Solar System: Life began on Mars - Boron and Molybdenum

New evidence has emerged which supports the long-debated theory that life on Earth may have started on Mars.

Professor Steven Benner will tell geochemists gathering today (Thursday 29 Aug) at the annual Goldschmidt conference that an oxidized mineral form of the element molybdenum, which may have been crucial to the origin of life, could only have been available on the surface of Mars and not on Earth.

"In addition", said Professor Benner "recent studies show that these conditions, suitable for the origin of life, may still exist on Mars."

"It's only when molybdenum becomes highly oxidized that it is able to influence how early life formed," explains Professor Benner, from The Westheimer Institute for Science and Technology in the USA.

"This form of molybdenum couldn't have been available on Earth at the time life first began, because three billion years ago the surface of the Earth had very little oxygen, but Mars did. It's yet another piece of evidence which makes it more likely life came to Earth on a Martian meteorite, rather than starting on this planet."

The research Professor Benner will present at the Goldschmidt conference tackles two of the paradoxes which make it difficult for scientists to understand how life could have started on Earth.

The first is dubbed by Professor Benner as the 'tar paradox'. All living things are made of organic matter, but if you add energy such as heat or light to organic molecules and leave them to themselves, they don't create life. Instead, they turn into something more like tar, oil or asphalt.

"Certain elements seem able to control the propensity of organic materials to turn into tar, particularly boron and molybdenum, so we believe that minerals containing both were fundamental to life first starting," says Professor Benner.

"Analysis of a Martian meteorite recently showed that there was boron on Mars; we now believe that the oxidized form of molybdenum was there too."

The second paradox is that life would have struggled to start on the early Earth because it was likely to have been totally covered by water.

Not only would this have prevented sufficient concentrations of boron forming – it's currently only found in very dry places like Death Valley – but water is corrosive to RNA, which scientists believe was the first genetic molecule to appear.

Although there was water on Mars, it covered much smaller areas than on early Earth.

"The evidence seems to be building that we are actually all Martians; that life started on Mars and came to Earth on a rock," says Professor Benner.

"It's lucky that we ended up here nevertheless, as certainly Earth has been the better of the two planets for sustaining life. If our hypothetical Martian ancestors had remained on Mars, there might not have been a story to tell."

More information: goldschmidt.info/2013/

ULA Delta 4: US Largest Rocket Launches Top-Secret Spy Satellite

A United Launch Alliance (ULA) Delta 4 Heavy rocket carrying a payload for the National Reconnaissance Office (NRO) lifted off from Space Launch Complex-6 here at 11:03 a.m. PDT today. 

Designated NROL-65, the mission is in support of national defense. This is ULA’s eighth launch in 2013, the 24th Delta 4 mission and the second Delta 4 Heavy launch from Vandenberg Air Force Base.

Credit: Pat Corkery/United Launch Alliance

The United States' largest rocket launched a spy satellite on a hush-hush mission Wednesday (Aug. 28).

An unmanned Delta 4-Heavy rocket lifted off the pad at California's Vandenberg Air Force Base at 2:03 p.m. EDT (1803 GMT) Wednesday, carrying a classified payload to a polar orbit for the U.S. National Reconnaissance Office (NRO).

"Today's launch is dedicated to the men and women who serve for our nation's freedom," a commentator said a few minutes into the liftoff.

It's unclear what intelligence the spacecraft, which is known as NROL-65, will collect as it zips around our planet. Because of the clandestine nature of the mission, it entered a planned media blackout about seven minutes after liftoff.

"We are truly honored to deliver this critical asset to orbit," said Jim Sponnick, United Launch Alliance vice president for the Atlas and Delta Programs. "The ULA Delta 4 Heavy is currently the world's largest rocket, providing the nation with reliable, proven, heavy lift capability for our country’s national security payloads from both the east and west coasts."

The Delta 4 Heavy, which is built by ULA and first flew in 2004, is the biggest and most powerful American rocket in operation today. The 235-foot-tall (72 meters) launcher generates about 2 million pounds of thrust at liftoff, according to ULA officials.

ESA VLT: Oldest solar twin identified

This image tracks the life of a Sun-like star, from its birth on the left side of the frame to its evolution into a red giant star on the right. 

On the left the star is seen as a protostar, embedded within a dusty disc of material as it forms. It later becomes a star like our Sun. 

After spending the majority of its life in this stage, the star's core begins to gradually heat up, the star expands and becomes redder until it transforms into a red giant. 

Following this stage, the star will push its outer layers into the surrounding space to form an object known as a planetary nebula, while the core of the star itself will cool into a small, dense remnant called a white dwarf star. 

Marked on the lower timeline are where our Sun and solar twins 18 Sco and HIP 102152 are in this life cycle. 

The Sun is 4.6 billion years old and 18 Sco is 2.9 billion years old, while the oldest solar twin is some 8.2 billion years old -- the oldest solar twin ever identified. 

By studying HIP 102152, we can get a glimpse of what the future holds for our Sun. 

This image is illustrative; the ages, sizes, and colours are approximate (not to scale). The protostar stage, on the far left of this image, can be some 2000 times larger than our Sun. 

The red giant stage, on the far right of this image, can be some 100 times larger than the Sun. 

Credit: ESO/M. Kornmesser

An international team led by astronomers in Brazil has used ESO's Very Large Telescope to identify and study the oldest solar twin known to date.

Located 250 light-years from Earth, the star HIP 102152 is more like the Sun than any other solar twin—except that it is nearly four billion years older.

This older, but almost identical, twin gives us an unprecedented chance to see how the Sun will look when it ages.

The new observations also provide an important first clear link between a star's age and its lithium content, and in addition suggest that HIP 102152 may be host to rocky terrestrial planets.

Astronomers have only been observing the Sun with telescopes for 400 years—a tiny fraction of the Sun's age of 4.6 billion years.

It is very hard to study the history and future evolution of our star, but we can do this by hunting for rare stars that are almost exactly like our own, but at different stages of their lives.

Now astronomers have identified a star that is essentially an identical twin to our Sun, but 4 billion years older—almost like seeing a real version of the twin paradox in action.

Jorge Melendez (Universidade de São Paulo, Brazil), the leader of the team and co-author of the new paper explains: "For decades, astronomers have been searching for solar twins in order to know our own life-giving Sun better.

But very few have been found since the first one was discovered in 1997. We have now obtained superb-quality spectra from the VLT and can scrutinise solar twins with extreme precision, to answer the question of whether the Sun is special."

The team studied two solar twins—one that was thought to be younger than the Sun (18 Scorpii) and one that was expected to be older (HIP 102152).

They used the UVES spectrograph on the Very Large Telescope (VLT) at ESO's Paranal Observatory to split up the light into its component colours so that the chemical composition and other properties of these stars could be studied in great detail.

They found that HIP 102152 in the constellation of Capricornus (The Sea Goat) is the oldest solar twin known to date.

It is estimated to be 8.2 billion years old, compared to 4.6 billion years for our own Sun. On the other hand 18 Scorpii was confirmed to be younger than the Sun—about 2.9 billion years old.

More information: This research was presented in a paper to appear in "High precision abundances of the old solar twin HIP 102152: insights on Li depletion from the oldest Sun", by TalaWanda Monroe et al. in the Astrophysical Journal Letters. Research paper PDF

NASA's Mars Curiosity MSL debuts autonomous navigation

This mosaic of images from the Navigation Camera (Navcam) on NASA's Mars rover Curiosity shows the scene from the rover's position on the 376th Martian day, or sol, of the mission (Aug. 27, 2013). (Click on the image to see bigger version)

The images were taken right after Curiosity completed the first drive during which it used autonomous navigation on unknown ground. 

Credit: NASA/JPL-Caltech

NASA's Mars rover Curiosity has used autonomous navigation for the first time, a capability that lets the rover decide for itself how to drive safely on Mars.

This latest addition to Curiosity's array of capabilities will help the rover cover the remaining ground en route to Mount Sharp, where geological layers hold information about environmental changes on ancient Mars.

The capability uses software that engineers adapted to this larger and more complex vehicle from a similar capability used by NASA's Mars Exploration Rover Opportunity, which is also currently active on Mars.

Using autonomous navigation, or autonav, Curiosity can analyze images it takes during a drive to calculate a safe driving path. This enables it to proceed safely even beyond the area that the human rover drivers on Earth can evaluate ahead of time.

On Tuesday, Aug. 27, Curiosity successfully used autonomous navigation to drive onto ground that could not be confirmed safe before the start of the drive.

This was a first for Curiosity. In a preparatory test last week, Curiosity plotted part of a drive for itself, but kept within an area that operators had identified in advance as safe.

"Curiosity takes several sets of stereo pairs of images, and the rover's computer processes that information to map any geometric hazard or rough terrain," said Mark Maimone, rover mobility engineer and rover driver at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

"The rover considers all the paths it could take to get to the designated endpoint for the drive and chooses the best one."

The drive on Tuesday, the mission's 376th Martian day, or "sol," took Curiosity across a depression where ground-surface details had not been visible from the location where the previous drive ended.

The drive included about 33 feet (10 meters) of autonomous navigation across hidden ground as part of a day's total drive of about 141 feet (43 meters).

"We could see the area before the dip, and we told the rover where to drive on that part. We could see the ground on the other side, where we designated a point for the rover to end the drive, but Curiosity figured out for herself how to drive the uncharted part in between," said JPL's John Wright, a rover driver.

NASA's Mars rover Curiosity left the "Glenelg" area on July 4, 2013, on a "rapid transit route" to the entry point for the mission's next major destination, the lower layers of Mount Sharp. 

As of Aug. 27, 2013, NASA's Mars rover Curiosity has driven about 0.86 mile (1.39 kilometers) since leaving Glenelg, with about 4.46 miles (7.18 kilometers) remaining to get to the entry point. 

The rover's drive on Aug. 27, the 376th sol (Martian day) of the mission, was the first Curiosity drive using the rover's autonomous navigation capability to safely drive beyond the area that rover drivers on Earth could evaluate from images before the drive. 

The rover can analyze stereo images that it takes during the drive and choose the best path to continue driving. 

Credit: NASA/JPL-Caltech/Univ. of Arizona

Curiosity is nearly two months into a multi-month trek from the "Glenelg" area, where it worked for the first half of 2013, to an entry point for the mission's major destination: the lower layers of a 3-mile-tall (5-kilometer-tall) mound called Mount Sharp.

The latest drive brought the distance traveled since leaving Glenelg to 0.86 mile (1.39 kilometers). The remaining distance to the Mount Sharp entry point is about 4.46 miles (7.18 kilometers) along a "rapid transit route."

That route was plotted on the basis of images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.

The actual driving route, which will be based on images from Curiosity's own cameras, could be longer or shorter.

Curiosity's science team has picked a few waypoints along the rapid transit route to Mount Sharp where driving may be suspended for a few days for science.

The rover has about 0.31 mile (500 meters) left to go before reaching the first of these waypoints, which appears from orbiter images to offer exposed bedrock for inspection.

"Each waypoint represents an opportunity for Curiosity to pause during its long journey to Mount Sharp and study features of local interest," said Curiosity Project Scientist John Grotzinger of the California Institute of Technology, Pasadena.

"These features are geologically interesting, based on HiRISE images, and they lie very close to the path that provides the most expeditious route to the base of Mount Sharp.

We'll study each for several sols, perhaps selecting one for drilling if it looks sufficiently interesting."

After landing inside Gale Crater in August 2012, Curiosity drove eastward to the Glenelg area, where it accomplished the mission's major science objective of finding evidence for an ancient wet environment that had conditions favorable for microbial life.

The rover's route is now southwestward. At Mount Sharp, in the middle of Gale Crater, scientists anticipate finding evidence about how the ancient Martian environment changed and evolved.

Micro Ion Thrusters: The newest little idea for nanosat micro rockets

L. Brad King's prototype of a ferrofluid ion thruster. When subjected to voltage, the points of the crown arise from a ring-shaped trench circling a one-inch block of aluminum. 

Credit: L. Brad King

Nanosatellites are smartphone-sized gadgets that can perform simple, yet valuable, space missions.

Dozens of these little spacecraft are now tirelessly orbiting the earth performing valuable missions for NASA, the Department of Defense and even private companies.

Nano-satellites borrow many of their components from terrestrial gadgets: miniaturized cameras, wireless radios and GPS receivers that have been perfected for hand-held devices are also perfect for spacecraft.

However, according to Michigan Technological University's Lyon Brad King, there is at least one technology need that is unique to space: "Even the best smartphones don't have miniaturized rocket engines, so we need to develop them from scratch."

Miniature rockets aren't needed to launch a nano-satellite from Earth. The small vehicles can hitchhike with a regular rocket that is going that way anyway.

But because they are hitchhikers, these nano-satellites don't always get dropped off in their preferred location.

Once in space, a nano-satellite might need some type of propulsion to move it from its drop-off point into its desired orbit. This is where the micro rocket engine comes in.

For the last few years, researchers around the world have been trying to build such rockets using microscopic hollow needles to electrically spray thin jets of fluid, which push the spacecraft in the opposite direction.

The fluid propellant is a special chemical known as an ionic liquid. A single thruster needle is finer than a human hair, less than one millimeter long and produces a thrust force equivalent to the weight of a few grains of sand.

A few hundred of these needles fit in a postage-stamp-size package and produce enough thrust to maneuver a nano-satellite.

Lyon Brad King

These new electrospray thrusters face some design challenges, however. "Because they are so small and intricate, they are expensive to make, and the needles are fragile," says King, the 'Ron and Elaine Starr' Professor of Mechanical Engineering-Engineering Mechanics.

"They are easily destroyed either by a careless bump or an electrical arc when they're running."

To get around the problem, King and his team have developed an elegant strategy: eliminate the expensive and tedious micro-fabrication required to make the needles by letting Mother Nature take care of the assembly.

"We're working with a unique type of liquid called a ferro-fluid that naturally forms a stationary pattern of sharp tips in the liquid surface," he says.

"Each tip in this self-assembling structure can spray a jet of fluid just like a micro-needle, so we don't actually have to make any needles."

Ferro-fluids have been around since the 1960s. They are made of tiny magnetic particles suspended in a solvent that moves when magnetic force is applied.

King illustrates with a tiny container holding a ferro-fluid made of kerosene and iron dust. The fluid lies flat until he puts a magnet beneath it.

Then suddenly, the liquid forms a regular series of peaks reminiscent of a mountain range.

These peaks remain perfectly stable despite vigorous shaking and even turning the container upside down. It is, nonetheless, completely liquid, as a finger-tip touch proves undeniably.

When the magnet is removed, the liquid relaxes to a perfectly flat surface.

King's team was trying to make an ionic liquid that behaved like a ferro-fluid when they learned about a research team at the University of Sydney that was already making these substances.

The Sydney team was using magnetic nanoparticles made by the life-sciences company Sirtex, which are used to treat liver cancer. "They sent us a sample, and we've used it to develop a thruster," King said.

"Now we have a nice collaboration going. It's amazing that the same technology used to treat cancer can also function as a micro rocket for spacecraft."

King's first thruster is made of a one-inch block of aluminum containing a small ring of the special fluid. When a magnet is placed beneath the block, the liquid forms a tiny, five-tipped crown.

Their thruster isn't ready to push a satellite around in orbit just yet. "First we have to really understand what is happening on a microscopic level, and then develop a larger prototype based on what we learn," King said.

"We're not quite there yet; we can't build a person out of liquid, like the notorious villain from the Terminator movies. But we're pretty sure we can build a rocket engine."

NASA's Spitzer Image Carina Nebula: Brighter Than a Thousand Thousand Suns

This new view shows the Carina nebula as seen in a new image made by NASA's Spitzer Space Telescope. 

At the center of the nebula lies Eta Carinae, one of the most massive stars in the galaxy. 

Its blinding glare sculpts and destroys the surrounding nebula.

Eta Carinae represents a true giant of a star. 

It contains 100 times the mass of our sun, and burns its nuclear fuel so quickly that it blazes at least one million times brighter than the sun. 

It has brightened and faded over the years, and some astronomers think it could explode as a supernova in the not-too-distant future.

ISS NASA Spacesuit Leak: Problem recreated - Video

ISS astronauts Luca Parmitano and Chris Cassidy tested the suit aboard the International Space Station and found that the helmet continues to leak water. The cause is still under investigation.

Credit: NASA