Building Blocks for Life on Mars Possibly Seen By Viking Probes, Study Suggests

Samples of Mars dirt collected by NASA's Viking Mars landers back in the 1970s may have contained carbon-based chemical building blocks of life as we know it, a new study suggests.


During their missions, the two Viking landers vaporized Martian dirt and scrutinized the samples for signs of organic - or carbon-based - molecules that could serve as the raw ingredients for life. At the time, all they found were chlorine compounds attributed to contamination, but the new research suggests the Viking probes' heat-treatment may have generated these chlorine compounds from naturally occurring Martian organics, destroying them in the process.

"This doesn't say anything about the question of whether or not life has existed on Mars, but it could make a big difference in how we look for evidence to answer that question," study co-author Chris McKay, of NASA's Ames Research Center in Moffett Field, Calif., said in a statement.

Organic molecules can come from non-biological or biological sources. Meteorites raining on Mars and Earth for the past 5 billion years contain organics, so even if Mars has never supported life, scientists before the Viking missions expected Martian dirt to contain at least some organics, researchers have said.


New evidence from Phoenix

The new study follows a 2008 discovery made by the Phoenix Mars Lander. In its roughly five months on Mars, Phoenix found a chlorine-containing chemical called perchlorate in the Martian dirt.

In the lab, the research team for the new study added perchlorate to some desert dirt from Chile that was known to contain organics. Then they heated the soil up, mimicking the Viking landers' organics-detection test. They found the same two organic chlorine compounds the Vikings did: chloromethane and dichloromethane.

What's the connection between these three chemicals? Perchlorate becomes a strong oxidant when heated, breaking down naturally occurring organics into chloromethane and dichloromethane.

"Our results suggest that not only organics, but also perchlorate, may have been present in the soil at both Viking landing sites," the study's lead author, Rafael Navarro-González of the National Autonomous University of Mexico, said in a statement.

"[Perchlorate] could sit there in the Martian soil with organics around it for billions of years and not break them down, but when you heat the soil to check for organics, the perchlorate destroys them rapidly," McKay said.

Challenging old theories

The new study, in the current issue of the Journal of Geophysical Research – Planets, may inspire scientists to reconsider the results of the Viking mission.

The Viking landers performed several different tests on Martian surface material in 1976. They found no compelling evidence for life, or even for the existence of organic molecules.

But subsequent studies have questioned what these tests actually showed. Researchers replicating Viking's methods on Earth, for example, failed to detect signs of life in Earth soil teeming with microbes.

More than three decades ago, the two Viking landers scooped up some Martian dirt and heated it to 500 degrees Celsius (932 degrees Fahrenheit). The chlorine compounds they found were interpreted at the time as contaminants from cleaning fluids.

"The lack of organics was a big surprise from the Vikings," McKay said. "But for 30 years we were looking at a jigsaw puzzle with a piece missing. Phoenix has provided the missing piece: perchlorate. The perchlorate discovery by Phoenix was one of the most important results from Mars since Viking."

Trying to resolve the question

Upcoming Mars missions and further work on meteorites from Mars could help resolve whether Viking actually found evidence of organics on the Red Planet.



Curiosity, a rover that NASA's Mars Science Laboratory mission will deliver to Mars in 2012, will range far and wide, analyzing a broad range of rocks and dirt samples. Its instruments will check for organics in Martian dirt and powdered rocks by baking samples to even higher temperatures than Viking did and by using an alternative liquid-extraction method at much lower heat.

Combining these techniques on a range of samples may help test the new study's idea that heated-up perchlorates could have destroyed organics in the Viking tests.

The European-led ExoMars mission, set to launch in 2018, will include a rover with the ability to dig about 6.5 feet (2 meters) below the Martian surface. The chances of finding complex molecules, including evidence of life such as proteins, are better underground, where molecules are protected from harsh ultraviolet radiation.

Starburst Galaxy Unleashes Gassy 'Superwind'

A striking galaxy buzzing with energetic star formation takes center stage in a new photograph that showcases an unusual "superwind" of out-flowing gas, researchers say.

The starburst galaxy NGC 4666, located about 80 million light-years away from Earth, is a hotbed of intense star formation, which is thought to be caused by gravitational interactions between NGC 4666 and its neighboring galaxies, one of which is visible in the lower left of the new photo. [See the galaxy NGC 4666 photo]

Gravitational interactions between galaxies often trigger the type of rigorous star formation seen in NGC 4666.

Strong winds from the massive stars inside NGC 4666, combined with supernova explosions, drive a robust flow of gas – a so-called "superwind" – from the galaxy into space, according to the European Southern Observatory where astronomers took the new photo.

The superwind originates in the bright central region of the galaxy and extends for tens of thousands of light-years. Astronomers think the cosmic wind could be blowing at speeds of up to a few thousands of kilometers every second, said astronomer Jörg Dietrich of the University of Michigan. The new photo of the galaxy was part of follow-up observations for an earlier study by Dietrich and his colleagues.

"Observing superwinds directly is difficult because the gas in them is very tenuous," Dietrich told SPACE.com in an e-mail. "However, these winds push denser and colder gas out, which is easier to observe."

The gas is very hot and emits radiation mostly in the form of X-rays and in the radio part of the spectrum, which cannot be seen in visible light images.

This new image of NGC 4666 was made in visible light with the Wide Field Imager on the MPG/ESO 2.2-meter telescope at the La Silla Observatory in Chile, which is part of the European Southern Observatory.

The galaxy had previously been observed in X-rays by the European Space Agency's XMM-Newton space telescope, and this image was taken to allow further study of other objects that had been detected in the earlier X-ray observations.

One such object is a faint galaxy cluster that can be seen close to the bottom edge of the image, to the right of center. This cluster, serendipitously found from the XMM-Newton observations, is much farther away from Earth than NGC 4666, at a distance of about 3 billion light-years.

In studying astronomical objects, researchers must observe them at several wavelengths, as light at different wavelengths can show different physical processes that are taking place.

Guts of Exploded Star Revealed

A wave of "star guts" ejected into space from the supernova explosion of a massive dying star has been spotted by the Hubble Space Telescope.

The new supernova image allows astronomers to measure the velocity and composition of the former star's debris, which scientists are calling cosmic "guts," as it interacts with the surrounding environment. [Photo of the supernova star guts.]

The new study, led by Kevin France, a research associate at the Center for Astrophysics and Space Astronomy at the University of Colorado in Boulder, targeted the remnants of Supernova 1987A, which was first discovered in 1987.

France and his colleagues observed the interaction between the stellar explosion and the circumstellar material around the former star – forming what looks like a "string of pearls." A new video of SN1987A illustrates the odd formation.

The glowing ring of gas that measures 6 trillion miles (9.6 trillion km) in diameter encircles the supernova remnant and is energized by X-rays. These "pearls" of circumstellar material are made up of material that was emitted before the star exploded, as it was preparing to die.

The shock waves from the supernova have been brightening some 30 to 40 pearls in the ring. As the stellar debris interacts with the circumstellar material over time, the pearls will eventually form a continuous glowing circle around the remnant.

SN1987A is about 150,000 light-years away from Earth on the outskirts of the Tarantula Nebula in the Large Magellanic Cloud, the nearest galaxy to our own Milky Way.

The age of the original star that set off the explosion remains unclear, but is estimated to be between 5 million and 10 million years.

Analyzing supernovas is important because their intense energy may also trigger much larger cosmic interactions, and could be responsible for regulating the physical state and long-term evolution of galaxies, France said.

"In the big picture, we are seeing the effect a supernova can have in the surrounding galaxy, including how the energy deposited by these stellar explosions changes the dynamics and chemistry of the environment," said he added. "We can use this new data to understand how supernova processes regulate the evolution of galaxies."

The Incredible Shrinking Moon

(Simply stated, the moon is shrinking.

According to a recent scientific study, including images taken by NASA's Lunar Reconnaissance Orbiter, or the LRO, the lunar surface has revealed a series of geologic faults that weren't seen before.
These small faults, which are caused by internal cooling of the moon, have been discovered all over the moon, said Thomas Watters, a planetary geologist at the Center for Earth and Planetary Studies of the Smithsonian National Air and Space Museum in Washington, D.C.

"We know it's shrinking by looking at these landforms called lobate scarps that kind of look like stairsteps in the landscape," Watters told AOL News. "They're caused by thrust faults, which are generated when the lunar crust material is pushed together and pushed up, forming a cliff or scarp."

What excites scientists is that the LRO camera's high-resolution images reveal details down to a half meter to 2 meters per pixel resolution, and this is how Watters and his colleagues have been able to detect the scarps all over the moon.

But the biggest discovery about these structures, Watters added, points to the fact that the moon is still active.

"These faults could be so young that they may be indicating very, very recent tectonic and, therefore, geologic activity on the moon. One of the general conceptions out there is that the moon is this geologically dead body, and that's really not the case," he said.

Exactly how much lunar shrinkage are we talking about? And since the moon is directly involved with the rising and falling of global sea levels, should we be getting into panic mode down here on Earth at the idea of a smaller moon?

"Overall, it's only about 100 meters in the past billion years, so it's not a whole lot of contraction -- it's not something you're ever going to notice from Earth," Watters said. "But because the scarps are widespread, they definitely indicate the moon's crust has been shrinking.

"The mass of the moon hasn't changed; the overall size of the moon has changed slightly and become slightly smaller. Therefore, the tidal effects on Earth are exactly the same."

These lunar scarp structures were initially discovered in images photographed by several Apollo missions during the 1970s. But the LRO cameras now reveal how widespread the scarps are on the moon.

In the cosmic scheme of things, Watters wants to reassure us that there's no cause for alarm to Earthlings.

"No, absolutely not. The moon is not shrinking away. There's no fear that if you don't get out there and see the moon today, in the next cycle, it won't be there."

The complete details of Watters' study can be found in today's edition of the journal Science.

Amazingly Fast Eruption on the Sun Photographed

One of the fastest big solar eruptions in years has been observed streaking away from the sun at more than 2.2 million mph by two NASA spacecraft.

The flare occurred Aug. 1 and created a massive sun eruption called a coronal mass ejection that struck Earth's magnetic field Tuesday, creating dazzling aurora displays. NASA's twin STEREO spacecraft recorded the eruption and beamed images of the sun storm back to Earth. [Photo of the sun eruption.]

The material ejected from the sun was seen speeding toward Earth at more than 1,000 kilometers per second, or just over 2.2 million mph (3.6 million kph). Another wave from the event was expected to hit Earth's magnetic field on Wednesday. NASA's two STEREO spacecraft, which monitor the sun's weather in 3-D, also recorded a video of the sun eruption.

"These kinds of eruptions are one of the first signs that the sun is waking up and heading toward another solar maximum expected in the 2013 time frame," NASA officials said in a statement. The sun goes through a regular 11-year activity cycle. The last solar maximum occurred in 2001 and its recent extreme solar minimum was particularly weak and long-lasting, the space agency added.

Coronal mass ejections are eruptions of charged particles from the sun that stream out over several hours. They can contain several billion tons of plasma and expand away from the sun at speeds of up to 1 million mph (1.6 million kph). At such speeds, they can cross the 93 million-mile (150 million-km) gulf between the Earth and sun in two to four days.

The material belched from the sun during the Aug. 1 flare is not expected to cause any disturbances on Earth other than creating spectacular auroras. Auroras are created when charged particles are caught by Earth's magnetic field and interact with the atmosphere above the poles.

The Aug. 1 solar flare was a moderate C-class flare. The coronal mass ejection it set off created a strong so-called geomagnetic storm that lasted nearly 12 hours – enough time for auroras to spread from Europe to North America, NASA officials said in a statement.

Stronger solar storms could cause adverse impacts to space-based assets and technological infrastructure on Earth.

Solar Tsunami? Look Up Tonight for a Grand Show

A solar storm could make tonight a great night for stargazing.

The sun's surface erupted early Sunday and sent tons of plasma into space, according to the Harvard-Smithsonian Center for Astrophysics. It's headed toward Earth, which could be in for a beautiful light show.

"This eruption is directed right at us, and is expected to get here early in the day on August 4th," astronomer Leon Golub of the astrophysics center, said in a statement. "It's the first major Earth-directed eruption in quite some time."

Some publications have dubbed it a "solar tsunami."

Solar Dynamics Observatory / NASA

A pair of huge eruptions from the sun, such as this one spotted in April, has created a mass of plasma that that is now racing toward the earth.

The eruption, called a coronal mass ejection, was captured by a NASA camera. Depending on its path, it could make the northern lights, or aurora borealis, visible tonight.

"When a coronal mass ejection reaches Earth, it interacts with our planet's magnetic field, potentially creating a geomagnetic storm," Golub said. Solar particles "collide with atoms of nitrogen and oxygen in the atmosphere, which then glow like miniature neon signs."

Residents of the northern U.S. and other nations should look to the north tonight and early Wednesday to see rippling "curtains" of green and red light, Golub said. While aurorae can usually only be seen at high latitudes, they also can be on display at more southern points during a geomagnetic storm, Golub said.
Cities, because of their bright lights, aren't good places to see the show, Golub told The Boston Globe.
Scientists will get an idea of when the lights can be seen after the eruption passes by a satellite, the Globe said. They will know about an hour ahead of time.

Nuclear Bombs Could Save Earth from Asteroids

"The nuclear bomb is the strongest bomb we know," said Dearborn, who presented his study last month at the 216th meeting of the American Astronomical Society in Miami, Fl. "It's about 3 million times more efficient than chemical bombs. The question is how to use that energy."


The Lawrence Livermore National Laboratory, a research facility founded by the University of California, has programs that design and test nuclear weapons. [Top 10 Weapons in History]
Nuclear bangs in space

Dearborn believes that powerful nuclear explosives could be used to change the orbit of an asteroid heading for Earth, causing it to miss our planet and avoid a potentially devastating impact.
But, that nuclear option is most effective in circumstances where there are only a few years notice, said David Morrison, director of the NASA Lunar Science Institute and senior scientist for Astrobiology at NASA's Ames Research Center at Moffett Field, Calif., who has done extensive research on asteroid and comet impact hazards.
"If we have an asteroid that is really large, and we don't have more than a few years notice, nuclear is probably all we can do," Morrison told SPACE.com. "If it's a mile or smaller and we have 10 to 20 years warning, we probably won't go nuclear."
In such cases, scientists could opt to impact the asteroid with a ballistic rocket, sending the cosmic interloper off course.
At the moment, there is probably very little difference in terms of accuracy for both the nuclear method and ballistic method, said Morrison. But if using ballistic rockets to divert asteroids can be tested, it is possible that this technique could be more precise.
"If we test the ballistic impact, as people have proposed doing, then we can make it much more accurate than a nuke," he said.
But will it really work?
In fact, the ability to test these methods is one of the main sources of contention.
"One of the problems with the nuclear alternative is that I don't think anyone will ever let us test it," Morrison explained. "I think it would arouse considerable opposition from the public, because people are very nuclear averse. That's the thing about David Dearborn and I – we don't disagree about the facts at all. I'm just a little less anxious to embed the public relations problem."
Some of the issues that have affected previous ideas on how to divert asteroids have been due to the extremely low levels of gravity present on asteroids.
"If you were to watch an asteroid go by in space, it would look like a tumbling dog bone," Dearborn said. "On a one kilometer (0.62 mile) asteroid, a 200-pound person would weigh about 1/10th of an ounce. So, proposals that people have made for how to divert them have encountered problems with how you give a push to an asteroid."
NASA is now aiming to send astronauts to visit an asteroid by 2025 to get a first-hand look at them. The mission is part of the space agency's new space exploration plan proposed by President Barack Obama.
Additionally, a European spacecraft, Rosetta, will be gliding past asteroid Lutetia on July 10 to get some close-up views of the space rock. Scientists are hoping that the observations from the flyby will contribute to the relatively small body of knowledge about asteroids.
Blowing up asteroids
According to Dearborn, blowing up an asteroid – or fragmenting it – using powerful nuclear explosives could be the most effective way of diverting it.
For one, nuclear fusion is vastly more efficient per unit of mass, compared to chemical fuel. So, from a practicality standpoint, it would be easier to transport this type of energy into deep space for an asteroid-diverting mission.
"You can carry an awful lot of energy for a very small amount of mass," Dearborn said. "As long as payload – the ability to lift things and get them to deep space – is significant, this is a way of transporting enough energy to do the job."
The sheer power of nuclear explosives also makes it a good candidate for such a task.
Dearborn discussed a previous proposal to use a powerful laser beam to repeatedly zap an asteroid in order to alter its course. While this could be a feasible option, Dearborn said, the timescale needed to carry out such an operation using current technology is too large.
For example, using a beam from the National Ignition Facility to deliver enough energy would require 5 million pulses which would have to be delivered over the course of approximately 6,000 years.
To effectively fragment and divert an asteroid, its orbit must be pushed by at least a centimeter per second. To do this, about five to 10 kilotons of energy input is needed, regardless of the method.
"The nice thing about any kind of intervention is that you only have to make it miss the Earth," Dearborn said. "A very small change in its orbital period will do that."
But wait, there's more
Still, the problem does not end with simply blowing up an asteroid.

Fragmenting an asteroid creates a debris field, and it is important to account for these remains in such a way that only a fraction of the debris is able to pass through the Earth's atmosphere.

Dearborn created simulations to examine the amount of energy and time needed to most effectively divert an asteroid and disperse its debris field in such a way as to minimize collisions with Earth.
He found that intersecting a 270-meter body asteroid with a 300 kiloton energy source at the surface could safely be done 15 days out from impact.
"If you can intersect it 15 days out, which is beyond the orbit of the moon, that would be fine," Dearborn said. "It was enough that 97 percent of that material missed Earth."
Furthermore, if the explosion occurs far enough into space, debris should be less of a concern, said Morrison.
"If you're going to do this 100 million miles away from Earth, it shouldn't be too much of a problem," Morrison said. "There'll be a little bit of debris, but by the time it gets close to us, it would be pretty dispersed."
Asteroid sentinels on alert
Dearborn is continuing to experiment with models and simulations that attempt to determine the amount of time needed to act for different size asteroids.
And while Dearborn states that a truly disastrous impact with Earth is possible, the chances of such an occurrence remain slim.
"There will be another large impact resulting in global catastrophe any mega-year now," he said. "But, a million years is a really long time."
The Spaceguard Survey Report from NASA's Ames Space Science Division, which was an effort to study near-Earth objects, has done extremely well in locating large objects that could cause mass extinction.
"We've found more than 90 percent of those," Morrison said. "In a few more years, we'll be able to say that there's nothing out there to cause a global catastrophe. But, there'll be a million that will be big enough to wipe out an entire city. It'll take a long time, if ever, to find them and figure out their orbits."
Technological advancements in ground-based and space telescopes should assist scientists in their study of near-Earth objects and other potential hazards, but the threat will likely be omnipresent, since smaller objects will always be more difficult to track down.
"The bottom line is, we could be hit by one of those small ones at any time, with no warning at all," Morrison said. "Right now, I can say almost nothing about the probability of one of those small objects hitting us, because we simply haven't found all of them."
Still, in the event that an asteroid crashes toward Earth, particularly with only a few years warning, nuclear explosives may be our best option, both scientists agree.

"With current technology and enough time, we should be able to divert large bodies," Dearborn said. "Right now, it is the only technology that we have that has the energy to move large bodies.

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