NASA's Curiosity Mars Rover: Organics Possibly Present

This image illustrates possible ways methane might be added to Mars' atmosphere (sources) and removed from the atmosphere (sinks). 

NASA's Curiosity Mars rover has detected fluctuations in methane concentration in the atmosphere, implying both types of activity occur on modern Mars. 

Credit: NASA/JPL-Caltech/SAM-GSFC/Univ. of Michigan

NASA's Curiosity Mars rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory's drill.

"This temporary increase in methane, sharply up and then back down, tells us there must be some relatively localized source," said Sushil Atreya of the University of Michigan, Ann Arbor, and Curiosity rover science team.

"There are many possible sources, biological or non-biological, such as interaction of water and rock."

Researchers used Curiosity's onboard Sample Analysis at Mars (SAM) laboratory a dozen times in a 20-month period to sniff methane in the atmosphere.

During two of those months, in late 2013 and early 2014, four measurements averaged seven parts per billion.

Before and after that, readings averaged only one-tenth that level.

Curiosity also detected different Martian organic chemicals in powder drilled from a rock dubbed 'Cumberland', the first definitive detection of organics in surface materials of Mars.

These Martian organics could either have formed on Mars or been delivered to Mars by meteorites.

Organic molecules, which contain carbon and usually hydrogen, are chemical building blocks of life, although they can exist without the presence of life.

Curiosity's findings from analyzing samples of atmosphere and rock powder do not reveal whether Mars has ever harboured living microbes, but the findings do shed light on a chemically active modern Mars and on favorable conditions for life on ancient Mars.

"We will keep working on the puzzles these findings present," said John Grotzinger, Curiosity project scientist of the California Institute of Technology in Pasadena (Caltech).

"Can we learn more about the active chemistry causing such fluctuations in the amount of methane in the atmosphere? Can we choose rock targets where identifiable organics have been preserved?"

Researchers worked many months to determine whether any of the organic material detected in the Cumberland sample was truly Martian.

Curiosity's SAM lab detected in several samples some organic carbon compounds that were, in fact, transported from Earth inside the rover.

However, extensive testing and analysis yielded confidence in the detection of Martian organics.

Exomoons Could Be Abundant Sources Of Habitability

Europa is one of the moons in our solar system that could host life. 

What about beyond the solar system? 

Credit: NASA/JPL/Ted Stryk

With about 4,000 planet candidates from the Kepler Space Telescope data to analyze so far, astronomers are busy trying to figure out questions about habitability.

What size planet could host life? How far from its star does it need to be? What would its atmosphere need to be made of?

Look at our own solar system, however, and there's a big gap in the information we need. Most of the planets have moons, so surely at least some of the Kepler finds would have them as well. Tracking down these tiny worlds, however, is a challenge.

A new paper in the journal Astrobiology, called "Formation, Habitability, and Detection of Extrasolar Moons," goes over this mostly unexplored field of extrasolar research.

The scientists do an extensive literature review of what is supposed about moons beyond the Solar System, and they add intriguing new results.

A wealth of moons exist in our own solar system that could host life. Icy Europa, which is circling Jupiter, was recently discovered to have plumes of water erupting from its surface.

Titan, in orbit around Saturn, is the only known moon with an atmosphere, and could have the precursor elements to life in its hydrocarbon seas that are warmed by Saturn's heat.

Other candidates for extraterrestrial hosts include Jupiter's moons Callisto and Ganymede, as well as Saturn's satellite Enceladus.

Lead author René Heller, an astrophysicist at the Origins Institute at McMaster University, in Ontario, Canada, said some exomoons could be even better candidates for life than many exoplanets.

"Moons have separate energy sources," he said. "While the habitability of terrestrial planets is mostly determined by stellar illumination, moons also receive reflected stellar light from the planet as well as thermal emission from the planet itself."

Moreover, a planet like Jupiter, which hosts most of the moons in the Solar System that could support life, provides even more potential energy sources, he added.

The planet is still shrinking and thereby converts gravitational energy into heat, so that it actually emits more light than it receives from the Sun, providing yet more illumination.

Besides that, moons orbiting close to a gas giant are flexed by the planet's gravity, providing potential tidal heating as an internal, geological heat source.

Finding the first exomoon

The first challenge in studying exomoons outside our Solar System is to actually find one. Earlier this year, NASA-funded researchers reported the possible discovery of such a moon, but this claim was ambiguous and can never be confirmed.

That's because it appeared as a one-time event, when one star passed in front of another, acting as a sort of gravitational lens that amplified the background star.

Two objects popped out in the gravitational lens in the foreground, either a planet and a star, or a planet and an extremely heavy exomoon.

For his part, Heller is convinced that exomoons are lurking in the Kepler data, but they have not been discovered yet.

Only one project right now is dedicated to searching for exomoons, and is led by David Kipping at the Canadian Space Agency.

His group has published several papers investigating 20 Kepler planets and candidates in total. The big restriction to their efforts is computational power, as their simulations require supercomputers.

Triton’s odd, melted appearance hint that the moon was captured and altered by Neptune. 

Credit: NASA

Another limiting factor is the number of observatories that can search for exomoons.

To detect them, at least a handful of transits of the planet-moon system across their common host star would be required to absolutely make sure that the companion is a moon, Heller said.

Also, the planet with the moon would have to be fairly far from its star, and decidedly not those close-in hot Jupiters that take only a few days to make an orbit. In that zone, the gravitational drag of the star would fatally perturb any moon's orbit.

Heller estimates that a telescope would need to stare constantly at the same patch of sky for several hundred days, minimum, to pick up an exomoon.

Kepler fulfilled that obligation in spades with its four years of data gazing at the same spot in the sky, but astronomers will have to wait again for that opportunity.

Because two of Kepler's gyroscopes (pointing devices) have failed, Kepler's new mission will use the pressure of the Sun to keep it steady, but it can only now point to the same region of the sky for about 80 days at at time because the telescope will periodically need to be moved so as not to risk placing its optics too close to the Sun.

NASA's forthcoming Transiting Exoplanet Survey Satellite is only expected to look at a given field for 70 days.

In the future, the European Space Agency's PLAnetary Transits and Oscillations of stars (PLATO) will launch in 2024 for what is a planned six-year mission looking at several spots in the sky.

"PLATO is the next step, with a comparable accuracy to Kepler but a much larger field of view and hopefully a longer field of view coverage," Heller said.

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Canada funds Non-Nuclear sources for Medical Isotopes

Canada expects to be able to make enough medical isotopes through non-nuclear methods by 2016 to replace those now produced by an aging reactor and better assure an uninterrupted supply for medical imaging, a government minister said on Thursday.

To that end, the federal government will fund three research institutes developing cyclotron and linear accelerator technologies for production of isotopes on a commercial scale, Natural Resources Minister Joe Oliver said.

Canada's only current source of the isotopes is a problem-plagued reactor at Atomic Energy of Canada Ltd's facility at Chalk River, Ontario.

The reactor is licensed to run until 2016. "Our challenge now is to prove that cyclotron and linear accelerator production can be commercially viable. ... We envision a future where isotope production will no longer require highly enriched uranium — a weapons-grade material," he said.

The government will give a total of C$25 million ($24.3 million) to the three facilities for this goal.

Asked if there would be a gap between the end of production by the Chalk River reactor and the supplies from the other sources, Oliver said he did not think so, since the technology was proven and what remained was commercialization.

"That's been worked on for a while," he told reporters after making the announcement. "It's reached a fairly robust stage right now. We're talking about increasing the amount ... and we're comfortable we can meet those objectives by 2016."

Chalk River facility

Oliver also announced Canada wanted a private operator to run the Chalk River facility, a move that would take two years to accomplish.

The temporary closure of the Chalk River reactor for safety reasons in 2007 and then again from May 2009 to August 2010 caused a medical challenge and a political furor as the government scrambled to find isotope replacements internationally.

The closures dealt a blow to Nordion Inc, which as a major supplier of isotopes relied on Chalk River. Nordion had no immediate comment on Thursday's announcement.

AECL had built two more modern prototype reactors to make isotopes but eventually mothballed them after a series of problems. An arbitration panel last year rejected Nordion's claim for damages against AECL.

A CANDU Nuclear Facility

Oliver said the government was not seeking to close down or sell the Chalk River nuclear laboratories.

In October 2011 Canada sold AECL's Candu nuclear reactor division to a subsidiary of SNC Lavalin Group Inc.

Alternative Energy Sources: Surfactant driven propulsion

A small autonomous boat powered by a volatile surfactant has been developed by scientists in Finland and Israel.

The surfactant modifies the surface tension of the liquid it floats on to create a surface tension gradient that propels the boat forward.

Propulsion induced by a surface tension gradient is known as Marangoni propulsion. It’s used in nature by small creatures such as Microvelia (small aquatic insects) to give a burst of speed to escape predators.

In man-made devices, the Marangoni effect has been used to power small ‘camphor boats’ and ‘soap boats’; however, these systems normally offer only short term propulsion or require the boat to be confined to specific channels.

To develop a longer-term propulsion system, the team led by Robin Ras at Aalto University, Finland, created a boat from a lightweight membrane made from a nano-cellulose aerogel.

The membrane is impermeable to water (and oil) but it allows the gaseous surfactants to pass through it. The team used ethanol as the fuel to power a boat floating on water.

Housed in a reservoir at the rear of the boat, a few drops of ethanol are placed on a tissue. As the ethanol evaporates, it diffuses through the membrane at the rear of the boat and lowers the surface tension of the water.

This creates the surface tension gradient that drives the boat forward. The boat is not steered so it typically travels in a circular route.

Once the boat has passed, the ethanol at the water surface evaporates, returning the surface tension to normal. Modifying the surface tension only requires a small amount of surfactant.

‘The boat ran for over 54 minutes on only 25 microlitres of fuel,’ says Ras. ‘It’s very fuel efficient while cruising at a speed of 2cm s^-1,’ he adds. To demonstrate the generality of their approach, the team showed they could also use pentane to power a boat floating on paraffin oil.

‘This is a beautiful illustration of exciting soft matter research. The researchers combine innovative materials science with fundamental surface science to construct a novel self-propelling floating device that is much more controllable and versatile than any similar device suggested before,’ says Lennart Piculell, an expert in physical chemistry at Lund University, Sweden.

‘I don't see any immediate applications, but the concept is simple and can be applied to even smaller devices.’