|
|
 |
Imaging Diary - Cassini
Newsroom - Press Releases
Home - Captain's Logs
Newsroom - Looking Ahead
| |
| Rev125 - Jan 15, 2010 | | | ... including Methone, Telesto, Pallene, Epimetheus, and Janus. Over the next two ... will image a transit of Janus by Epimetheus when Cassini is 2.16 million kilometers (1.34 million miles) from Epimetheus. ... |
|
| |
| Rev112 - May 29, 2009 | | | ... rings as the shadows of Daphnis, Epimetheus, and Enceladus cross the rings. ... ISS will observe the shadow of Epimetheus fall across the Saturnian ring ... observation of Pandora, Pan, Pallene, Epimetheus, ... |
|
| |
| Rev 53 - Nov 27, 2007 | | | ... orbit includes flybys of Titan and Epimetheus and numerous observations of Saturn’s ... December 3, Cassini will fly by Epimetheus at a distance of 8,711 km (5,412 ... 2004. At only 114 km (71 mi), ... |
|
| |
| Rev124 - Dec 31, 2009 | | | ... will image a transit of Janus by Epimetheus, when Cassini is 2.12 million ... kilometers (1.32 million miles) from Epimetheus. Unlike most mutual events, when ... Over the next few days, Janus and ... |
|
| |
| Rev121 - Nov 10, 2009 | | | ... Pandora as it partially occults Epimetheus. Next, ISS and UVIS observe a ... the co-orbital moons Janus and Epimetheus across the disk of Rhea. ISS ... small, Saturnian moons: Pallene, Epimetheus, ... |
|
Alliance Member Comments
Shadow on Bright B Ring |
thetonster 2009-07-29 20:59:36 | View all member's comments | Carolyn, PIA11544, or Cas5689-13230-2 seems to show a brightening in the widest part of Epimetheus’ shadow. I don’t recall any through-holes in any pictures of that little ice ball, nor did they reveal it to be washer-shaped. Pray tell, how can a shadow behave this way? Is Epi the same angular size as the Sun just now, and therefore this becomes an interior diffraction spot? It is mighty intriguing. | |
Epimetheus' Shadow |
mipsandbips 2009-07-10 19:06:52 | View all member's comments | Compared to the image "Groundhog Day on Saturn" (image 3/23/09),
the elapsed time between the capture of these two images is about
19 weeks. The camera angle view here in contrast to that image is
a difference of 86 degrees. Revisiting the "Groundhog Day" photo
reveals a very thick and dark shadow of Epimetheus across the A ring
taken on 1/8/09 which was below the ring plane. Here,
at the above angle ring plane view, the shadow cast onto the A ring
is much lighter, thinner and narrow and stretches further towards the
Encke gap than the image in "Groundhog Day". | |
Profile of Janus |
3488 2008-08-14 06:51:30 | View all member's comments | Great image.
Saw this once before as a shadowy noisey raw image. It's great to see that some of the smaller moons are also being researched like Hyperion, Janus, Epimetheus, Helene, Telesto, Phoebe, etc.
Wonder if Janus is like Epimetheus, an icy rubble pile held together by gravity?
Does anyone know when the Helene encounter will be? Is there any chance of a close passes of Calypso, Telesto (again) Polydeuces, etc?
Andrew Brown. | |
Coming to Light |
3488 2008-02-27 17:24:34 | View all member's comments | Hi DEChengst,
I agree with you about the nonsense regarding the Plutonium issue regarding Galileo & Jupiter. I was aware of certain elements against that plan for the fear of Jupiter becoming a second Sun due to Galileo's RTG.
It was total nonsense back then as it is nonsense that Cassini will do that with Saturn.
Gort asked a good question as he / she was not probably not aware of the non issue involved, perhaps heard scare stories from somewhere.
I responded saying that Cassini cannot initiate thermonuclear synthesis within Saturn. Cassini will not last more than seconds after atmospheric entry, will be incinerated as a shooting star in Saturn's highest atmosphere.
I was aware that Pu238 is the wrong isotope for nuclear fission. It is the heat from its natural decay that is powering Cassini. It is not even a nuclear reaction at all & that the RTGs are NOT nuclear reactors.
Remember the nonsense about the campaign to abandon the Earth encounter post launch, due to unjustified panicking over Cassini re entering Earth's atmosphere
Thanks Carolyn,
I was not aware that even the first mission extension was not yet approved. I am sure & hope that it will be granted. The second one should also.
I agree with you 100%, that the Kronian Solstices would be of very scientific value, if Cassini is still operational & controllable then.
Like the recent Janus & Titan images. Although still iregular in shape, Janus appears more 'regular' than co-orbital / orbital swap mate Epimetheus. Wonder if Janus's larger size & mass are responsible.
Primary mission still up & Cassini still performs as well as when had just arrived. I am sure mission extension will happen.
Andrew Brown. | |
Epimetheus Revealed |
3488 2008-02-03 11:59:29 | View all member's comments | Most of these smaller moons appear to be 'rubble piles' of ice & maybe rock. Epimetheus, Janus, Hyperion, Telesto, Calypso, Polydeuces, Helene, etc.
Phoebe appears to be more coherent, but then Phoebe most likely formed elsewhere, maybe the Kuiper Belt, got ejected & then captured by Saturn later on.
The other smaller Saturn moons & Jupiter's Amalthea, appear to be rubble piles held together by gravity. | |
Epimetheus Revealed |
Red_dragon 2008-01-25 15:50:34 | View all member's comments | Yes, it may be so; I think now I can see the crater. It's a luck for Epimetheus to be a porous, low-density body: if it was solid, surely it would have been destroyed. | |
Sixty for Saturn |
Andrzej Karon 2007-07-21 09:41:18 | View all member's comments | Some other interesting facts about S/2007 S4...
===============================================
I can't found at the Web any information about visual brightness of S/2007 S4, but from estimation of diameter, albedo and brightness of neigbouring moons: Methone & Pallene - I thinking so S/2004 S4 has only a. +26.0 mag of visual brightness (= 100 million times fainter than the faintest stars visible to naked eye).
For comparison: Saturn's brightness (at opposition) is about 0.7 mag, so S/2007 S4 is shining fainter by about 25.3 mag. The corresponding difference in brightness is over 13 billion times!
This moon is in elliptical prograde orbit (eccentricity e = 0.0010) with a semimajor axis a = 197,700 km. At pericenter (closest to the planet) S/2007 S4 is separated from the Saturn a distance of q = 197,502 km. At apocenter (furthest from the planet) this moon is separated from the Saturn a distance of Q = 197,898 km.
Angular diameter of the Saturn's disc as observed from this moon is over 35 degrees! (or 70 The Moon's discs). Maximum brightness of the planet as observed from S/2007 S4 is -18.4 mag!
Whereas, this moon as observed near the planet (Saturn hasn't solid surface), has only 3 arcsec od diameter and +7.0 mag of brightness. Future astronauts from this place, can't see this moon! :)
And last interesting fact. These three little moons: Methone, S/2007 S4 and Pallene they have similar rotation periods - quite over 1 earthy day. Therefore the closest approach of S/2007 S4 and Pallene is possible every 10,3 days (i.e. synodic period of these moons), but the closest approach of Methone and S/2007 S4 is more rarely: only every 41,1 days!
BTW: The absolute record holders of the lenght of synodic period are Epimetheus and Janus (over 1400 days or almost 4 years!)
Yours Sincerely
Andrzej Karon
http://ksiezyce.republika.pl/index_en.html | |
 
|
