Oxygen envelops Saturn's icy moon Dione

Scientists say that instruments aboard the Cassini spacecraft have detected a thin layer of oxygen around one of Saturn's icy moons, Dione .
They say the layer is so thin that they term it as an exosphere rather than an atmosphere .

But the discovery is important because it suggests there is a process at work around the solar system's gas giants, Saturn and Jupiter, in which oxygen is released from their icy satellites.
It seems that highly charged particles from the planets' powerful radiation belts split the water in the ice into hydrogen and oxygen.

Dione's sister moon, Enceladus is thought to harbour a liquid ocean below its icy surface. The same is thought to be true of Europa, Callisto and Ganymede which orbit Jupiter.

Prof Coates is among a group of scientists lobbying the European Space Agency to send an orbiter to explore Jupiter's icy moons - known as the Juice mission.
"These are fascinating places to look for signs of life," he said.
As is Titan, Saturn's largest satellite. Its nitrogen and methane atmosphere is reminiscent of the early Earth, according to Prof Coates.
"It may be an Earth waiting to happen as the outer Solar System warms up," he said.
www.bbc.co.uk...

How long till we discover life in our own back yard ? , I know this probably isn't it but I do feel its getting closer almost by the day

Multiple generations of fractures are visible here. Numerous fine, roughly parallel linear grooves run across the terrain from top to bottom and are interrupted by the larger, irregular bright fractures. In several places, fractures postdate some deposits in the bottoms of craters that are not badly degraded by time. Such a fracture, for example, runs from the center toward the upper right.

Most of the craters seen here have bright walls and dark deposits of material on their floors. As on other Saturnian moons, rockslides on Dione may reveal cleaner ice, while the darker materials accumulate in areas of lower topography and lower slope (e.g. crater floors and the bases of scarps).
Dione

Excellent post, thanks for sharing.
It is exciting to think we could be watching the birth of another liveable planet. And just think of the view!
If you could live there, every day you could look up and see the rings of Saturn.

Originally posted by gortex
How long till we discover life in our own back yard ? , I know this probably isn't it but I do feel its getting closer almost by the day

Good post! S&F!
And, yes, exactly my thoughts. IMO, we won't have to wait ten years. Almost everyday bring us good news and strong clues about life outside our Earth.

Very interesting Dione has an exosphere S&F. it was my understanding that the Earth Moon was too small/ light to be able to hold onto it's atmosphere. how then can Dione when it is a third of the size of the earth moon support an exosphere? Before you say well it must be denser, its not. its mass is only 1.5% of our moon's and its a third of the size.

reply to post by RestlessNRG

how then can Dione when it is a third of the size of the earth moon support an exosphere?

That is a good question , but one I can't answer , maybe one of our space experts will chime in with their thoughts
I do have this size comparison chart though .

reply to post by gortex


It could be that the oxygen is being slowly released through the water ice,of which Dione is mostly made of.
Not sure,just a guess.

Edit:Maybe any space rocks that hit Dione seperate the oxygen and hydrogen as they hit the surface-but then there would likley be twice as much hydrogen in the moons exosphere...
Hmmm..

The ion charge from Saturn's electromagnetic field is pelting down on Dione as it is close and right in the mist of these fast moving subatomic particles, believed to be separating the oxygen and hydrogen from the frozen ice. Professor Coates has been researching ionization in our solar system for decades and has quite a library of papers he's had published in Journals including Nature. He also believes the rings of Saturn are doing much the same thing, emitting oxygen into the magnetic field to eventually be lost to space.

I looked up this chap before work today but didn't have the time to formulate a thoughtful reply, well now at lunch its time to go back to work, so pardon the brevity.

Nice find, I think finding life is closer than we think. Obviously our recipe for life (water) is one of infinite possibilities, and we are finding plenty of water. Our notions of life not existing in extreme conditions has been trumped time and time again from discoveries on earth. deep sea and otherwise- even Bacteria that exists in sulpheric acid! So the life is there, it may not be advanced, but if bacteria exists in our backyard- it makes the possibility of advanced life quite plausible.

It's beautiful science, to be sure. However, talking about "life in our backyard" in this context it premature at best and in my opinion is unfounded, in this particular case. If radiation levels are so high as to cause dissociation of water into its atomic components, H2 and O2, can you imagine what can happen to most any molecule in this environment?

Again, this is exciting news and all, but that would be the last place to look for life in the Solar system. Radiation can be a b!tch.

Originally posted by RestlessNRG
Very interesting Dione has an exosphere S&F. it was my understanding that the Earth Moon was too small/ light to be able to hold onto it's atmosphere. how then can Dione when it is a third of the size of the earth moon support an exosphere? Before you say well it must be denser, its not. its mass is only 1.5% of our moon's and its a third of the size.

I think it's because it's in a really really cold part of the galaxy, a million miles from our hot hot sun. That's why it can hold on to its exo/atmosphere, despite being a light little sphere...I saw this explanation for one of Saturn's other moons on a BBC show about the solar system...

reply to post by buddhasystem


As I said in the OP , I know this probably isn't a sign of life but in my View the emphasis is on probably , it is highly unlikely but the possibility exists .
As we are constantly discovering given on opportunity life will find a way to make the most of the situation it finds itself in , Dione has an ice shell but is believed to have a rocky interior so with the cracks in the ice shell maybe there is a possibility for life beneath the ice .

I believe that when we get our act together and start seriously searching for life we will find it in abundance on the planets and moons in our solar system , OK we won't be able to talk to it but the implication will be obvious

Cool post!

I always love reading articles about the different moons in our solar system. We thought the plants themselves were great, but the moons of the gas giants, wow. So diverse and interesting to read about.

For the sake of conversation, what do you think about``seeding life``. Would it be a good idea to send capsules containing various bacteria, plants etc. To the bodies in our system in order to potentially jump start life there. Or would it be an abomination of nature to do so?

I think there is obviously life out there. Maybe not intelligent life. If there has been other intelligent life out there it must be extraoridinarly difficult to impossible to travel from one Solar system to another even for advanced species. We would have had some evidence by now. An advanced species would have detected and traveld here to investigate Earth if it were easy to travel out there. We Humans could live and go extinct and never know there are millions of other intelligent species out there. Shame we waste so much on wars rather than learning to thrive in outer space.

Originally posted by el1jah
For the sake of conversation, what do you think about``seeding life``. Would it be a good idea to send capsules containing various bacteria, plants etc. To the bodies in our system in order to potentially jump start life there. Or would it be an abomination of nature to do so?

You mean like Terra Forming?

I could see that sparking controversy. You would have those that would say: Leave it alone! who would want it kept the way it was found.
And you'd have others saying: Why not? Let's spread life around.

I think if it were a place that was completely void of it's own indigineous life, that it would be okay. But that's just my opinion on it.

I have new life springing up in my fridge every time I forget about the left-overs!

reply to post by el1jah

post by el1jah
For the sake of conversation, what do you think about``seeding life``.

I don't think we have the right to infect other planets or moons with Earth born organisms , we couldn't say for sure that the body didn't already contain life , we would only recognize life as we understand it whereas an alien life form maybe totally different , maybe silicone based or something even more exotic

Yeah I`m on the fence about it, for what its worth, space is a REALLY big place so the chances of doing real harm are not great, but I dont think we reserve the right to do harm in the first place. Its funny people would be bent out of shape about this, all the while forgetting the devastation we do on our home planet.

How about we create a completely isolated reproduction of the environment of lets say... mars. Then genetically engineer creature that could live there, plants that might lead to creating an atmosphere... then seed the planet! I`m sure whatever is already living there, bacteria or otherwise would adapt in the time it would take to actually pull it off.

But how are we going to know if there is life on these other planets?? Do you think that nasa will actually tell us if there was life on one of these moons?

As the planets migrate inwards towards the Sun, these moons form the ingredients of the worlds that follow them.. truly amazing is this path...

motherearthfathersky.org...

All these amazing places right in our own backyard. Now of course there are no little green men (that we know of) running around on these moons. However if several of these have a liquid ocean beneath their surfaces, or any form of liquid water, the possibilities for life are greatly increased. So lets say Europa or Enceladus not only have the oceans, but the mammals, then why aren't we paying closer attention to them? I mean isn't one of NASA's goals to discover "life" on other planets/moons besides our own? Why is so little attention being paid to these places and so much attention is going to Mars? My theory: What is left for NASA once it does discover life somewhere (assuming they haven't already)? After you find "life" what can they possibly have left in terms of a discovery greater than that? Nothing...at least not right now. Since we don't have interstellar travel, that would be the next thing. Or the discovery of a civilization outside our solar system. My point is, money and resources might be better spent getting something to land on those moons. I would even say for the sake of science.

Anyways great post OP. I love reading about science like this. Flag and star.