Pluto's Hidden Ocean - New Horizons

An artist's concept of the New Horizons spacecraft as it visits Pluto in 2015.

Instruments will map Pluto and its moon, Charon, providing detail not only on the surface of the dwarf planet, but also about its shape, which could reveal whether or not an ocean lies beneath the ice. 

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

When NASA's New Horizons cruises by Pluto in 2015, the images it captures could help astronomers determine if an ocean is hiding under the frigid surface, opening the door to new possibilities for liquid water to exist on other bodies in the solar system.

New research has not only concluded such an ocean is likely, but also has highlighted features the spacecraft could identify that could help confirm an ocean's existence.

Pluto's outer surface is composed of a thin shell of nitrogen ice, covering a shell of water ice.

Planetary scientists Guillaume Robuchon and Francis Nimmo, both of the University of California at Santa Cruz, wanted to find out whether or not an ocean could exist underneath this icy shell, and what visible signs such an ocean might produce on the surface.

The pair modeled the thermal evolution of the dwarf planet and studied the behavior of the shell to see how the surface would be affected by the presence of an ocean below.

Searching the surface
Ironically, the easiest feature to identify would appear if no ocean existed. As spherical bodies spin, their angular momentum tends to push material towards the equator, forming a bulge.

If Pluto boasts a liquid layer, the ice would flow, reducing such a protrusion. Thus, the appearance of a "frozen-in"primordial bulge, left over from when Pluto spun more rapidly, would signify a lack of ocean.

"If the bulge is present, it will be about 6 miles (10 km) high, so it should be readily detectable," Nimmo said. New Horizons project scientist Hal Weaver agreed on the last point.

"New Horizon imaging will measure the shape of Pluto very accurately."

Icy Lake of Water on Jupiter's Moon Europa

The icy moon Europa rising above Jupiter’s cloud tops. The picture was one of a handful of the Jupiter system that New Horizons took primarily for artistic, rather than scientific, value.

CREDIT: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Data from a NASA planetary mission have provided scientists evidence of what appears to be a body of liquid water, equal in volume to the North American Great Lakes, beneath the icy surface of Jupiter's moon, Europa.

The data suggest there is significant exchange between Europa's icy shell and the ocean beneath. This information could bolster arguments that Europa's global subsurface ocean represents a potential habitat for life elsewhere in our solar system. The findings are published in the scientific journal Nature.

"The data opens up some compelling possibilities," said Mary Voytek, director of NASA's Astrobiology Program at agency headquarters in Washington.

"However, scientists worldwide will want to take a close look at this analysis and review the data before we can fully appreciate the implication of these results."

NASA's Galileo spacecraft, launched by the space shuttle Atlantis in 1989 to Jupiter, produced numerous discoveries and provided scientists decades of data to analyse.

Galileo studied Jupiter, which is the most massive planet in the solar system, and some of its many moons.

One of the most significant discoveries was the inference of a global salt water ocean below the surface of Europa.

This ocean is deep enough to cover the whole surface of Europa and contains more liquid water than all of Earth's oceans combined.

However, being far from the sun, the ocean surface is completely frozen. Most scientists think this ice crust is tens of miles thick.

"One opinion in the scientific community has been if the ice shell is thick, that's bad for biology. That might mean the surface isn't communicating with the underlying ocean," said Britney Schmidt, lead author of the paper and postdoctoral fellow at the Institute for Geophysics, University of Texas at Austin.

"Now, we see evidence that it's a thick ice shell that can mix vigorously and new evidence for giant shallow lakes. That could make Europa and its ocean more habitable."

Schmidt and her team focused on Galileo images of two roughly circular, bumpy features on Europa's surface called chaos terrains.

Based on similar processes seen on Earth -- on ice shelves and under glaciers overlaying volcanoes -- they developed a four-step model to explain how the features form.

The model resolves several conflicting observations. Some seemed to suggest the ice shell is thick. Others suggest it is thin.

This recent analysis shows the chaos features on Europa's surface may be formed by mechanisms that involve significant exchange between the icy shell and the underlying lake.

This provides a mechanism or model for transferring nutrients and energy between the surface and the vast global ocean already inferred to exist below the thick ice shell. This is thought to increase the potential for life there.

NASA-Funded Scientists Make Lunar Discovery of Water

A team of NASA-funded researchers has measured for the first time water from the moon in the form of tiny globules of molten rock, which have turned to glass-like material trapped within crystals.

Data from these newly-discovered lunar melt inclusions indicate the water content of lunar magma is 100 times higher than previous studies suggested.

The inclusions were found in lunar sample 74220, the famous high-titanium "orange glass soil" of volcanic origin collected during the Apollo 17 mission in 1972.

The scientific team used a state-of-the-art ion microprobe instrument to measure the water content of the inclusions, which were formed during explosive eruptions on the moon approximately 3.7 billion years ago.

The results, published in the May 26 issue of Science Express, raise questions about aspects of the "giant impact theory" of how the moon was created.

That theory predicted very low water content of lunar rock due to catastrophic degassing during the collision of Earth with a Mars-sized body very early in its history. The study also provides additional scientific justification for returning similar samples from other planetary bodies in the solar system.

"Water plays a critical role in determining the tectonic behavior of planetary surfaces, the melting point of planetary interiors and the location and eruptive style of planetary volcanoes," said Erik Hauri, a geochemist with the Carnegie Institution of Washington and lead author of the study.

"I can conceive of no sample type that would be more important to return to Earth than these volcanic glass samples ejected by explosive volcanism, which have been mapped not only on the moon but throughout the inner solar system."

In contrast to most volcanic deposits, the lunar melt inclusions are encased in crystals that prevent the escape of water and other volatiles during eruption.

"These samples provide the best window we have on the amount of water in the interior of the moon where the orange glass came from," said science team member James Van Orman of Case Western Reserve University in Cleveland.

There's Metal In Moon Water

Bring a filter if you plan on drinking water from the moon.

Water ice recently discovered in dust at the bottom of a crater near the moon's south pole is accompanied by metallic elements like mercury, magnesium, calcium, and even a bit of silver.

Now you can add sodium to the mix, according to Dr. Rosemary Killen of NASA's Goddard Space Flight Center in Greenbelt, Md.

Recent discoveries of significant deposits of water on the moon were surprising because our moon has had a tough life.

Intense asteroid bombardments in its youth, coupled with its weak gravity and the Sun's powerful radiation, have left the moon with almost no atmosphere. This rendered the lunar surface barren and dry, compared to Earth.

However, due to the moon's orientation to the Sun, scientists theorized that deep craters at the lunar poles would be in permanent shadow and thus extremely cold, and able to trap volatile material like water as ice if such material were somehow transported there, perhaps by comet impacts or chemical reactions with hydrogen, a major component of the solar wind.

The October 9, 2009 impact of NASA's Lunar CRater Observation and Sensing Satellite (LCROSS) spacecraft into the permanently shadowed region of the Cabeus crater confirmed that a surprisingly large amount of water ice exists in this region, along with small amounts of many other elements, including metallic ones.

Enceladus: Saturn's Icy Moon May Keep Oceans Liquid With Wobble

At least four distinct plumes of water ice spew out from the south polar region of Saturn's moon Enceladus in this dramatically illuminated image. Image credit: NASA/JPL/Space Science Institute

Saturn's icy moon Enceladus should not be one of the most promising places in our solar system to look for extraterrestrial life. Instead, it should have frozen solid billions of years ago.

Located in the frigid outer solar system, it's too far from the sun to have oceans of liquid water - a necessary ingredient for known forms of life - on its surface.

Some worlds, like Mars or Jupiter's moon Europa, give hints that they might harbour liquid water beneath their surfaces. Mars is about 4,200 miles across and Europa almost 2,000 miles across.

However, with a diameter only slightly more than 500 miles, Enceladus just doesn't have the bulk needed for its interior to stay warm enough to maintain liquid water underground.

With temperatures around 324 degrees below zero Fahrenheit, the surface of Enceladus is indeed frozen. However, in 2005 NASA's Cassini spacecraft discovered a giant plume of water gushing from cracks in the surface over the moon's south pole, indicating that there was a reservoir of water beneath the ice.

Analysis of the plume by Cassini revealed that the water is salty, indicating the reservoir is large, perhaps even a global subsurface ocean. Scientists estimate from the Cassini data that the south polar heating is equivalent to a continuous release of about 13 billion watts of energy.

To explain this mysterious warmth, some scientists invoke radiation coupled with tidal heating. As it formed, Enceladus (like all solar system objects) incorporated matter from the cloud of gas and dust left over from our sun's formation. In the outer solar system, as Enceladus formed it grew as ice and rock coalesced.

If Enceladus was able to gather greater amounts of rock, which contained radioactive elements, enough heat could have been generated by the decay of the radioactive elements in its interior to melt the body.

Moon Has 100 Times More Water

Moon Has 100 Times More Water, New Study Suggests

A moon rock brought to Earth by Apollo 11, humans' first landing on the moon in July 1969, is shown as it floats aboard the International Space Station.

Part of Earth can be seen through the window. The 3.6 billion year-old lunar sample was flown to the station in honor of the July 2009 40th anniversary of the historic first moon landing.

It will be returned on shuttle mission STS-128 to be publicly displayed. Credit: NASA

The moon's interior may harbor 100 times more water than previous estimates, according to a new study that took a fresh look at samples of moon rocks collected by Apollo astronauts nearly 40 years ago.

The researchers determined that the lunar water likely originated early in the moon's formation history, suggesting that it is, in fact, native to the moon.

Scientists at the Carnegie Institution's Geophysical Laboratory, and other colleagues, said it's likely that the water was preserved from the hot magma that was present when the moon began to form – some 4.5 billion years ago.

They also think that the water, which is locked up in lunar rocks and material, is likely more widespread in the moon's interior than previous studies estimated. These findings now suggest that the lower limit for total water on the moon could be 100 times greater.

"When the rocks were first returned from the Apollo missions, it was pretty obvious that they were really dry," Francis McCubbin, lead author of the study, told SPACE.com. "A lot of people attributed the dry nature to something fundamental about how the moon formed. I think an estimate was thrown out there of less than 1 part per billion (ppb) water, because the presumption was that there was almost no water on the moon."

Tracking moon water

In 2008, research of volcanic glass beads brought attention to the fact that there might be more water in the moon's interior than scientists had previously thought. At the time, McCubbin and his colleagues were searching for water in lunar minerals, but at that point they had only models and calculations that suggested higher water content.

Since then, observations from unmanned probes from NASA and other space agencies have confirmed the presence of water in lunar material and water ice on the moon's surface.

For this new study, the researchers were able to compare their calculations to analyses of samples of Apollo moon rocks and a lunar meteorite from Africa.

"We combined the measurements with models that characterize how the material crystallized as the moon cooled," McCubbin said. "We found that the minimum water content ranged from 64 parts per billion to 5 parts per million – at least two orders of magnitude greater than previous results."