W. M. Keck Observatory: Extreme Volcanic activity on Jupiter's moon Io

These are images of Io obtained at different infrared wavelengths (in microns, μm, or millionths of a meter) with the W. M. Keck Observatory's 10-meter Keck II telescope on Aug. 15, 2013 (a-c) and the Gemini North telescope on Aug. 29, 2013 (d). 

The bar on the right of each image indicates the intensity of the infrared emission. 

Note that emissions from the large volcanic outbursts on Aug. 15 at Rarog and Heno Paterae have substantially faded by Aug. 29. 

A second bright spot is visible to the north of the Rarog and Heno eruptions in c and to the west of the outburst in d. 

This hot spot was identified as Loki Patera, a lava lake that appeared to be particularly active at the same time. 

Credit: Imke de Pater and Katherine de Kleer, UC Berkeley.

Three massive volcanic eruptions occurred on Jupiter's moon Io within a two-week period last August, leading astronomers to speculate that these presumed rare "outbursts," which can send material hundreds of miles above the surface, might be much more common than astronomers thought.

"We typically expect one huge outburst every one or two years, and they're usually not this bright," said Imke de Pater, professor and chair of astronomy at the University of California, Berkeley, and lead author of one of two papers describing the eruptions.

"Here we had three extremely bright outbursts, which suggest that if we looked more frequently we might see many more of them on Io."

Io, the innermost of Jupiter's four large "Galilean" moons, is about 2,300 miles across, about the size of Earth's moon.

Aside from Earth, is the only known place in the solar system with volcanoes erupting extremely hot lava like that seen on Earth.

Because of Io's low gravity, large volcanic eruptions produce an umbrella of debris that rises high into space.

Images of Io were taken in the near-infrared with adaptive optics at the Gemini North telescope tracking the evolution of the eruption as it decreased in intensity over 12 days. 

Due to Io's rapid rotation, a different area of the surface is viewed on each night; the outburst is visible with diminishing brightness on Aug. 29 & 30 and Sept. 1, 3, & 10. 

Credit: Katherine de Kleer/UC Berkeley/Gemini Observatory/AURA

De Pater's long-time colleague and coauthor Ashley Davies, a volcanologist with NASA's Jet Propulsion Laboratory at the California Institute of Technology in Pasadena, Calif., said that the recent eruptions match past events that spewed tens of cubic miles of lava over hundreds of square miles in a short period of time.

"These new events are in a relatively rare class of eruptions on Io because of their size and astonishingly high thermal emission," he said.

"The amount of energy being emitted by these eruptions implies lava fountains gushing out of fissures at a very large volume per second, forming lava flows that quickly spread over the surface of Io."

All three events, including the largest, most powerful eruption of the trio on 29 Aug. 2013, were likely characterised by "curtains of fire", as lava blasted out of fissures perhaps several miles long.

The papers, one with lead author Katherine de Kleer, a UC Berkeley graduate student, and coauthored by UC Berkeley research astronomer Máté Ádámkovics, and the other coauthored by Ádámkovics and David R. Ciardi of Caltech's NASA Exoplanet Science Institute, have been accepted for publication in the journal Icarus.

More Information: Near-infrared monitoring of Io and detection of a violent outburst on 29 August 2013 - Authors: Katherine de Kleera, Imke de Patera, Ashley Gerard Daviesd, Máté Ádámkovicsa: DOI: 10.1016/j.icarus.2014.06.006

Jupiter's moon Europa: The Importance of Plumes

Plumes on the closest of the jovian moons, Io, are a common phenomenon. Credit: NASA/JPL

The Hubble Space Telescope is famous for finding black holes.

It can pick out thousands of galaxies in a patch of sky the size of a thumbprint.

The most powerful space telescope ever built, the Hubble provided evidence that the Universe isn't slowing down in its infinite rush into whatever lies beyond.

But the Hubble's cosmic firepower was recently put to a new purpose: searching for a billowing cloud of water vapor on Jupiter's moon Europa.

The plumes are a sign that extraterrestrial life could be lurking within our own Solar System.

Before we head way out there, we need to know a little about the eruptions happening at home.

Plumes: Warm and Nearby
On Earth, the plumes are a hallmark of energy in motion. Here, active geology often takes the form of pyroclastic eruptions. Pyro is Greek for "fire," while "clastic" derives from "broken."

Pyroclastic eruptions feature solid rock, semi-solid fragments and hot gases expelled from the mantle through areas of weakness in the crust.

They create the plumes of ash and smoke we typically associate with volcanos. Even when volcanos are underwater, as many are, they send up steaming columns of lava fragments, bits of rock and heated gas.

These underwater plumes of hot material rise hundreds of meters. The heated underwater plumes that make it to the surface of the ocean can be seen from space.

While these displays are impressive, not all that explodes from the Earth's crust is pyroclastic. Geysers are long columns of water.

Their bases lie close enough to the mantle to be heated by its 1,000° C (1,832 ° F) temperatures.

The heated water expands and rises, forcing its way to the surface. Once the water and steam reach the surface, the pressure falls, as does the plume of vapour, after inertia shoots it briefly into space.

In all of these formations, heated gases escape from the interior and reach the surface. There, they rapidly expand and cool, dissipating the fierce energies that drove them to erupt.

In this way, volcanism reflects the build-up of pressure within a planet or other large body on which it is known to occur.

In March of 2006, geysers were discovered spewing water from the surface of Enceladus, one of Saturn's icy moons.

Thus began a race to explain how a moon with surface temperatures of -330° Fahrenheit (-201° Celsius) could have active geology, and to discover if those geysers could signal a warm core for Enceladus and other icy moons.

More information: "Transient Water Vapour at Europa's South Pole." Lorenz Roth, Joachim Saur, Kurt D. Retherford, Darrell F. Strobel, Paul D. Feldman, Melissa A. McGrath, and Francis Nimmo. Science 10 January 2014: 343 (6167), 171-174.Published online 12 December 2013 [DOI: 10.1126/science.1247051]

Read the full article here

Major volcanic eruption seen on Jupiter's moon Io

Voyager 1 acquired this image of Io on March 4, 1979. An enormous volcanic explosion can be seen silhouetted against dark space over Io’s bright limb. 

Credit: NASA/JPL

Recent observations of Jupiter's moon Io has revealed a massive volcanic eruption taking place 628,300,000 km (390,400,000 miles) from Earth. Io, the innermost of the four largest moons around Jupiter, is the most volcanically active object in the Solar System with about 240 active regions.

But this new one definitely caught the eye of Dr. Imke de Pater, Professor of Astronomy and of Earth and Planetary Science at the University of California in Berkeley.

She was using the Keck II telescope on Mauna Kea in Hawaii on August 15, 2013 when it immediately became apparent something big was happening at Io.

"When you are right at the telescope and see the data, this is something you can see immediately, especially with a big eruption like that," de Pater told reporters.

de Pater said this eruption is one of the top 10 most powerful eruptions that have been seen on this moon.

"It is a very energetic eruption that covers over a 30 square kilometer area," she said.

"For Earth, that is big, and for Io it is very big too. It really is one of the biggest eruptions we have seen."

She added the new volcano appears to have a large energy output. "We saw a big eruption in 2001, which was in the Surt region, which is well known as the biggest one anyone has ever seen," she said.

"For this one, the total energy is less but per square meter, it is bigger than the one in 2001, so it is very powerful."

While Io's eruptions can't be seen directly from Earth,infrared cameras on the Keck telescope (looking between 1 and 5 microns) have been able to ascertain there are likely fountains of lava gushing from fissures in the Rarog Patera region of Io, aptly named for a Czech fire deity.

While many regions of Io are volcanically active, de Pater said she's not been able to find any other previous activity that has been reported in the Rarog Patera area, which the team finds very interesting.

Ashley Davies of NASA's Jet Propulsion Laboratory in Pasadena, California and a member of the observing team told reporters that Rarog Patera was identified as a small, relatively innocuous hot spot previously in Galileo PPR data and possibly from Earth, but at a level way, way below what was seen on August 15, and reported in New Scientist.

de Pater and other astronomers will be taking more data soon with Keck and perhaps more telescopes to try and find out more about this massive eruption.

"We never know about eruptions – they can last hours, days months or years, so we have no idea how long it will stay active," she said, "but we are very excited about it."

No data or imagery has been released on the new eruption yet since the team is still making their observations and will be writing a paper on this topic.

Scientists think a gravitational tug-of-war with Jupiter is one cause of Io's intense vulcanism.

ESA and Russia Plan Probe Landing on Jupiter's Moon, Ganymede

An artist's illustration of the JUpiter ICy moons Explorer spacecraft in the Jovian system. The mission will launch in 2022 and arrive at Jupiter in 2030 to study the planet and its largest moons.

CREDIT: ESA/AOES

A Russian probe being designed to land on Ganymede, Jupiter's largest moon, could launch toward the gas giant with a European spacecraft being developed to explore Jupiter's icy ocean-covered satellites, according to European space officials.

The benefits of such a joint launch arrangement, including sharing reconnaissance and mapping from Europe's Jupiter Icy Moons Explorer (JUICE), are not lost on scientists. But more Earthly concerns, such as government finances and the realities of technical developments, could thwart the proposal.

"It all depends on if the Russians are ready to fly at the same time as us," said Alvaro Gimenez Canete, director of the European Space Agency (ESA)'s science and robotic exploration programs.

The solar system's giant
JUICE is scheduled to launch in 2022 and arrive at Jupiter in 2030, entering orbit around the huge planet and making repeated flybys of three of its largest moons — Ganymede, Callisto and Europa.

In September 2032, the European spacecraft will arrive at Ganymede, becoming the first probe to enter orbit around the moon of another planet. Equipped with radar, a mapping camera and other instruments, JUICE will measure the thickness of global ice sheets covering Jupiter's moons and produce terrain and mineral maps of Ganymede.

Such data will prove to be a rich resource not only for researchers, but also for engineers planning missions to explore Ganymede's surface and study what lies beneath the moon's crust of ice, Gimenez told reporters at the Paris Air Show this week.

"Russia's plan is to implement a Ganymede Lander, which is a very ambitious mission," said Fabio Favata, head of ESA's science planning and community coordination office, which oversees the strategic direction of the space agency's space science programs.

Favata said the Russian mission, for now known by scientists simply as the Ganymede Lander, has captured the interest of Europe's planetary science community.

An illustration of Russia's planned Ganymede lander that could explore the Jupiter moon as part of the European Space Agency's Jupiter Icy Moons Explorer mission.

CREDIT: ESA/Roscosmos

Europa or Ganymede?

Russian mission planners initially proposed the lander to target Europa, another of Jupiter's moons with a frozen crust thinner than the ice cap covering Ganymede. After a NASA mission to orbit Europa never materialized, Russia retooled the project to focus on Ganymede, falling in line with the goals of Europe's Jupiter mission.

There are numerous advantages of landing on Ganymede as opposed to Europa. The radiation environment at Ganymede is less severe than at Europa, which lies closer to Jupiter; this is one of the reasons ESA picked Ganymede as the destination for JUICE, Gimenez said.

According to presentations at a workshop hosted by Russia's Space Research Institute in Moscow in March, Russian scientists say mapping and reconnaissance of Ganymede are required before any attempted landing. Russia's concept for the mission, which assumes no international collaboration for now, includes an orbiter and a lander to be dispatched to Ganymede in 2023 or 2024.

The scope of a potential partnership between Europe and Russia on robotic Jupiter exploration ranges from no collaboration to a completely merged program in which JUICE and the Ganymede Lander would launch from Earth together on the journey into the outer solar system.

Another option — perhaps the most likely, scientists say — is a loose collaboration involving complementary scientific goals, shared development of science instruments, and the use of the JUICE mission to help select a landing site on Ganymede.

NASA Cassini Finds Hints of Geological Activity on Saturn Moon Dione

The NASA Cassini spacecraft swooped in for a close-up of the cratered, fractured surface of Saturn's moon Dione in this image taken during the spacecraft's Jan. 27, 2010, non-targeted flyby.

Image credit: NASA /JPL-Caltech /Space Science Institute.

From a distance, most of the Saturnian moon Dione resembles a bland cueball.

Thanks to close-up images of a 500-mile-long (800-kilometer-long) mountain on the moon from NASA's Cassini spacecraft, scientists have found more evidence for the idea that Dione was likely active in the past. It could still be active now.

Bonnie Buratti

"A picture is emerging that suggests Dione could be a fossil of the wondrous activity Cassini discovered spraying from Saturn's geyser moon Enceladus or perhaps a weaker copycat Enceladus," said Bonnie Buratti of NASA's Jet Propulsion Laboratory in Pasadena, Calif., who leads the Cassini science team that studies icy satellites.

"There may turn out to be many more active worlds with water out there than we previously thought."

Other bodies in the solar system thought to have a subsurface ocean - including Saturn's moons Enceladus and Titan and Jupiter's moon Europa - are among the most geologically active worlds in our solar system.

They have been intriguing targets for geologists and scientists looking for the building blocks of life elsewhere in the solar system.

The presence of a subsurface ocean at Dione would boost the astrobiological potential of this once-boring iceball.

Hints of Dione's activity have recently come from Cassini, which has been exploring the Saturn system since 2004.

This image, which is composed of data obtained by NASA's Cassini spacecraft, shows the topography of a mountain known as Janiculum Dorsa on the Saturnian moon Dione. 

Image credit: NASA/JPL-Caltech/SSI/Brown

The spacecraft's magnetometer has detected a faint particle stream coming from the moon, and images showed evidence for a possible liquid or slushy layer under its rock-hard ice crust.

Other Cassini images have also revealed ancient, inactive fractures at Dione similar to those seen at Enceladus that currently spray water ice and organic particles.

The mountain examined in the latest paper -- published in March in the journal Icarus -- is called Janiculum Dorsa and ranges in height from about 0.6 to 1.2 miles (1 to 2 kilometers).

The moon's crust appears to pucker under this mountain as much as about 0.3 mile (0.5 kilometer).

Noah Hammond

"The bending of the crust under Janiculum Dorsa suggests the icy crust was warm, and the best way to get that heat is if Dione had a subsurface ocean when the ridge formed," said Noah Hammond, the paper's lead author, who is based at Brown University, Providence, R.I.

Dione gets heated up by being stretched and squeezed as it gets closer to and farther from Saturn in its orbit.

With an icy crust that can slide around independently of the moon's core, the gravitational pulls of Saturn get exaggerated and create 10 times more heat, Hammond explained.

Other possible explanations, such as a local hotspot or a wild orbit, seemed unlikely.

Scientists are still trying to figure out why Enceladus became so active while Dione just seems to have sputtered along.

Perhaps the tidal forces were stronger on Enceladus, or maybe the larger fraction of rock in the core of Enceladus provided more radioactive heating from heavy elements.

Read more here

Windows Into Jupiter's moon Europa's Interior

This graphic of Jupiter's moon Europa maps a relationship between the amount of energy deposited onto the moon from charged-particle bombardment and the chemical contents of ice deposits on the surface in five areas of the moon (labeled A through E). 

Credit: NASA/JPL-Caltech/Univ. of Ariz./JHUAPL/Univ. of Colo.

The surface of Jupiter's moon Europa exposes material churned up from inside the moon and also material resulting from matter and energy coming from above.

If you want to learn about the deep saltwater ocean beneath this unusual world's icy shell -- as many people do, certainly those who are interested in possible extraterrestrial life -- you might target your investigation of the surface.

New analysis of observations made more than a decade ago by NASA's Galileo mission to Jupiter helps identify the deposits that have emanated from 'below' the surface rather than those deposited 'on' the surface.

In particular the report examines Sulphuric Acid Hydrate production on Europa's surface.

J. Brad Dalton

"We have found the regions where charged electrons and ions striking the surface would have done the most, and the least, chemical processing of materials emplaced at the surface from the interior ocean," said J. Brad Dalton of NASA's Jet Propulsion Laboratory, Pasadena, Calif., lead author of the report published recently in the journal Planetary and Space Science.

"That tells us where to look for materials representing the most pristine ocean composition, which would be the best places to target with a lander or study with an orbiter."

Europa is about the size of Earth's moon and, like our moon, keeps the same side toward the planet it orbits.

Picture a car driving in circles around a mountain with its left-side windows always facing the mountain.

Europa's orbit around Jupiter is filled with charged, energetic particles tied to Jupiter's powerful magnetic field.

Jupiter's Moon Io

Besides electrons, these particles include ions of sulphur and oxygen originating from volcanic eruptions on Io, a neighbouring Jupiter moon.

The magnetic field carrying these energetic particles sweeps around Jupiter faster than Europa orbits Jupiter, in the same direction: about 10 hours per circuit for the magnetic field versus about 3.6 days for Europa's orbit.

So, instead of our mountain-circling car getting bugs on the front windshield, the bugs are plastered on the back of the car by a "wind" from behind going nearly nine times faster than the car.

Europa has a "leading hemisphere" in front and a "trailing hemisphere" in back.

NASA's Galileo Satellite

Earlier studies had found more sulphuric acid hydrate being produced towards the center of the trailing hemisphere than elsewhere on Europa's surface, interpreted as resulting from chemistry driven by sulphur ions bombarding the icy surface.

Surface deposits in these areas are most likely to preserve the original chemical compounds that erupted from the interior.

Dalton suggests that any future spacecraft missions to Europa should target these deposits for study from orbit, or even attempt to land there.

Dalton stated "While investigating the products of surface chemistry driven by charged particles is still interesting from a scientific standpoint, there is a strong push within the community to characterize the contents of the ocean and determine whether it could support life. These kinds of places just might be the windows that allow us to do that."

Jupiter's Moon Europa May Have Penitentes - 'Spikes of Ice'

Europa, as viewed from NASA’s Galileo spacecraft. Visible are plains of bright ice, cracks that run to the horizon, and dark patches that likely contain both ice and dirt.

CREDIT: NASA/Ted Stryk

The equator of Jupiter's icy moon Europa may be covered with huge spikes of ice, scientists say.

Astronomers have known for some time that Jupiter's moon Europa is icy, and now scientists are trying to understand just what form that ice takes by using some of the coldest places on Earth as analogues.

Huge ice spikes, known as penitents, found on Earth could form on Europa, they said.

Dan Hobley

"It's a pretty obscure geological feature on the Earth," Dan Hobley, an astronomer at the University of Virginia, reported after he presented his findings at the 44th annual Lunar and Planetary Science Conference.

The 3.3 to 16.4 foot (1 to 5 meter) spikes of ice only grow in certain parts of the Andes mountains on Earth, but those areas of the world serve as good proxies for what Europa's geology might be like, Hobley said.

It takes a very specific set of circumstances for penitentes to form, Hobley said.

The angle of the sun has to hit the ice in just the right way to keep the spikes of ice standing on end and buried deep into the ground.

The blades grow in very dry conditions and can thrive in dirt-filled or clean circumstances.

As far as scientists can tell right now, all of those environments exist along Europa's equator, Hobley said.

These bizarre ice and snow formations are known as penitentes (Spanish for 'penitents'). 

They are illuminated by the light of the Moon, which is visible on the right on the photograph. 

On the left, higher in the sky, the Large and Small Magellanic Clouds can be faintly seen, while the reddish glow of the Carina Nebula appears close to the horizon on the far left. 

Photo by ESO Photo Ambassador Babak Tafreshi.

Although Europa has been observed using radar and spectroscopy, scientists have not been able to understand exactly what the surface of this moon looks like.

The geological features of Europa seem "basically random," Hobley said, but the existence of penitentes could offer an explanation.

Scientists have found that Europa's equator is warmer than it should be, and penitentes could explain that mysterious temperature, Hobley said.

The ice spines reflect heat onto one another, creating a warmer area because the sunlight gets trapped bouncing from ice spike to ice spike, Hobley explained.

The scientist and his colleagues are interested in understanding what the surface of Europa looks like, partially because it's a first step towards designing a viable lander that could safely touch down on the moon's frozen surface.

But it might not be that simple, Hobley said.

The icy shell of Europa's surface might shift occasionally, displacing the area of the alien world that used to be its equator.

Penitentes don't naturally form in higher latitudes, so if the shell does shift, that could create a problem for astronomers trying to map exactly where to set down a lander.

"We're at the state where this is a good, solid guess," Hobley said.

Russian Ganymede Lander Mission more difficult than expected

Russia's proposed landing mission to Ganymede was discussed extensively last week at an international meeting hosted by the Space Research Institute of the Russian Academy of Sciences.

The mission to explore, and perhaps to drill, the Solar system's largest moon, presumably in close cooperation with the European Space Agency (ESA), would be a major challenge for Russia's space and science industries.

The project is generally approved, but success is far from assured.

The mission to Ganymede, now better known by the simple name of "Ganymede Lander", is the latest reincarnation of Russia's contribution to the Laplas project, promoted by the European Space Agency (ESA) in the early 2000s.

With Laplas becoming the single-spacecraft project JUICE (JUpiter ICy moon Explorer, until christened officially), Russian plans have also undergone major changes, although their main objective, sending a lander to Jupiter's biggest moon, remained intact.

The initial aim was to explore Europa, a smaller Jovian moon, where there is an ocean of liquid water beneath its frozen surface (around 10 km thick) and is therefore considered a good prospect for the exploration of habitable conditions.

Ganymede also holds liquid water, but much deeper, under an icy crust of around 130-150 km. On the other hand, this moon is farther from Jupiter with less radiation than Europa, putting spacecraft at a much lower risk.

However, the main argument for shifting to Ganymede was that the European mission now no longer plans to stay near Europa long enough to provide the high resolution images needed to select a landing site.

It is supposed now that the JUICE orbiting spacecraft will provide the Russian lander with preliminary reconnaissance data and perhaps act as a communication relay station for data sent between Ganymede and Earth.

Hence, the current scenario is that the European mission is developing independently while Russia's landing spacecraft has its own scientific payload and objectives.

As the success of the landing relies on many technical issues closely concerned with JUICE, the Russian equipment and goals must be taken into account from the start when designing the eventual lander.

A more detailed mission scenario was presented by Maksim Martynov, deputy general designer of the S.A. Lavochkin Association and head of the design bureau.

Following the "play safe" rule, it is supposed that Russia will send two spacecraft to Ganymede, a lander and a small additional orbiter to secure the landing site as a back-up option to information from JUICE.

Even though launched simultaneously from a Proton launcher, they will arrive separately. After reconnaissance and remote studies of the moon, the lander will be delivered to the surface to begin its studies.

The start is planned for 2022-23 with the completion in 2029-30 (JUICE is currently scheduled for 2022) and subsequent arrival on Ganymede within a few months.

NASA Mission to Jupiter's Moon Europa

Though NASA is devoting many of its exploration resources to Mars these days, the agency still has its eye on an icy moon of Jupiter that may be capable of supporting life as we know it.

Last week, NASA officials announced that they plan to launch a $1.5 billion rover to Mars in 2020, adding to a string of Red Planet missions already on the docket.

The Curiosity rover just landed this past August, for example, and an orbiter called Maven and a lander named InSight are slated to blast off in 2013 and 2016, respectively.

But NASA is also thinking about ways to investigate the possible habitability of Europa, Jupiter's fourth-largest moon.

One concept that may be gaining traction is a so-called "clipper" probe that would make multiple flybys of the moon, studying its icy shell and suspected subsurface ocean as it zooms past.

Complex and beautiful patterns adorn the icy surface of Jupiter's moon Europa, as seen in this colour image intended to approximate how the satellite might appear to the human eye. 

The data used to create this view were acquired by NASA's Galileo spacecraft in 1995 and 1998. 

CREDIT: NASA/JPL/Ted Stryk

"We briefed [NASA] headquarters on Monday, and they responded very positively," mission proponent David Senske, of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., said here Dec. 7 at the annual fall meeting of the American Geophysical Union (AGU).

The $2 billion unmanned Europa Clipper, which could be ready to launch by 2021, would also do vital reconnaissance work for a potential lander mission in the future, Senske reported.