First water plume seen firing from Jupiter moon Europa | Hacker News Reader

First water plume seen firing from Jupiter moon Europa

newscientist.com

91 pointsFletch13750 comments

For those expecting to see an actual image, this is the closest thing to a photo from NASA: http://www.nasa.gov/content/goddard/water-vapor-over-europa/

They note: "Hubble didn't photograph plumes, but spectroscopically detected auroral emissions from oxygen and hydrogen."

Full press release from NASA: http://www.nasa.gov/content/goddard/hubble-europa-water-vapo...

For an amazing photo of Europa with Io's volcanic plumes in view, see this older photo from 2007: http://photojournal.jpl.nasa.gov/jpeg/PIA10103.jpg

Full description here: http://photojournal.jpl.nasa.gov/catalog/PIA10103

does this mean it's pure conjecture that it was a water plume? my idea of a water plume would say that it's sub surface ocean water getting ejected out of the surface. this evidence seems like it could have been water knocked up by a meteor impact or some other mechanism to get the surface ice into orbit.

it's my understanding that the gravitational "torsion" from Jupiter alone is enough to do all sorts of things (like keep a planet thermally active)

Please forgive my ignorance. What makes Europa more likely to contain life than other moons thought to contain oceans like Callisto, Ganymede, Titan, Enceladus ... ? [1]

[1] http://img.gawkerassets.com/img/18lqil4sqeremjpg/original.jp... [2]

[2] http://io9.com/5827649/a-map-of-all-the-water-in-the-solar-s...

And this is why NASA's Planetary Sciences division should not suffer huge budget cuts.

Enormous oceans of liquid water, with internal tidal heat and protection from harsh surface environment?

And lets not forget the large black monolith.

All joking aside, the guy who wrote those kind of knew what the hell he was talking about.

Absolutely!

read the 2010 novel by authur clarke. he goes into some detail about how it might work

I believe there's more evidence for an ocean in Europa than the other Galilean moons, and the ice sheet on top is thought to be substantially thinner. As for the moons of Saturn, I suspect Enceladus gets less interest simply because it's far less accessible, and if Titan has life it won't be remotely like any sort of life we're used to, and may be quite difficult to detect.

Because modern science is Eurocentric? :p

Titan is known to contain oceans, but of nearly cryogenically cold hydrocarbons. It's unlikely to support life merely due to the temperatures there.

Many planetary bodies are thought to have sub-surface water oceans of some variety, though Europa's is the most intriguing for several reasons. Given that Europa's surface is entirely water ice and geologically quite young that is a strong indication that Europa's sub-surface ocean is vast, warm, and consistently liquid over geological time periods. If, for example, Ganymede's ocean were as large and as warm then why has it not risen to the surface and formed an ice layer? This is backed up by the fact that Europa experiences an intense amount of tidal heating from it's galilean moon neighbors.

Because of this high amount of tidal heating, which on the neighboring moon Io is sufficient to cause widespread vulcanism, there is a reasonably good chance of significant hydrothermal vent systems within the Europan ocean. We've found on Earth that such vents can support chemotrophic life (through sulphides and serpentinization) which can support complex ecosystems which include animals such as shrimp and clams.

That isn't to say that other bodies may not harbor substantial sub-surface oceans or support extra-terrestrial life, but the case for Europa is that much stronger and so that much more a compelling target for investigation.

This is an awesome phenomenon. Yesterday we had a post re panspermia:

https://news.ycombinator.com/item?id=6888412

Now think of an Europa with simple bacteria living in the water under the ice. These events are like cosmic sporulation: long strings of frozen droplets that could contain organisms, ejaculated into space like spores in the wind.

I'm (existentially/cosmically) aroused!!

And promptly sterilized. Unfortunately most plausible life forms require meters of soil/rock surrounding them to survive the harsh space environment (probably more in the vicinity of Jupiter).

We're finding extremophiles in all sorts of places we didn't expect. Radiation-resistant bacterial spores are hardly outside the realm of possibility - we've already found some.

Yes, but context. They're not likely to have evolved inside the relative oasis of Europa's oceans (or put differently, they're not likely to have retained any extremophile traits they might have once had).

Some water is clearly getting to the surface. If there's life, at least some of it is being exposed to decent levels of radiation.

You obviously didn't read anything about the research. The analysis was focused on the likelihood of large chunks of rock being ejected during an impact, large enough to provide sufficient protection from the interplanetary radiation environment for geologically significant periods of time.

While I am not a biologist myself, I did work 2 years at the NASA Astrobiology Institute in a supporting role, where I learned all about the science surrounding this stuff. I don't know any astrobiologist who seriously believes that whatever microbes might exist in the comfort of Europa's inner ocean might survive free-floating in the harsh Jupiter radiation belts, where it takes hours or days (not millions of years) to sterilize all but the most extreme life forms.

"Jupiter radiation belts"

Found "Magnetosphere of Jupiter" on Wikipedia and it looks like the rest of my evening will be spent on this little tidbit. How could I never have heard about this.

Which is why it's far from a sure thing, only a possibility. However, if an object impacts Europa directly from a heliocentric orbit it won't spend much time in Jupiter's radiation belts. With enough luck maybe it would hit just the right patch of Europa to be captured in the ice and make its way down into the ocean without much exposure to radiation. Certainly that's a very unlikely event, as is simply getting a rock containing life from Earth to Europa in the first place. However, the Solar System is very, very old and in such stretches of time unlikely events can and do happen.

Ultimately the possibility cannot be conclusively ruled out, and given the implications it's worth considering.

The GP was about life from the ocean surviving the geyser into space, as "long string of frozen droplets that could contain organisms" in orbit around Jupiter.

Checkout the movie Europa Report to feed your SciFi fantasies.

Second this. Excellent random movie selection on Netflix.

Third it. The movie starts out looking like it's going to be pretty cheesy, but stick with it. This is a unique film.

The entire time I was watching it I felt like they were pissing on Arthur C. Clarke's grave.

If I was an "ocean under an ice layer" based civilization this might be my best way to get an object into orbit.

Was the plume aimed at anything in particular?

The fascinating aspect of your post is that scientifically we continue to think of 'life' as 'life as we know it'

A civilization that evolves completely underwater (and in Europa's case divided from one underwater oasis to the next) might be possible even if it means the absence of fire.

If I take a wild guess (into the next 50 years), we probably will be able to land on Europa. After collecting dirt and water, we found nothing. However, scientists didn't give up on it and debate life could be existed in deep ocean, which is way deeper than what we can go even on Earth. There you go: we have to go far across space and end up swimming really deep. Too many technological barriers. It'd be even more disappointing when we actually find out living organisms, then they look so similar to what we already have on Earth. Again, my "wild guess"

Would be cool if they got there and found layer upon layer of carcasses resembling whales, fish, trilobites ... seasoned with smaller organisms. A record of evolution, deposited over thousands of years of geyser activity, perfectly preserved and documenting every evolutionary bifurcation that ever swam too close to one of these blowholes.

I can dream, can't I?

That's unlikely because ice is fairly dynamic. These geysers are proof that new ice is constantly being formed, and over the timescale needed to see any sort of evolution, the ice layer would have been reformed countless times.

It'd be like finding fossils around Kilauea in Hawaii. You don't because there's new land being formed all the time, and there's not enough time for fossils to be formed.

I imagined that such a geyser has a limited lifespan. Same mechanism as why islands like Hawaii or the super volcano in Yellowstone come in chains. Same thing could be happening on Europa: the icy crust moves and the "hot spot" is fairly fixed. Or a local vent collapses after x years and another weak spot opens. In those scenarios the area surrounding a geyser could preserve a chapter of the planet's history.

As warm as the word vapor may sound it is actually really cold. Europa's oceans, if they exist, are -50°C and lower.

Doesn't water freeze and become ice at 0°C?

Only at one atmoshpere of pressure.

The difference is negligible: http://i.stack.imgur.com/n6LXj.gif

According to this[1] the pressure on Europa is "one hundred billionth that of the Earth". Your graph uses a log scale, so maybe I'm measuring this wrong, but I'm pretty sure under so little pressure, water can be vapor at -50ºC. So the pressure is hardly negligible in this case.

[1]http://hubblesite.org/newscenter/archive/releases/1995/12/te...

You can make supercooled water in your freezer.

http://en.wikipedia.org/wiki/Supercooling

> The process of supercooling requires that water be pure and free of nucleation sites

Good luck finding distilled water with no contact with rocks/ice on Europa...

That requires very difficult circumstances that almost certainly can't occur at the planetary scale.

Hmm. I did not think that the temperature of Europa's oceans (below their probable icy crust) has been well-constrained. To the extent that it has, I think the subsurface temperature is expected to be much greater than -50C in many places (the mechanism is tidal heating).

There is a general belief that Europa is likely to have significant liquid water below its icy surface. The phase diagram for water (first image at http://www1.lsbu.ac.uk/water/phase.html) does not allow liquid water at -50C = 223K, no matter what the pressure.

Atmospheric pressure on Earth is about 0.1 MPa, and gravity on Europa is about 1/6 of Earth. The highest pressure in Earth's oceans is about 1000x atmospheric pressure (100 MPa). Across this range (3 orders of magnitude), the melting point of H2O is pretty constant, 0C or a little below (see the linked phase diagram).

My conclusion: liquid water implies temperatures of at least 0C in the relevant pressure range.

Not really. https://www.youtube.com/watch?v=Fot3m7kyLn4

Also. http://en.wikipedia.org/wiki/Supercooling

From your link: A liquid below its standard freezing point will crystallize in the presence of a seed crystal or nucleus around which a crystal structure can form creating a solid.

Europa's ocean is surrounded by a vast sheet of actual ice. You can't keep such an ocean at supercooled state.

It's not likely that an entire large planetary body will maintain a state out of equilibrium for geological periods of time. Supercooling is unstable.

So, I'm assuming you don't have any basis for your assertion above? Because this is nothing to do with Europa.

Pure liquid water does indeed freeze at 0C, but the water in Europa's oceans is unlikely to be pure. The presence of salts can significantly depress the freezing point of water; ocean water on Earth freezes at about -2C or so. With just sodium chloride alone, it's possible to knock that down to about -20C. Europa's oceans are known to contain magnesium chloride (http://www.jpl.nasa.gov/news/news.php?release=2013-082), and probably have other chlorides as well. It's definitely possible, indeed likely, that the temperatures involved are sub-zero, but I agree that -50C sounds unlikely. I'm not sure what the actual lower bound would be though, given the largely unknown chemistry of the water.

Upon further research, where are you getting this number from?

http://www.lpi.usra.edu/meetings/lpsc2002/pdf/1824.pdf

Thanks for turning up some real info. The paper you found is speculative, but the options they consider all have a temperature range within a few degrees of zero C.

They entertain some scenarios whereby stratification could allow the deep temperature to get as high as ~4C without breaching the icy surface.

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