Mysterious Pits in Mars Crater

This fascinating observation shows us a dark-toned mound with pits inside an impact crater (http://static.uahirise.org/images/201...). Are these pits the result of sublimation? The crater itself is an ancient one, as evidenced by the eroded rim. For the mound inside, HiRISE resolution can give us a closer look at textural features that might help explain what we're looking at: layers in pit walls, or perhaps cracks from expansion?

 

This Is How The Private Sector Will Put A Lander On The Moon

In an effort to win the $20 million Google Lunar X-Prize, Astrobotic and Masten have been busy at work developing a free-flying moon lander. Watch this video of the XOMBIE rocket as it uses an onboard hazard avoidance system to execute a perfect landing.

Indeed, NASA's free-flying Morpheus landeris not the only game in town. Thanks to theGoogle Lunar X-Prize, there are no less than ten teams vying to be the first among them to send a probe to the moon, move it a third of a mile, and then transmit a hi-def video back to Earth.

 

On February 21, 2014, Astrobiotic and Masten tested the hazard avoidance capabilities of the autolanding sensor in a flight aboard XOMBIE. Amazingly, the sensors can detect rocks and craters as small as a soccer ball.

Source: io9

We've Found A Hidden Ocean On Enceladus That May Harbor Life

It's turning out that the outer reaches of the solar system may be more hospitable to life than we ever imagined. Gravity measurements made by Cassini have confirmed that Enceladus, a tiny moon orbiting Saturn, hosts a subsurface ocean in its southern latitudes. Astronomers are now saying it's potentially habitable.

The idea that Enceladus may host a subsurface ocean is nothing new. Back in 2005, NASA's Cassini spacecraft beamed back images showing what appeared to be plumes of water vapor spewing out from fractures, called "tiger stripes," near the icy moon's southern pole (similar to what was recently detected on Europa, another icy moon with a subsurface ocean). By itself, these plumes didn't prove that liquid water existed under the ice. It's conceivable, for example, that massive tectonic forces exerted by Saturn's gravity was creating friction along the plates of ice, resulting in cracks and the jettisoning of liquid water.

But now, after an analysis of gravity measurements made by Cassini from 2010 to 2012, astronomers have confirmed that a large reservoir of liquid water exists underneath Enceladus's icy surface. And just as importantly, they've confirmed that the tiny moon is a differentiated celestial body; it's comprised of two layers — an external icy layer and an internal rocky core made up of silicates. Excitingly, this layer of silicate rock, in conjunction with liquid water, means that Enceladus features a potentially habitable environment — one that could be even more hospitable to life than Europa.

A Negative Gravity Anomaly

Geophysical data provided by Cassini revealed a rather strange thing about Enceladus. The moon's southern region featured a negative gravity anomaly. These anomalies exist when there's less mass in a particular region that what would be expected in an otherwise uniform spherical body. Enceladus has a depression on its surface at the south pole, so scientists were expecting to find this negative mass anomaly. But what they weren't expecting to find was one so large; it was considerably bigger than what would be predicted by the depression alone.

What this suggested to the astronomers, a team consisting of Luciano Iess of Sapienza University of Rome and David Stevenson, a professor of Planetary Science at Caltech, is that a denser mass must exist under the surface to compensate. And because water is denser than ice, the only reasonable explanation is that liquid water resides underneath.

The Southern Reservoir

Unlike Europa and its global subsurface ocean, Enceladus has an ocean in the southern regions. It extends from the south pole in all directions to about 50 degrees south — about half-way to the equator. This ocean is deepest near the south pole. Astronomers haven't ruled out the possibility of something larger, but the current data does not support it.

Enceladus, which is only 310 miles (500 km) in diameter, features a large water reservoir about 18 to 25 miles (30 to 40 km) beneath the icy surface. This liquid layer is about 5 to 6 miles (8 to 10 km) deep. Its total water volume is similar to that of Lake Superior's — the largest of the Great Lakes.

That Enceladus can host liquid water comes as somewhat of a surprise. The surface temperature of the moon is -180 degrees C (-292 degrees F). Speaking at a press conference yesterday, Stevenson conjectured that Saturn's intense gravitational forces are likely responsible for creating the required energy. Alternately, there could be some kind of internal energy source. Enceladus's small size may account for its partial ocean (Europa is much bigger — about the size of our moon).

The scientists aren't entirely sure why the ocean is located in the south, but it's likely that the flexing and heating of the ice is pronounced in the polar regions — a process that feeds back on itself creating increasing amounts of lubrication.

As for the plumes, they're probably caused by tidal forces that are flexing and heating the ice. A kind of plumbing system likely connects the ocean through the cracks to the surface.

The Importance of Silicates to Life

As noted, Enceladus features a rocky core made up of silicates and at a density of about 2.4 grams per cubic centimeter. This is exciting for astrobiologists because silicate provides many materials essential for life, such as phosphorous and sulphur. And in fact, scientists have already detected evidence of salts and organic molecules in the plumes and near the tiger stripes. Because the water is in contact with silicates in the presence of energy, chemical reactions are possible. Taken together, this means that Enceladus is — in the words of the researchers — "an attractive place to look for life."

Interestingly, astronomers don't know if Europa hosts organic molecules or silicates (water ice in contact with liquid water behaves much differently). But Enceladus does. This means that Enceladus may actually be a better candidate for life than Europa.

Indeed, one of the main take-aways from this research is that potentially habitable environments are emerging in completely unexpected places. In time, the outer solar system may yield a cornucopia of life-friendly environments. Given that Titan, Callisto and Ganymede may also host subsurface oceans (still unconfirmed), a certain kind of "habitablezone for outer gas giants" may actually exist — though the potential for these remote regions to foster the development of intelligent life is unknown and likely at an extremely low probability.

Next Steps

Looking ahead, astronomers would like to gain a better understanding of the moon's interior structure. They'd like to know the exact location, size, and shape of the reservoir that supplies the jets. Measuring gravity anomalies will continue to inform this research.

As for future missions, spectrographic measurements of the plumes could yield more insights into the molecular makeup of the water.

Source: io9

Read the entire study at Science: "The Gravity Field and Interior Structure of Enceladus."

Mars One Finalists Prepare for Life on the Red Planet

Mars One, a nonprofit organization that links donors with private aerospace companies in hopes of building a Martian colony in 2023 (and then turning it into a reality TV show), sounds too weird to be true—but it has big names, big money, and a realistic-looking plan of action behind it. They haven’t yet picked out the 24 people who will take a one-way ticket to Mars and spend the rest of their lives there, but that part shouldn’t be a problem; over 200,000 candidates have applied, and they’ve whittled the list down to 1,058 finalists.

Mars One has a nice promo/solicitation-for-funds video here which explains the process, perhaps best summed up by the phrase “completely implausible-sounding idea that kind of makes sense when you look at it step by step”:

So while they get the other hardware (and funding) in line, how exactly do they plan to eliminate 98% of the finalists from the candidate pool? By sticking them in Mars-ish simulations right here on Earth, allowing prospective colonists to experience all the comforts of the rugged Martian frontier with none of the existential horror that one might reasonably expect to encounter after being stranded on Mars.

Source: MU

A Realistic Video of What You'd See Flying Through Deep Space

This is a 3D visualization of the Hubble Deep Field image, and it gives you a tantalizing glimpse of what it might be like to fly at extreme speeds through the vast regions between galaxies.

The HubbleSite has made several 3D visualizations of deep space images available on a special area of their site, and it's worth watching all of them — they are glorious. Plus, they offer a complete explanation of what you're seeing and how the visualization was created, sometimes from non-visual data. Here's what they have to say about the Deep Field image:

In 2004, the Hubble Ultra Deep Field (HUDF) provided a ground-breaking view of distant galaxies. In 2009, those data were augmented with new infrared observations to create the HUDF-IR. In 2012, the Hubble eXtreme Deep Field (HXDF) combined those images along with a complete census of archival datasets to see yet farther into the universe. The HXDF contains roughly 5,500 galaxies stretching over 13 billion light-years of space, and represents astronomy's deepest view into the cosmos.

This scientific visualization depicts a flight through the HXDF galaxies. Using measured and estimated distances for approximately 3,000 galaxies, astronomers and visualizers constructed a three-dimensional model of the galaxy distribution. The camera traverses through the thirteen-billion-light-year dataset and ends in blackness, not because more distant galaxies do not exist, but because such galaxies have not yet been observed. For cinematic reasons, the exceedingly vast distances in the 3D model have been significantly compressed.

The visualization is credited to F. Summers, L. Frattare, T. Davis, Z. Levay, and G. Bacon (STScI); data was crunched by G. Illingworth, P. Oesch, and D. Magee (UCSC).

Here's another astonishingly beautiful flyby, this time of the Horsehead Nebula:

The Horsehead Nebula is a dark cloud of dense gas and dust located just below the belt of Orion on the sky. A visible light view shows a strong silhouette resembling the horse's head used for a knight in chess. Infrared light, however, reveals a more complex scene, as shown in Hubble's 2013 image. The warm parts of the clouds glow in infrared light, plus longer infrared wavelengths can penetrate deeper into the clouds. A dark and relatively featureless scene is revealed as a glowing gaseous landscape.

This video presents a scientific visualization of the Horsehead Nebula as seen in infrared light. To fill out the widescreen frame, the central Hubble image has been augmented by ground-based observations from the European Southern Observatory's Visible and Infrared Survey Telescope for Astronomy (VISTA). The three-dimensional interpretation has been sculpted to create a wispy and mountainous environment, with stars distributed in an approximate and statistical manner. The computer graphics model is intended to be scientifically reasonable, but not fully accurate. This imaginative traverse provides an inspiring spaceflight experience that brings the celestial scene to life.

Source: io9