Water Plumes Erupting from Europa’s south pole!

[neufer]

Hubble Discovers Water Plumes Erupting from Europa
by Jason Major on December 12, 2013

[b][color=#0000FF][size=150]UV observations from Hubble show the size of water vapor plumes coming from Europa’s south pole[/size][/color][/b]

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<<It’s been known since 2005 that Saturn’s 300-mile-wide moon Enceladus has geysers spewing ice and dust out into orbit from deep troughs that rake across its south pole. Now, thanks to the Hubble Space Telescope, we know of another moon with similar jets: Europa, the ever-enigmatic ice-shelled moon of Jupiter. This makes two places in our Solar System where subsurface oceans could be getting sprayed directly into space — and within easy reach of any passing spacecraft.

The findings were announced today during the meeting of the American Geophysical Union in San Francisco. “The discovery that water vapor is ejected near the south pole strengthens Europa’s position as the top candidate for potential habitability,” said lead author Lorenz Roth of the Southwest Research Institute (SwRI) in San Antonio, Texas. ”However, we do not know yet if these plumes are connected to subsurface liquid water or not.”

The 200-km -high plumes were discovered with Hubble observations made in December 2012. Hubble’s Space Telescope Imaging Spectrograph (STIS) detected faint ultraviolet light from an aurora at the Europa’s south pole. Europa’s aurora is created as it plows through Jupiter’s intense magnetic field, which causes particles to reach such high speeds that they can split the water molecules in the plume when they hit them. The resulting oxygen and hydrogen ions revealed themselves to Hubble with their specific colors.

Unlike the jets on Enceladus, which contain ice and dust particles, only water has so far been identified in Europa’s plumes.

The team suspects that the source of the water is Europa’s long-hypothesized subsurface ocean, which could contain even more water than is found across the entire surface of our planet. “If those plumes are connected with the subsurface water ocean we are confident exists under Europa’s crust, then this means that future investigations can directly investigate the chemical makeup of Europa’s potentially habitable environment without drilling through layers of ice,” Roth said. “And that is tremendously exciting.” One other possible source of the plumes could be surface ice, heated through friction.

In addition the Hubble team found that the intensity of Europa’s plumes, like those of Enceladus, varies with the moon’s orbital position around Jupiter. Active jets have been seen only when Europa is farthest from Jupiter. But the researchers could not detect any sign of venting when Europa is closer. One explanation for the variability is Europa undergoes more tidal flexing as gravitational forces push and pull on the moon, opening vents at larger distances from Jupiter. The vents get narrowed or even seal off entirely when the moon is closest to Jupiter.

Still, the observation of these plumes — as well as their varying intensity — only serves to further support the existence of Europa’s ocean. “The apparent plume variability supports a key prediction that Europa should tidally flex by a significant amount if it has a subsurface ocean,” said Kurt Retherford, also of SwRI. (Science buzzkill alert: although exciting, further observations will be needed to confirm these findings. “This is a 4 sigma detection, so a small uncertainly that the signal is just noise in the instruments,” noted Roth.) “If confirmed, this new observation once again shows the power of the Hubble Space Telescope to explore and opens a new chapter in our search for potentially habitable environments in our solar system.” – John Grunsfeld, NASA’s Associate Administrator for Science>>

. http://www.planetary.org/blogs/guest-bl ... uropa.html

[geckzilla]

I saw the images released with this earlier today. They are definitely some of the more confusing ones I've seen. I would have liked to also see the tiny but real image data which I assume those blue pixels came from.

[Chris Peterson]

I saw the images released with this earlier today. They are definitely some of the more confusing ones I've seen. I would have liked to also see the tiny but real image data which I assume those blue pixels came from.

Try the paper that describes this work.

[geckzilla]

Thanks, I had just finished looking at that and was about to make this post. Here are actual pictures of the plumes from that paper. About what I expected. I'm still not sure if it's better to show these sorts of things or create artists' impressions for them.

Fig. 1: Visible images of the observed hemispheres (A-C) with sub-observer longitudes listed and combined STIS images of the hydrogen and oxygen emissions (D-O) (Table 1). The Lyman- α morphology (D-F) reveals an anti-correlation with the brightness in the visible (15). (G-O): Same Lyman-α images, and OI130.4 nm and OI]135.6 nm images with solar disk-reflectance subtracted. 3×3 pixels are binned and the STIS images are smoothed to enhance visibility of the significant features. The dotted light blue circles indicate the multiplet lines (15). The color scale is normalized to the respective brightness and the scale maximum (corresponding to 1.0 on the scale) is listed in each image. Oversaturated pixels with intensities above maximum are white. The contours show signal-to-noise (SNR) ratios of the binned pixels (and contours for SNR=1 are omitted here in (D-F) and (M-O)).

...

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[neufer]

A Europa plume sample return mission would require only about 45% of the travel time
of an Enceladus' plume sample mission and would be able to use solar panels instead of RTGs.

Saturn Moon Enceladus Eyed for Sample-Return Mission
by Mike Wall, SPACE.com Senior Writer, December 06, 2012

SAN FRANCISCO —<< Scientists are developing a mission concept that would snag icy particles from Saturn's moon Enceladus and return them to Earth, where they could be analyzed for signs of life. The spacecraft would fly through the icy plume blasted into space by geysers near Enceladus' south pole, then send the collected particles back to our planet in a return capsule. Enceladus may be capable of supporting life, and the flyby sample-return mission would bring pieces from its depths to Earth at a reasonable price, researchers said. "This is really the low-hanging fruit" of sample-return missions, said study leader Peter Tsou of Sample Exploration Systems in La Canada, Calif., who presented the idea here Wednesday (Dec. 5) at the annual fall meeting of the American Geophysical Union. "It would be a shame not to pick it."

Life as we know it requires four things, Tsou said: liquid water, carbon, nitrogen and an energy source. All four are present at Enceladus, and as a result many researchers regard it as one of the solar system's best bets to host life as we know it. Enceladus is the sixth-largest moon of Saturn, with a diameter of 505 kilometers. Scientists believe a large ocean of liquid water sloshes beneath the moon's icy shell. Enceladus generates huge amounts of heat internally, with much of it perhaps being produced by tidal interactions with Dione, another Saturn satellite. This heat powers the geysers from Enceladus' south pole, which eject water ice, carbon-containing organic compounds and other materials from the moon's subsurface into space.

The proposed spacecraft would enter into Saturn orbit to slow down and enable possible multiple passes by Enceladus. It would then fly through the moon's icy plume, collecting geyser particles in a cushioning aerogel. A small return capsule would deliver the samples to Earth, where scientists could search them for amino acids and other possible biomolecules. Sample-return is the preferred strategy when it comes to hunting for signs of life on other worlds, Tsou said. An automated probe in the depths of space would have a bare-bones analytical toolset, and it could perform only a limited number of experiments for a relatively short time. But here on Earth, researchers in fully equipped labs all over the world could conduct numerous experiments and potentially corroborate big discoveries claimed by other groups. "You need very precise, repeated measurements," Tsou told SPACE.com.

No big technological advances are necessary to make the mission happen, Tsou said. In fact, something similar has already been done. NASA's Stardust mission — which Tsou served as deputy principal investigator for — collected particles from Comet Wild 2 and successfully returned them to Earth in 2006. "Technology-wise, Stardust proved that this can be done," Tsou said.

Cost is a bigger issue. Initial incarnations of the Enceladus sample-return concept were estimated to cost around $1.2 billion, Tsou said — an uncomfortably large sum in these tough fiscal times. But Tsou and his colleagues have pared the potential mission down, making the spacecraft — which would be roughly 5m high and 3m wide — leaner and more focused.

As currently envisioned, the probe's science gear would consist of an aerogel collector, a tool for trapping volatile chemicals, a mass spectrometer, a navigation camera and a dust counter (so mission scientists could confirm that they'd flown through the plume).

For power, the spacecraft would rely on an advanced stirling radioisotope generator (ASRG), which converts the heat produced by radioactive decay of plutonium-238 into electricity. Tsou said that the ASRG is much more efficient at this conversion than radioisotope thermoelectric generators (RTGs), which have powered space probes for decades.

Tsou said the team wants Enceladus sample-return to fly as a NASA Discovery mission, meaning it would be capped at $425 million in 2010 dollars, not including the launch vehicle. The researchers hope to propose the mission at the next Discovery opportunity, which may come in 2015 or so, Tsou said. If the mission is approved, it could probably be ready to launch by 2020, Tsou added. Samples from Enceladus' plume would make it to Earth about 14 years later.

Enceladus is a great candidate for sample-return, Tsou said. Its geyser-blasted particles are fresh, having come right out of the moon's subsurface ocean. The mission can be done without landing on and re-launching from another world, two costly and complicating extra steps. And Enceladus seems to have all the ingredients necessary to support life. "That doesn't mean life is there," Tsou said. "But we want to find out.">>

[Ann]

This is very interesting!

There is already some signs of organic material on the surface of Europa (the reddish splotches there). Now water has been found emanating from Europa, too.

Ann

[THX1138]

Indeed and I almost live for the day we have a probe there capable of melting itself through the ice to get to that ocean underneath. .
Contrasts to China for it’s successful soft landing of their lunar rover the moon, if only there were more countries on this rock with similar space exploration programs going…………So much more science could be taking place
But…… sadly missiles, fighter jets and aircraft carriers are where most of the cash goes as usual. It really seems to me that humans ( for the most part ) are quite insane

[geckzilla]

It really seems to me that humans ( for the most part ) are quite insane

Yes, quite! (Well worth watching the entire 15 minutes)

[THX1138]

Thanks geckzilla it was well worth watching and my entire disposition has been changed in the process.
Its no longer a question or an " it seems to me " situation
There is something deeply wrong within the psyche of our species and ts down right amazing that humans have even made it this far

[Beyond]

WOW An atomic instrumental.

[bystander]

Europa's choppy ocean looks friendly to life
New Scientist | Astrophile | Nicola Guttridge | 2013 Dec 01

Object: Europa's subsurface ocean
Interesting property: Intense turbulence

[url=http://photojournal.jpl.nasa.gov/catalog/PIA03878][b][i]Europa's freckled skin[/i][/b][/url] [b][i](Credit: NASA/JPL/University of Arizona/University of Colorado)[/i][/b]

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As moons go, Europa is doing pretty well in the looks department. While other wrinkled and pockmarked planetary bodies look their age, Jupiter's moon, despite being billions of years old, is one of the smoothest objects in our solar system.

However, this moon is far from flawless. Europa is suspected to have a perpetually dark, liquid water ocean enclosed beneath a thick shell of water ice – around 40 per cent of which is covered with long, dark scratches and scars.

The prospect of liquid water places Europa near the top of the list of places in our solar system that might host alien life. However, it is hard to know what's actually going on in the sub-surface ocean. Does it teem with alien microbes – perhaps even bigger creatures – or is it a vast, inky, sterile wasteland?

The only window we have on the ocean is its icy surface, so scientists try to read its criss-cross scars for clues. But whether this so-called chaos terrain can tell us about what's going on underneath such a thick layer of ice is hotly disputed.

Oceanic chaos

The criss-cross pattern is likely to be caused by warmer and thinner regions of ice breaking and refreezing. It is much more abundant around the moon's equatorial regions than at its poles – but why should this be the case?

Unlike on Earth, the temperature difference between the equator and poles cannot be explained by the effects of the sun because its light is too faint and Europa's surface too reflective.

Another theory involves Jupiter's gravitational pull, which would produce tectonic forces and heat up Europa's ocean – but models have shown that this would heat the poles more than the equator.

The latest study suggests that turbulence in Europa's ocean sculpts the chaos terrain on the icy surface. It was previously assumed that an effect caused by the moon's rotation – known as the Coriolis force – dominates the ocean's flow, funnelling heat to high latitudes. The new model instead relies on ocean currents caused by convection of the moon's internal heat.

Mix for life

The team found that this produces a chaos terrain very similar to the one seen on Europa. "The resulting flow is less organised, but more vigorous in the equatorial region," says researcher Johannes Wicht of the Max Planck Institute for Solar System Research in Lindau, Germany. "This correlates nicely with the distribution of chaos terrain."

The model suggests that the ocean is extremely turbulent, with three strong ocean jets. So despite the thickness of Europa's icy shell, it seems that properties of its ocean are writ in the ice. "We may be able to understand Europa's ocean just by looking at the surface," says Wicht's colleague Britney Schmidt of the Georgia Institute of Technology in Atlanta.

A turbulent ocean would be beneficial for any life there because it would help shift nutrients from the sea floor into the rest of the ocean, says Schmidt's other colleague, Krista Soderlund of the University of Texas at Austin. Microbes can live in stagnant water, but knowing the ocean is turbulent makes life much more likely.

Upcoming missions such as the European Space Agency's Jupiter Icy Moons Explorer (JUICE), will map Europa's chaos terrain via fly-bys in 2030, and potentially NASA's Europa Clipper, will find out more – although it is just a concept at the moment.

Studies of Europa's chaos terrain may have relevance beyond Jupiter's moon. "Icy subsurface oceans may be commonplace in the outer solar system," says Leigh Fletcher of the University of Oxford, a member of the ESA Science Working Team for JUICE. "JUICE will also search for any active plumes and vents, just like on Saturn's moon Enceladus, to offer a glimpse into this icy ocean. This will be a great test of this sort of model for the icy worlds of our solar system."

Ocean-driven heating of Europa’s icy shell at low latitudes - K. M. Soderlund et al

• Nature Geoscience (online 01 Dec 2013 ) DOI: 10.1038/ngeo2021

Clay-Like Minerals Found on Icy Crust of Europa
NASA | JPL-Caltech | 2013 Dec 11

Hubble Sees Evidence of Water Vapor Venting off Jovian Moon
NASA | STScI | HubbleSite | 2013 Dec 12

Hubble discovers water vapour venting from Jupiter’s moon Europa
ESA/HEIC Hubble Science Release | 2013 Dec 12

Transient Water Vapor at Europa’s South Pole - Lorenz Roth et al

• Science Express (Online 12 Dec 2013) DOI: 10.1126/science.1247051 (pdf)

http://asterisk.apod.com/viewtopic.php?t=32586

<< Previous Astrophile

[Nitpicker]

The latest study suggests that turbulence in Europa's ocean sculpts the chaos terrain on the icy surface. It was previously assumed that an effect caused by the moon's rotation – known as the Coriolis force – dominates the ocean's flow, funnelling heat to high latitudes. The new model instead relies on ocean currents caused by convection of the moon's internal heat.

In both the old and the new models, the heat transfer is via convection (which is the form of heat transfer conveyed by a liquid or gas). In the old model it is forced convection and in the new model it is free convection which dominates. In both models, the flows would be turbulent (as opposed to laminar), but apparently more so in the new model.

I've always imagined there to be incredible tidal flows under the ice, too, sloshing around like mad, despite Europa being (nearly or completely) tidally locked with Jupiter.

Of course, we won't know for sure until we send some dolphins with laser beams strapped to their heads. Wait, no, they wouldn't be sterile. Back to the drawing board.