into view.

Andrew Brown.

 

[3488]

Re: Cassini Equinox Mission (Cassini's two year extension).

Iapetus again, this time from 1.60 M KM on: Tuesday 23rd February 2010. Some large craters in the southern hemisphere have rotated into view, as has more of Cassini Regio.

On Wednesday 24th February 2010, Enceladus passed behind Dione as seen from Cassini. A few of my enlarged crops of said event.

Andrew Brown.

 

[EarthlingX]

Re: Cassini Equinox Mission (Cassini's two year extension).

:shock:
Can't help it, this passes always leave me searching for my jaw under the table, it's good i don't need it to type .. :roll:
Khm..

Re: that curious circular feature on Enceladus. IMHO, it is an impact feature. I reckon a bolide punctured thin ice & the 'roundish' hole out gassed then froze over. The concentric internal ridges to me, suggests that the ice refroze from the outside in. I reckon that the feature is very, in fact extremely geologicaly young, maybe only a few million years old. To me it does not look cryovolcanic, rather an impact feature.
Andrew Brown.

Just a thought : Could it then tell us something about the crust thickness and layer densities ? To me it looks like a puffy cover over a bit harder crust over liquid interior ? Like a snow on a frozen lake ?

 

[3488]

Re: Cassini Equinox Mission (Cassini's two year extension).

Hi EarthlingX,

Could be, but it could also be evidence that the crust in that area is thicker than is thought, by the fact that it appears as though there is no activity within the feature. The concentric rings can be explained by compression as it refroze & the ice expanded.

Cassini during the Solstice Mission will pass by Enceladus 12 times, & on at least two of them will pass close by above the south polar region after the Sun has set over this region. It will be interesting to see if the plumes are still active then. If not then it is more likely that the source of the plumes is close to the surface & is likely to be venting as a comet.

If they still remain active & strong, then it increases the possibility of bodies of liquid water under the surface, being kept 'warm' by the tidal frictional heating with Saturn on one side & Tethys & Dione on the other.

On Wednesday 3rd March 2010, Cassini passes approx 1,800 KM from Helene, the 36 x 32 x 30 KM sized leading Dione Trojan moon.

Some images of Helene from earlier on in the mission from much greater distances.

Three views with the final one overexposed to show the night side lit by Saturnshine.

Andrew Brown.

 

[3488]

Re: Cassini Equinox Mission (Cassini's two year extension).

Hotei Arcus on Titan IS a cryovolcanic feature on Titan.

Hotei Arcus cryovolcanic flows.

Hotei Arcus minerals & channels.

Andrew Brown.

 

[EarthlingX]

Re: Cassini Equinox Mission (Cassini's two year extension).

Hotei Arcus on Titan IS a cryovolcanic feature on Titan.

Hotei Arcus cryovolcanic flows.


Hotei Arcus minerals & channels.


Andrew Brown.

Could we see it a bit closer and bigger ? :roll:

 

[marsbug]

Re: Cassini Equinox Mission (Cassini's two year extension).

Cassini during the Solstice Mission will pass by Enceladus 12 times, & on at least two of them will pass close by above the south polar region after the Sun has set over this region. It will be interesting to see if the plumes are still active then. If not then it is more likely that the source of the plumes is close to the surface & is likely to be venting as a comet.

If they still remain active & strong, then it increases the possibility of bodies of liquid water under the surface, being kept 'warm' by the tidal frictional heating with Saturn on one side & Tethys & Dione on the other.
.

The south pole is putting out more heat than it gets from the sun, so don't the vents have to be internally driven?

 

[EarthlingX]

Re: Cassini Equinox Mission (Cassini's two year extension).

Picture from the latest pass, there are more ... :

W00063094.jpg was taken on March 01, 2010 and received on Earth March 02, 2010. The camera was pointing toward ENCELADUS at approximately 912,043 kilometers away, and the image was taken using the CL1 and CL2 filters.

For a quick refresher, i'am not sure how much related to the above picture, a couple of 'older' 'tiger stripes' pictures:

Baghdad Sulcus in Context -- Annotated:


Enceladus' Warm Baghdad Sulcus


Zooming in on Heat at Baghdad Sulcus


My non-scientific contribution cut from PIA11696: Enceladus' Warm Baghdad Sulcus

 

[EarthlingX]

Re: Cassini Equinox Mission (Cassini's two year extension).

A couple of fly-bys :
Rhea Flyby (R-2) - March 2, 2010

Return to Rhea

Cassini swoops down to within about 100 kilometers of Rhea to “sniff” the moon. Particle and fields instruments will try to determine what is coming off Rhea. The last targeted flyby of Rhea happened in November 2005.

Helene (Quasi-targeted) Flyby - March 3, 2010

Helene Quasi-targeted Flyby

Following a day after a targeted flyby of the moon Rhea, the Cassini spacecraft makes its closest approach of the mission to Helene at about 1,800 kilometers (1,131 miles). The small moon is referred to as a trojan moon because it is gravitationally tied to the much larger moon Dione.

 

[3488]

Re: Cassini Equinox Mission (Cassini's two year extension).

Just a very quick chime in.

Thank You very much EarthlingX for your excellent posts. I like your crops, I'l ldiscuss with you later, it's fascinating stuff.

First Rhea images coming in now. These are just direct links to raw images so may not be orientated correctly.

From approx 19,700 KM.

From approx 14,300 KM.

From approx 13,840 KM.

Approx 24,110 KM. WAC.

In approx 2 hours, closest approack to Helene.

Andrew Brown.