Hubble Discovers Water Plumes Erupting from Europa

UV observations from Hubble show the size of water vapor plumes coming from Europa's south pole (NASA, ESA, and M. Kornmesser)

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 (after 23 years still going strong) 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.

(Psst, NASA… hint hint.)

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 125-mile (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. (Source)

Rendering showing the location and size of water vapor plumes coming from Europa's south pole.
Rendering showing the location and size of water vapor plumes coming from Europa’s south pole.

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.

Read more: Europa’s Hidden Great Lakes May Harbor Life

“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 water vapor could be surface ice, heated through friction.

Cassini image of ice geysers on Enceladus (NASA/JPL/SSI)
Cassini image of ice geysers on Enceladus (NASA/JPL/SSI)

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

Read more: Hydrogen Peroxide Could Feed Life on Europa

So. Who’s up for a mission to Europa now? (And unfortunately in this case, Juno doesn’t count.)

“Juno is a spinning spacecraft that will fly close to Jupiter, and won’t be studying Europa,” Kurt Retherford told Universe Today. “The team is looking hard how we can optimize, maybe looking for gases coming off Europa and look at how the plasma interacts with environment, so we really need a dedicated Europa mission.”

We couldn’t agree more.

The findings were published in the Dec. 12 online issue of Science Express.

Sources: Hubble news releases (US and ESA)

Image credits:
Graphic Credit: NASA, ESA, and L. Roth (Southwest Research Institute and University of Cologne, Germany)
Science Credit: NASA, ESA, L. Roth (Southwest Research Institute and University of Cologne, Germany), J. Saur (University of Cologne, Germany), K. Retherford (Southwest Research Institute), D. Strobel and P. Feldman (Johns Hopkins University), M. McGrath (Marshall Space Flight Center), and F. Nimmo (University of California, Santa Cruz)

Where Should We Look for Life in the Solar System?

Where Should We Look for Life in the Solar System?

Emily Lakdawalla is the senior editor and planetary evangelist for the Planetary Society. She’s also one of the most knowledgeable people I know about everything that’s going on in the Solar System. From Curiosity’s exploration of Mars to the search for life in the icy outer reaches of the Solar System, Emily can give you the inside scoop.

In this short interview, Emily describes where she thinks we should be looking for life in the Solar System.

Follow Emily’s blog at the Planetary Society here.
Follow her on Twitter at @elakdawalla
And Circle her on Google+
Continue reading “Where Should We Look for Life in the Solar System?”

These Antarctic Research Photos Look Like Exploration on Another Planet

Researchers work in the Antarctic polar night during a storm (Credit: Stefan Hendricks, Alfred Wegner Institute)

Some day, human explorers will land a spacecraft on the surface of Europa, Enceladus, Titan, or some other icy world and investigate first-hand the secrets hidden beneath its frozen surface. When that day comes — and it can’t come too soon for me! — it may look a lot like this.

One of a series of amazing photos by Stefan Hendricks taken during the Antarctic Winter Ecosystem & Climate Study (AWECS), a study of Antarctica’s sea ice conducted by the Alfred Wegener Institute in Germany, the image above shows researchers working on the Antarctic ice during a winter snowstorm. It’s easy to imagine them on the night-side surface of Europa, with the research vessel Polarstern standing in for a distant illuminated lander (albeit rather oversized).

Hey, one can dream!

One of the goals of the campaign, called CryoVex, was to look at how ESA’s CryoSat mission can be used to understand the thickness of sea ice in Antarctica. The extent of the Antarctic sea ice in winter is currently more than normal, which could be linked to changing atmospheric patterns.

Antarctica’s massive shelves of sea ice in winter are quite dramatic landscapes, and remind us that there are very alien places right here on our own planet.

See this and more photos from the mission on the ESA website (really, go check them out!)

Observing Alert: Rare Triple Transit Of Jupiter’s Moons Happens Friday Night (Oct. 11-12)

Jupiter with polka dot shadows cast by Io, Europa and Callisto as depicted around 1 a.m. EDT Oct. 12. Watch for the Great Red Spot to come into view during the transit. Created with Claude Duplessis' Meridian software

Talk about a great fall lineup. Three of Jupiter’s four brightest moons plan a rare show for telescopic observers on Friday night – Saturday morning Oct. 11-12. For a span of just over an hour, Io, Europa and Callisto will simultaneously cast shadows on the planet’s cloud tops, an event that hasn’t happened since March 28, 2004.

Who doesn’t remember their first time looking at Jupiter and his entourage of dancing moons in a telescope? Because each moves at a different rate depending on its distance from the planet, they’re constantly on the move like kids in a game of musical chairs. Every night offers a different arrangement.

Jupiter and its four brightest moons seen in a small telescope. Credit: Bob King
Jupiter and its four brightest moons seen in a small telescope. Credit: Bob King

Some nights all four of the brightest are strung out on one side of the planet, other nights only two or three are visible, the others hidden behind Jupiter’s “plus-sized” globe. Occasionally you’ll be lucky enough to catch the shadow of one of moons as it transits or crosses in front of the planet. We call the event a shadow transit, but to someone watching from Jupiter, the moon glides in front of the sun to create a total solar eclipse.

Since the sun is only 1/5 as large from Jupiter as seen from Earth, all four moons are large enough to completely cover the sun and cast inky shadows. To the eye they look like tiny black dots of varying sizes. Europa, the smallest, mimics a pinprick. The shadows of Io and Callisto are more substantial. Ganymede, the solar system’s largest moon at 3,269 miles (5,262 km), looks positively plump compared to the others. Even a small telescope magnifying around 50x will show it.

Jupiter on Sept. 24 with its moon Europa (at left) casting a pinhead black shadow on Jupiter's clouds. Credit: John Chumack
Jupiter on Sept. 24 with its moon Europa (at left) casting a pinhead black shadow on Jupiter’s clouds. Credit: John Chumack

The three inner satellites – Io, Europa and Ganymede – have shadow transits every orbit. Distant Callisto only transits when Jupiter’s tilt relative to Earth is very small, i.e. the plane of the planet’s moons is nearly edge-on from our perspective. Callisto transits occur in alternating “seasons” lasting about 3 years apiece. Three years of shadow play are followed by three years of shadowless misses. Single transits are fairly common; you can find tables of them online like this one from Project Pluto or plug in time and date into a free program like Meridian for a picture and list of times.

Because Io, Europa and Ganymede orbit in a 4:2:1 resonance (Io revolves four times around Jupiter in the time it takes Ganymede to orbit once; Europa completes two orbits for Ganymede's one) a "quadruple transit" is impossible. Credit: Matma Rex / Wikipedia
Because Io, Europa and Ganymede orbit in a 4:2:1 resonance (Io revolves four times around Jupiter in the time it takes Ganymede to orbit once; Europa completes two orbits for Ganymede’s one) it’s impossible for all three to line up – along with Callsto – for a “quadruple transit”. Credit: Matma Rex / Wikipedia

Seeing two shadows inch across Jupiter’s face is very uncommon, and three are as rare as a good hair day for Donald Trump. Averaged out, triple transits occur once or twice a decade. Friday night Oct. 11 each moon enters like actors in a play. Callisto appears first at 11:12 p.m. EDT followed by Europa and then Io. By 12:32 a.m. all three are in place.

Catch them while you can. Groups like these don’t last long. A little more than an hour later Callisto departs, leaving just two shadows.  You’ll find the details below. All times are Eastern Daylight or EDT. Subtract one hour for Central time and add four hours for BST (British Summer Time):

* Callisto’s shadow enters the disk – 11:12 p.m. Oct. 11
* Europa – 11:24 p.m.
* Io – 12:32 a.m.
** TRIPLE TRANSIT from 12:32 – 1:37 a.m.
* Callisto departs – 1:37 a.m.
* Europa departs – 2:01 a.m.
* Io departs – 2:44 a.m.

Looking at Jupiter from high above the plane of the solar system, we can picture better how shadow transits and eclipses happen. Credit: Garrett Serviss from "Pleasures of the Telescope" (annotations: Bob King)
Looking at Jupiter from high above the plane of the solar system in this diagram from more than a century ago, we can better picture how shadow transits and eclipses happen. The tiny disk of Io and the shadow of Ganymede are seen in transit; Callisto is about to be eclipsed by Jupiter’s shadow.  Credit: Garrett Serviss from “Pleasures of the Telescope” (annotations: Bob King)

The triple transit will be seen across the eastern half of the U.S., Europe and western Africa. Those living on the East Coast have the best view in the U.S. with Jupiter some 20-25 degrees high in the northeastern sky around 1 a.m. local time. Things get dicier in the Midwest where Jupiter climbs to only 5-10 degrees. From the mountain states the planet won’t  rise until Callisto’s shadow has left the disk, leaving a two-shadow consolation prize. If you live in the Pacific time zone and points farther west, you’ll unfortunately miss the event altogether.

From the Eastern Time Zone Jupiter will be well-placed in the eastern sky around the time of mid-transit. Created with Stellarium
From the Eastern Time Zone Jupiter will be well-placed in the eastern sky during the transit. Created with Stellarium

Key to seeing all three shadows clearly, especially if Jupiter is low in the sky, is steady air or what skywatchers call “good seeing”. The sky can be so clear you’d swear there’s a million stars up there, but a look through the telescope will sometimes show dancing, blurry images due to invisible air turbulence. That’s “bad seeing”. Unfortunately, bad seeing is more common near the horizon where we peer through a greater thickness of atmosphere. But don’t let that keep you inside Friday night. With a spell of steady air, all you need is a 4-inch or larger telescope magnifying around 100x to spot all three.

The March 28, 2004 triple transit. Shadows from left: Ganymede, Io and Callisto. You can also see the disks of Io (white dot) and Ganymede (blue dot) in this photo taken in infrared light by the Hubble Space Telescope. Credit: NASA/ESA
The March 28, 2004 triple transit. Shadows from left: Ganymede, Io and Callisto. You can also see the disks of Io (white dot) and Ganymede (blue dot) in this photo taken in infrared light by the Hubble Space Telescope. Credit: NASA/ESA

If bad weather blocks the view, there are two more triple transits coming up soon – a 95-minute-long event on June 3, 2014 starring Europa, Ganymede and Callisto (not visible in the Americas) and a 25-minute show on Jan. 24, 2015 featuring Io, Europa and Callisto and visible across Western Europe and the Americas. That’s it until dual triple transits in 2032.

 

Hydrogen Peroxide Could Feed Life on Europa

Reprocessed Galileo image of Europa's frozen surface by Ted Stryk (NASA/JPL/Ted Stryk)
Reprocessed Galileo image of Europa's frozen surface by Ted Stryk (NASA/JPL/Ted Stryk)

According to research by NASA astronomers using the next-generation optics of the 10-meter Keck II telescope, Jupiter’s ice-encrusted moon Europa has hydrogen peroxide across much of the surface of its leading hemisphere, a compound that could potentially provide energy for life if it has found its way into the moon’s subsurface ocean.

“Europa has the liquid water and elements, and we think that compounds like peroxide might be an important part of the energy requirement,” said JPL scientist Kevin Hand, the paper’s lead author. “The availability of oxidants like peroxide on Earth was a critical part of the rise of complex, multicellular life.”

The paper, co-authored by Mike Brown of the California Institute of Technology in Pasadena, analyzed data in the near-infrared range of light from Europa using the Keck II Telescope on Mauna Kea, Hawaii, over four nights in September 2011. The highest concentration of peroxide found was on the side of Europa that always leads in its orbit around Jupiter, with a peroxide abundance of 0.12 percent relative to water. (For perspective, this is roughly 20 times more diluted than the hydrogen peroxide mixture available at drug stores.) The concentration of peroxide in Europa’s ice then drops off to nearly zero on the hemisphere of Europa that faces backward in its orbit.

Hydrogen peroxide was first detected on Europa by NASA’s Galileo mission, which explored the Jupiter system from 1995 to 2003, but Galileo observations were of a limited region. The new Keck data show that peroxide is widespread across much of the surface of Europa, and the highest concentrations are reached in regions where Europa’s ice is nearly pure water with very little sulfur contamination.

This color composite view combines violet, green, and infrared images of Europa acquired by Galileo in 1997 for a view of the moon in natural color (left) and in enhanced color (right). Credit: NASA/JPL/University of Arizona
This color composite view combines violet, green, and infrared images of Europa acquired by Galileo in 1997 for a view of the moon in natural color (left) and in enhanced color (right). Credit: NASA/JPL/University of Arizona

The peroxide is created by the intense radiation processing of Europa’s surface ice that comes from the moon’s location within Jupiter’s strong magnetic field.

“The Galileo measurements gave us tantalizing hints of what might be happening all over the surface of Europa, and we’ve now been able to quantify that with our Keck telescope observations,” Brown said. “What we still don’t know is how the surface and the ocean mix, which would provide a mechanism for any life to use the peroxide.”

Read more: Evidence for a Deep Ocean on Europa Might Be Found on its Surface

The scientists think hydrogen peroxide is an important factor for the habitability of the global liquid water ocean under Europa’s icy crust because hydrogen peroxide decays to oxygen when mixed into liquid water. “At Europa, abundant compounds like peroxide could help to satisfy the chemical energy requirement needed for life within the ocean, if the peroxide is mixed into the ocean,” said Hand.

(Source: NASA)

What’s notable to add, on March 26, 2013, the U.S. President signed a bill that would increase the budget for NASA’s planetary science program as well as provide $75 million for the exploration of Europa. Exactly how the funds will be used isn’t clear — perhaps for components on the proposed Europa Clipper mission? —  but it’s a step in the right direction for learning more about this increasingly intriguing world. Read more on SETI’s Destination: Europa blog.

Evidence for a Deep Ocean on Europa Might be Found on its Surface

Astronomers hypothesize that chloride salts bubble up from the icy moon's global liquid ocean and reach the frozen surface where they are bombarded with sulfur from volcanoes on Jupiter's largest moon, Io. This illustration of Europa (foreground), Jupiter (right) and Io (middle) is an artist's concept. Credit: Keck Observatory.

Astronomer Mike Brown and his colleague Kevin Hand might be suffering from “Pump Handle Phobia,” as radio personality Garrison Keillor calls it, where those afflicted just can’t resist putting their tongues on something frozen to see if it will stick. But Brown and Hand are doing it all in the name of science, and they may have found the best evidence yet that Europa has a liquid water ocean beneath its icy surface. Better yet, that vast subsurface ocean may actually shoot up to Europa’s surface, on occasion.

In a recent blog post, Brown pondered what it would taste like if he could lick the icy surface of Jupiter’s moon Europa. “The answer may be that it would taste a lot like that last mouthful of water that you accidentally drank when you were swimming at the beach on your last vacation. Just don’t take too long of a taste. At nearly 300 degrees (F) below zero your tongue will stick fast.”

His ponderings were based on a new paper by Brown and Hand which combined data from the Galileo mission (1989 to 2003) to study Jupiter and its moons, along with new spectroscopy data from the 10-meter Keck II telescope in Hawaii.

The study suggests there is a chemical exchange between the ocean and surface, making the ocean a richer chemical environment.

“We now have evidence that Europa’s ocean is not isolated—that the ocean and the surface talk to each other and exchange chemicals,” said Brown, who is an astronomer and professor of planetary astronomy at Caltech. “That means that energy might be going into the ocean, which is important in terms of the possibilities for life there. It also means that if you’d like to know what’s in the ocean, you can just go to the surface and scrape some off.”

“The surface ice is providing us a window into that potentially habitable ocean below,” said Hand, deputy chief scientist for solar system exploration at JPL.

Europa’s ocean is thought to cover the moon’s whole globe and is about 100 kilometers (60 miles) thick under a thin ice shell. Since the days of NASA’s Voyager and Galileo missions, scientists have debated the composition of Europa’s surface.

Salts were detected in the Galileo data – “Not ‘salt’ as in the sodium chloride of your table salt,” Brown wrote in his blog, “Mike Brown’s Planets,” “but more generically ‘salts’ as in ‘things that dissolve in water and stick around when the water evaporates.’”

That idea was enticing, Brown said, because if the surface is covered by things that dissolve in water, that strongly implies that Europa’s ocean water has flowed on the surface, evaporated, and left behind salts.

But there were other explanations for the Galileo data, as Europa is constantly bombarded by sulfur from the volcanoes on Io, and the spectrograph that was on the Galileo spacecraft wasn’t able to tell the difference between salts and sulfuric acid.

But now, with data from the Keck Observatory, Brown and Hand have identified a spectroscopic feature on Europa’s surface that indicates the presence of a magnesium sulfate salt, a mineral called epsomite, that could have formed by oxidation of a mineral likely originating from the ocean below.

This view of Jupiter's moon Europa features several regional-resolution mosaics overlaid on a lower resolution global view for context. The regional views were obtained during several different flybys of the moon by NASA's Galileo mission.  Image credit: NASA/JPL-Caltech/University of Arizona.
This view of Jupiter’s moon Europa features several regional-resolution mosaics overlaid on a lower resolution global view for context. The regional views were obtained during several different flybys of the moon by NASA’s Galileo mission. Image credit: NASA/JPL-Caltech/University of Arizona.

Brown and Hand started by mapping the distribution of pure water ice versus anything else. The spectra showed that even Europa’s leading hemisphere contains significant amounts of non-water ice. Then, at low latitudes on the trailing hemisphere — the area with the greatest concentration of the non-water ice material — they found a tiny, never-before-detected dip in the spectrum.

The two researchers tested everything from sodium chloride to Drano in Hand’s lab at JPL, where he tries to simulate the environments found on various icy worlds. At the end of the day, the signature of magnesium sulfate persisted.

The magnesium sulfate appears to be generated by the irradiation of sulfur ejected from the Jovian moon Io and, the authors deduce, magnesium chloride salt originating from Europa’s ocean. Chlorides such as sodium and potassium chlorides, which are expected to be on the Europa surface, are in general not detectable because they have no clear infrared spectral features. But magnesium sulfate is detectable. The authors believe the composition of Europa’s ocean may closely resemble the salty ocean of Earth.

While no one is going to be traveling to Europa to lick its surface, for now, astronomers will continue to use the modern giant telescopes on Earth to continue to “take spectral fingerprints of increasing detail to finally understand the mysterious details of the salty ocean beneath the ice shell of Europa,” Brown said.

Also, NASA is looking into options to explore Europa further. (Universe Today likes the idea of a big drill or submarine!)

But in the meantime what happens next? “We look for chlorine, I think,” Brown wrote. “The existence of chlorine as one of the main components of the non-water-ice surface of Europa is the strongest prediction that this hypothesis makes. We have some ideas on how we might look; we’re working on them now. Stay tuned.”

Read Brown & Hand’s paper.

Sources: Mike Brown’s Planets, Keck Observatory, JPL

In an Isolated, Ice-Covered Antarctic Lake Far Below Freezing, Life is Found

Lake Vida lies within one of Antarctica’s cold, arid McMurdo Dry Valleys (Photo: Desert Research Institute)

Even inside an almost completely frozen lake within Antarctica’s inland dry valleys, in dark, salt-laden and sub-freezing water full of nitrous oxide, life thrives… offering a clue at what might one day be found in similar environments elsewhere in the Solar System.


Researchers from NASA, the Desert Research Institute in Nevada, the University of Illinois at Chicago and nine other institutions have discovered colonies of bacteria living in one of the most isolated places on Earth: Antarctica’s Lake Vida, located in Victoria Valley — one of the southern continent’s incredibly arid McMurdo Dry Valleys.

These organisms seem to be thriving despite the harsh conditions. Covered by 20 meters (65 feet) of ice, the water in  Lake Vida is six times saltier than seawater and contains the highest levels of nitrous oxide ever found in a natural body of water. Sunlight doesn’t penetrate very far below the frozen surface, and due to the hypersaline conditions and pressure of the ice water temperatures can plunge to a frigid -13.5 ºC (8 ºF).

Yet even within such a seemingly inhospitable environment Lake Vida is host to a “surprisingly diverse and abundant assemblage of bacteria” existing within water channels branching through the ice, separated from the sun’s energy and isolated from exterior influences for an estimated 3,000 years.

Originally thought to be frozen solid, ground penetrating radar surveys in 1995 revealed a very salty liquid layer (a brine) underlying the lake’s year-round 20-meter-thick ice cover.

“This study provides a window into one of the most unique ecosystems on Earth,” said Dr. Alison Murray, one of the lead authors of the team’s paper, a molecular microbial ecologist and polar researcher and a member of 14 expeditions to the Southern Ocean and Antarctic continent. “Our knowledge of geochemical and microbial processes in lightless icy environments, especially at subzero temperatures, has been mostly unknown up until now. This work expands our understanding of the types of life that can survive in these isolated, cryoecosystems and how different strategies may be used to exist in such challenging environments.”

Sterile environments had to be set up within tents on Lake Vida’s surface so the researchers could be sure that the core samples they were drilling were pristine, and weren’t being contaminated with any introduced organisms.

According to a NASA press release, “geochemical analyses suggest chemical reactions between the brine and the underlying iron-rich sediments generate nitrous oxide and molecular hydrogen. The latter, in part, may provide the energy needed to support the brine’s diverse microbial life.”

“This system is probably the best analog we have for possible ecosystems in the subsurface waters of Saturn’s moon Enceladus and Jupiter’s moon Europa.”

– Chris McKay, co-author, NASA’s Ames Research Center

What’s particularly exciting is the similarity between conditions found in ice-covered Antarctic lakes and those that could be found on other worlds in our Solar System. If life could survive in Lake Vida, as harsh and isolated as it is, could it also be found beneath the icy surface of Europa, or within the (hypothesized) subsurface oceans of Enceladus? And what about the ice caps of Mars? Might there be similar channels of super-salty liquid water running through Mars’ ice, with microbes eking out an existence on iron sediments?

“It’s plausible that a life-supporting energy source exists solely from the chemical reaction between anoxic salt water and the rock,” explained Dr. Christian Fritsen, a systems microbial ecologist and Research Professor in DRI’s Division of Earth and Ecosystem Sciences and co-author of the study.

“If that’s the case,” Murray added, “this gives us an entirely new framework for thinking of how life can be supported in cryoecosystems on earth and in other icy worlds of the universe.”

Read more: Europa’s Hidden Great Lakes May Harbor Life

More research is planned to study the chemical interactions between the sediment and the brine as well as the genetic makeup of the microbial communities themselves.

The research was published this week in the Proceedings of the National Academy of Science (PNAS). Read more on the DRI press release here, and watch a video below showing highlights from the field research.

Funding for the research was supported jointly by NSF and NASA. Images courtesy the Desert Research Institute. Dry valley image credit: NASA/Landsat. Europa image: NASA/Ted Stryk.)

Enticing Trailer for New Movie about a Mission to Europa

Here’s a trailer from a new movie called “Europa Report” about a near-future mission to Jupiter’s moon, Europa, in search of extraterrestrial life. From the trailer, the film looks to be of extremely high quality, and it stars Sharlto Copley (District 9), with music score from composer Bear McCreary (Battlestar Galactica).

And while this is a sci-fi flick, the makers of “Europa Report” say they are trying to steep it in real science.

The PR for the film is just getting underway, but they have a realistic-looking website that appears to show webcam views from a spacecraft heading to Europa.

Screenshot:

Here’s the blurb from the website:

For decades, scientists have theorized the existence of liquid water oceans on Jupiter’s moon, Europa. We’ve recently discovered new, captivating evidence that these sub-surface oceans do exist and could support life.

We’ve sent six astronauts from space programs throughout the world on a three year journey to Europa to explore its oceans and confirm these findings.

We’re proud to be at the forefront of the effort to prove the existence of extra-terrestrial life within our solar system, within our lifetimes.

And yep, like any film about spaceflight, something has to go wrong during the mission.

The release date for the film has not yet been set.

ESA Turns On The JUICE For New Jupiter Mission

Galileo image of Ganymede, Jupiter's - and the Solar System's - largest moon. (Ted Stryk)

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The European Space Agency has given the go-ahead for an exciting mission to explore the icy moons of Jupiter, as well as the giant planet itself.

JUICEJUpiter ICy moons Explorer — will consist of a solar-powered spacecraft that will spend 3.5 years within the Jovian system, investigating Ganymede, Europa and the upper atmosphere of Jupiter. Anticipated to launch in June 2022, JUICE would arrive at Jupiter in early 2030.

As its name implies, JUICE’s main targets are Jupiter’s largest icy moons — Ganymede and Europa — which are thought to have liquid oceans concealed beneath their frozen surfaces.

The largest moon in the Solar System, Ganymede is also thought to have a molten iron core generating a magnetic field much like Earth’s. The internal heat from this core may help keep Ganymede’s underground ocean liquid, but the dynamics of how it all works are not quite understood.

JUICE will also study the ice-coated Europa, whose cueball-smooth surface lined with cracks and jumbled mounds of frozen material seem to be sure indicators of a subsurface ocean, although how deep and how extensive is might be are still unknown — not to mention its composition and whether or not it could be hospitable to life.

The rust-colored cracks lining Europa's otherwise smooth surface hint at a subsurface ocean. (Ted Stryk)

“JUICE will give us better insight into how gas giants and their orbiting worlds form, and their potential for hosting life,” said Professor Alvaro Giménez Cañete, ESA’s Director of Science and Robotic Exploration.

The JUICE spacecraft was originally supposed to join a NASA mission dedicated to the investigation of Europa, but NASA deemed their proposed mission too costly and it was cancelled. According to Robert Pappalardo, study scientist for the Europa mission based at JPL, NASA may still supply some instruments for the spacecraft “assuming that the funding situation in the United States can bear it.”

Artist's rendering of JUICE at Jupiter. (ESA/AOES)

JUICE will also capture images of Jupiter’s moon Callisto and search for aurorae in the gas giant’s upper atmosphere, as well as measure the planet’s powerful magnetic field. Once arriving in 2030, it will spend at least three years exploring the Jovian worlds.

Read more in today’s news release from Nature, and stay tuned to ESA’s JUICE mission page here.

Recalibrated Galileo images © Ted Stryk. See more of Ted’s excellent work on his site Planetary Images From Then And Now.

Europa’s Acidic Oceans May Prohibit Life

Europa's bizarre surface features suggest an actively churning ice shell above a salty liquid water ocean. That liquid could carry amino acids and signs of life to the surface. Credit: JPL
Europa's bizarre surface features suggest an actively churning ice shell above a salty liquid water ocean. That liquid could carry amino acids and signs of life to the surface. Credit: JPL

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The more we explore our solar system, the more we find things in common. Jupiter’s frigid moon – Europa – is about the size of our satellite and – like Earth – home to some very hostile environments. Underneath what is surmised to be an icy crust a few miles deep, Europa may possess an acidic ocean that could extend down as much as 100 miles (160 km) below the surface. We know from exploring our home planet that life happens under some very extreme conditions here… But what about Europa? What are the chances that life could exist there, too?

Check out liquid water on Earth and you’ll find some form of life. As a given, scientists hypothesize other worlds which contain water should also support life. According to recent studies, Europa’s ocean might even be saturated with oxygen – further supporting these theories. However, there’s a catch. Like Earth, surface chemicals are continually drawn downward. According to researcher Matthew Pasek, an astrobiologist at the University of South Florida, this could constitute a highly acidic ocean which “is probably not friendly to life — it ends up messing with things like membrane development, and it could be hard building the large-scale organic polymers.”

According to Charles Choi of Astrobiology Magazine, “The compounds in question are oxidants, which are capable of receiving electrons from other compounds. These are usually rare in the solar system because of the abundance of chemicals known as reductants such as hydrogen and carbon, which react quickly with oxidants to form oxides such as water and carbon dioxide. Europa happens to be rich in strong oxidants such as oxygen and hydrogen peroxide which are created by the irradiation of its icy crust by high-energy particles from Jupiter.”

Although it’s speculation, if Europa produces oxidants, they may also be drawn toward its core from ocean motion. However, it might be infused with sulfides and other compounds creating sulfuric and other acids before supporting life. According to the researchers, if this has happened for just half of Europa’s lifetime, the result would be corrosive, with a pH of about 2.6, “about the same as your average soft drink,” Pasek said. While this wouldn’t prohibit life from forming, it wouldn’t make it easy. Emerging life forms would have to be quick to consume oxidants and build an acid tolerance – a process which could take as much as 50 million years.

Are there similar acid-lovin’ lifeforms on Earth? You bet. They exist in acid mine drainage found in Spain’s Rio Tinto river and they feed on iron and sulfide for their metabolic energy. “The microbes there have figured out ways of fighting their acidic environment,” Pasek said. “If life did that on Europa, Ganymede, and maybe even Mars, that might have been quite advantageous.” It is also possible that sediments at the bottom of Europa’s ocean may neutralize the acids, even though Pasek speculates this isn’t likely. One thing we do know about an acidic ocean is that it dissolves calcium-based materials such as bones and shells.

It’s a lesson repeated on Earth…

Right now our oceans are absorbing excess carbon dioxide from the air which – when combined with seawater – forms carbonic acid. While it is mostly neutralized by fossil carbonate shells at the ocean’s bed, if it’s absorbed too quickly it can have some major ramifications on sea life such as coral reefs, plankton and mollusks. According to a recent study, this acidification is happening faster (thanks to human carbon emissions) than it has during four major extinction events on Earth in the last 300 million years.

“What we’re doing today really stands out,” said lead author Bärbel Hönisch, a paleoceanographer at Columbia University’s Lamont-Doherty Earth Observatory. “We know that life during past ocean acidification events was not wiped out—new species evolved to replace those that died off. But if industrial carbon emissions continue at the current pace, we may lose organisms we care about—coral reefs, oysters, salmon.”

According to this new research, our carbon dioxide levels have escalated by 30% in the last century. This means we’ve jumped to to 393 parts per million, and ocean pH has fallen by 0.1 unit, to 8.1–an acidification rate at least 10 times faster than 56 million years ago, says Hönisch. If this continues, the Intergovernmental Panel on Climate Change predicts the pH may drop as much as another 0.3 units… a drop that will constitute major biologic changes. While you might scoff at the extinction of a few forms of plankton or the annihilation of a small coral or shellfish, there is a ripple effect that cannot be denied.

“It’s not a problem that can be quickly reversed,” said Christopher Langdon, a biological oceanographer at the University of Miami who co-authored the study on Papua New Guinea reefs. “Once a species goes extinct it’s gone forever. We’re playing a very dangerous game.”

It may take decades before ocean acidification’s effect on marine life shows itself. Until then, the past is a good way to foresee the future, says Richard Feely, an oceanographer at the National Oceanic and Atmospheric Administration who was not involved in the study. “These studies give you a sense of the timing involved in past ocean acidification events—they did not happen quickly,” he said. “The decisions we make over the next few decades could have significant implications on a geologic timescale.”

For now, we’ll look to Europa and wonder at what may exist below its frozen waves. Is there an acid-loving form of life just waiting to bubble to the surface for us to find? Right now researchers are developing a drill which could assist in looking for extreme forms of life. The “penetrator” could eventually be part of a Europa exploration mission which could begin as early as 2020.

“Penetrators are the most feasible, cheapest and safest option for a landing on Europa today, and the knowledge to build those is there,” said Peter Weiss, a post-doc now at the National Center for Scientific Research (CNRS) in France. “Otherwise, we won’t have any confirmation on astrobiology on Europa — or maybe even in the solar system — during our lifetime.”

Original Story Source: Astrobiology Magazine. For Further Reading: Physorg.com.