Intro to External Pulsed Plasma Propulsion (EPPP)

Future Engine

External Pulsed Plasma Propulsion (EPPP)  is something that’s been discussed for some time. In fact, it was originally proposed by Stanislaw Ulam way back in 1947. Unfortunately the public perception of atomic technology as well as pieces of otherwise well meaning legislation have called into question the feasibility of spacecraft that operate using this advanced principle. Read More →

New Estimate of Amount of Water on Surface of Mars

Mars_Science_Laboratory_Curiosity_rover

NASA’s rover Curiosity, which landed on the surface of Mars on 6 August 2012, has led to more detailed estimates of the amount of water on the Martian surface. The Finnish Meteorological Institute is part of the NASA research team. Read More →

Could Life Have Survived a Fall to Earth?

Asteroid impacting Earth's oceans. Credit: NASA/Don Davis

Asteroid impacting Earth’s oceans. Credit: NASA/Don Davis

It sounds like science fiction, but the theory of panspermia, in which life can naturally transfer between planets, is considered a serious hypothesis by planetary scientists. The suggestion that life did not originate on Earth but came from elsewhere in the universe (for instance, Mars), is one possible variant of panspermia. Planets and moons were heavily bombarded by meteorites when the Solar System was young, throwing lots of material back into space. Meteorites made of Mars rock are occasionally found on Earth to this day, so it is quite plausible that simple life forms like yeasts or bacteria could have been carried on them. Read More →

Meteorites May Reveal Mars’ Secrets of Life

Life

In an effort to determine if conditions were ever right on Mars to sustain life, a team of scientists, including a Michigan State University professor, has examined a meteorite that formed on the red planet more than a billion years ago.

And although this team’s work is not specifically solving the mystery, it is laying the groundwork for future researchers to answer this age-old question.

The problem, said MSU geological sciences professor Michael Velbel, is that most meteorites that originated on Mars arrived on Earth so long ago that now they have characteristics that tell of their life on Earth, obscuring any clues it might offer about their time on Mars.

“These meteorites contain water-related mineral and chemical signatures that can signify habitable conditions,” he said. “The trouble is by the time most of these meteorites have been lying around on Earth they pick up signatures that look just like habitable environments, because they are. Earth, obviously, is habitable.

“If we could somehow prove the signature on the meteorite was from before it came to Earth, that would be telling us about Mars.”

Specifically, the team found mineral and chemical signatures on the rocks that indicated terrestrial weathering – changes that took place on Earth. The identification of these types of changes will provide valuable clues as scientists continue to examine the meteorites.

“Our contribution is to provide additional depth and a little broader view than some work has done before in sorting out those two kinds of water-related alterations – the ones that happened on Earth and the ones that happened on Mars,” Velbel said.

Image Credit: Michigan State University

Image Credit: Michigan State University

The meteorite that Velbel and his colleagues examined – known as a nakhlite meteorite – was recovered in 2003 in the Miller Range of Antarctica. About the size of a tennis ball and weighing in at one-and-a-half pounds, the meteorite was one of hundreds recovered from that area.

Velbel said past examinations of meteorites that originated on Mars, as well as satellite and Rover data, prove water once existed on Mars, which is the fourth planet from the sun and Earth’s nearest Solar System neighbor.

“However,” he said, “until a Mars mission successfully returns samples from Mars, mineralogical studies of geochemical processes on Mars will continue to depend heavily on data from meteorites.”

Velbel is currently serving as a senior fellow at the Smithsonian Institution’s National Museum of Natural History in Washington D.C.

The research is published in Geochimica et Cosmochimica Acta (citation below), a bi-weekly journal co-sponsored by two professional societies, the Geochemical Society and the Meteoritical Society.

Source: Michigan State University

Reference:

Stopar, J., Taylor, G., Velbel, M., Norman, M., Vicenzi, E., & Hallis, L. (2013). Element abundances, patterns, and mobility in Nakhlite Miller Range 03346 and implications for aqueous alteration Geochimica et Cosmochimica Acta, 112, 208-225 DOI: 10.1016/j.gca.2013.02.024

The Benefits of Current Mars Research

Image Credit: NASA

Image Credit: NASA

Martian exploration is unquestionably a hot topic right now. Mainstream media outlets have largely focused on the most visible efforts of the Curiosity mission, and that’s a good thing. While people might be thrilled with the photographs that they have an opportunity to view on their screens however, they may be less familiar with the implications of this research for the future.

For instance, previously little was known about how the Martian permafrost segments melted, and some researchers weren’t even convinced that significant melting occurred. Mars has no visible oceans, and that means that there really isn’t anywhere for huge amounts of fluid to flow. Thanks to current research efforts, data collected thus far has put together a more complete image of the melt patterns of sedimentary rocks on the Red Planet.

This data is useful in helpful in determining whether life once existed on Mars. While permafrost melt patterns aren’t really able to confirm or deny astrobiology theories, they’re an awfully good start. Although it’s not possible to determine if there were ever organisms that evolved as a result of these flows simply by looking at them, some researchers may argue that further probes are necessary to delve into this area further.

Outside of the search for life (current or prior) on Mars, the seasonal melting model also suggests that oceans could eventually be constructed on the planet. This is particularly exciting where terraforming projects are concerned. With stores of carbon dioxide readily available in the Martian atmosphere, it may be possible to produce something similar to a greenhouse effect. Once this occurs, plant life would be able to produce readily available supplies of oxygen (that stuff we humans need to live) while cooling off the planet in the process.

The research efforts currently under way may help scientists to determine more efficient methods of accomplishing this Martian overhaul. For instance, scientists currently know that seasonal melts could provide the necessary ingredients for seasons that are somewhat similar to those on Earth. Winter phases might be useful for helping to reduce the planets’ cooling process as well.

Tracking weather patterns on the Red Planet might also help researchers who would prefer to manipulate the Martian climate with lenses or shields. Once enough is known about weather and geological patterns on Mars, large lenses could be built in geostationary orbit. These would increase the amount of sunlight directed towards the planet. While engineers would have to be extremely careful not to pump dangerous levels of ultraviolet radiation towards colonists, these mirror systems might help to provide necessary light and heat for the planet once we’ve colonized the planet.

Detecting salt solutions have also helped researchers to better understand the chemical composition of the Martian surface. Industrial facilities may some day work mines on the planet to retrieve resources that are necessary to sustain human colonists. This could, in essence, create an economy on the planet. Additionally, as mineral resources continue to become increasingly rare on Earth, these materials could prove invaluable to future Earth-based citizens as well. Rovers actually prove that mining on Mars could probably be done with current technology – yet another benefit derived from current research efforts.

Few will deny that we are witnessing history almost daily as results from the Curiosity mission are released to the world. While this is without question an amazing time, I think it’s important that we recognize the amazing research being conducted in the process – research that could potentially impact the future of humanity in ways we are currently unable to understand.

Mars Earth comparison

Reference:

Peters, G., Smith, J., Mungas, G., Bearman, G., Shiraishi, L., & Beegle, L. (2008). RASP-based sample acquisition of analogue Martian permafrost samples: Implications for NASA’s Phoenix scout mission Planetary and Space Science, 56 (3-4), 303-309 DOI: 10.1016/j.pss.2007.10.001

Amato P, Doyle SM, Battista JR, & Christner BC (2010). Implications of subzero metabolic activity on long-term microbial survival in terrestrial and extraterrestrial permafrost. Astrobiology, 10 (8), 789-98 PMID: 21087159

Ridges on Mars Suggest Ancient Flowing Water

A 3-D image of an impact crater in the Nilosyrtis area on the Martian surface shows long pipe-like ridges, fossilized evidence of ancient subsurface water flow. Credit: NASA Mars Reconnaissance Orbiter

A 3-D image of an impact crater in the Nilosyrtis area on the Martian surface shows long pipe-like ridges, fossilized evidence of ancient subsurface water flow. Credit: NASA Mars Reconnaissance Orbiter

Networks of narrow ridges found in impact craters on Mars appear to be the fossilized remnants of underground cracks through which water once flowed, according to a new analysis by researchers from Brown University.

The study, in press in the journal Geophysical Research Letters (cited below) bolsters the idea that the subsurface environment on Mars once had an active hydrology and could be a good place to search for evidence of past life. The research was conducted by Lee Saper, a recent Brown graduate, with Jack Mustard, professor of geological sciences.

The ridges, many of them hundreds of meters in length and a few meters wide, had been noted in previous research, but how they had formed was not known. Saper and Mustard thought they might once have been faults and fractures that formed underground when impact events rattled the planet’s crust. Water, if present in the subsurface, would have circulated through the cracks, slowly filling them in with mineral deposits, which would have been harder than the surrounding rocks. As those surrounding rocks eroded away over millions of years, the seams of mineral-hardened material would remain in place, forming the ridges seen today.

Mineral deposits mark subsurface water flow A photo taken by the Mars Reconnaissance Orbiter shows ridges formed by fossilized subsurface water flow. Orientation of the ridges, mapped by researchers, is consistent with fractures formed by impact events. Credit: NASA and Mustard Lab/Brown University

Mineral deposits mark subsurface water flow
A photo taken by the Mars Reconnaissance Orbiter shows ridges formed by fossilized subsurface water flow. Orientation of the ridges, mapped by researchers, is consistent with fractures formed by impact events. Credit: NASA and Mustard Lab/Brown University

To test their hypothesis, Saper and Mustard mapped over 4,000 ridges in two crater-pocked regions on Mars, Nili Fossae and Nilosyrtis. Using high-resolution images from NASA’s Mars Reconnaissance Orbiter, the researchers noted the orientations of the ridges and composition of the surrounding rocks.

The orientation data is consistent with the idea that the ridges started out as fractures formed by impact events. A competing hypothesis suggests that these structures may have been sheets of volcanic magma intruding into the surrounding rock, but that doesn’t appear to be the case. At Nili Fossae, the orientations are similar to the alignments of large faults related to a mega-scale impact. At Nilosyrtis, where the impact events were smaller in scale, the ridge orientations are associated with each of the small craters in which they were found. “This suggests that fracture formation resulted from the energy of localized impact events and are not associated with regional-scale volcanism,” Saper said.

Importantly, Saper and Mustard also found that the ridges exist exclusively in areas where the surrounding rock is rich in iron-magnesium clay, a mineral considered to be a telltale sign that water had once been present in the rocks.

“The association with these hydrated materials suggests there was a water source available,” Saper said. “That water would have flowed along the path of least resistance, which in this case would have been these fracture conduits.”

As that water flowed, dissolved minerals would have been slowly deposited in the conduits, in much the same way mineral deposits can build up and eventually clog drain pipes. That mineralized material would have been more resistant to erosion than the surrounding rock. And indeed, Saper and Mustard found that these ridges were only found in areas that were heavily eroded, consistent with the notion that these are ancient structures revealed as the weaker surrounding rocks were slowly peeled away by wind.

Taken together, the results suggest the ancient Martian subsurface had flowing water and may have been a habitable environment.

“This gives us a point of observation to say there was enough fracturing and fluid flow in the crust to sustain at least a regionally viable subsurface hydrology,” Saper said. “The overarching theme of NASA’s planetary exploration has been to follow the water. So if in fact these fractures that turned into these ridges were flowing with hydrothermal fluid, they could have been a viable biosphere.”

Saper hopes that the Curiosity rover, currently making its way across its Gale Crater landing site, might be able to shed more light on these types of structures.

“In the site at Gale Crater, there are thought to be mineralized fractures that the rover will go up and touch,” Saper said. “These are very small and may not be exactly the same kind of feature we studied, but we’ll have the opportunity to crush them up and do chemical analysis on them. That could either bolster our hypothesis or tell us we need to explore other possibilities.”

Source: Elsevier

Reference:

Lee Saper, & John F. Mustard (2013). Extensive linear ridge networks in Nili Fossae and Nilosyrtis, Mars: Implications for fluid flow in the ancient crust Geophysical Research Letters : 10.1002/grl.50106

The Science of Choosing Space Pioneers

Image Credit: NASA Ames

Image Credit: NASA Ames

I often ask others if they would live in space or on another planet if given the opportunity. More often than not, the answer is in the affirmative. But what if you were given the chance and actually wanted to go, but were declined because you weren’t selected by a computer algorithm as one of the lucky space travelers? Or worse, what if you were declined because of your cultural background or because your genetic profile was deemed inappropriate?  What about those that do venture off to live in space or on other worlds…will they suffer the types of loneliness that individuals experience in major cities here on Earth today? These are the questions that I thought I’d delve into today.

Loneliness in Space

Overcrowding is a major concern in many parts of the world today. People often feel like they’re being shoved into boxes that they don’t really fit into. Since the early days of the Industrial Revolution, a great number of individuals have felt as if they are all alone in the world. Large cities don’t make for the best of neighbors. Even though other members of the human race surround people, they’re seldom able to make any genuine connections with those who live close by. This sort of a problem is only worsened by the prospect of space colonization.

The feeling of loneliness is usually portrayed as being experienced by those who are truly without anyone near them. However, individuals can actually become lonelier when other people that they don’t connect with show up within their circle of friends. Of course, in many cases, these people don’t even really have a circle of friends in the first place.

While one person adrift in space might be able to comfort him or herself with the idea that others are back home on planet Earth, ironically the same cannot always be said of someone who were to live in a colony habitat. If other people surrounded that same individual, he/she would probably end up experiencing increased feelings of loneliness — just as so many do in cities around the world today.

This is something that’s been observed by Earthbound psychologists for decades, but it would possibly worsen in orbital complexes and on colonized worlds. Sci-fi writers have long stressed the importance of choosing the right colonists for space missions based on genetic profiles. But it seems that culture and the ability to work together are actually more important indicators of who should go off together into the great unknown.

Un-natural Selection

Using some sort of computer algorithm to select candidates for space travel is probably the worst idea I can imagine. This is a common trope in many pieces of fiction, but engineers working on global cities might have actually found a better way to psychologically equip generations of space pioneers. They have suggested that those who are culturally similar to people they live with might very well make the best partners. Seems like common sense, right?

Source: NASA

Source: NASA

While this sounds reasonable, it opens up an entirely new thought process for those who are planning generational space missions. If colony ships are set out on extremely long voyages, people will want to be with those that they have bonded with or care about. Letting a community choose who they want to be with the same way that they always have on Earth might be the best idea.

Genetic selection might sound logical and some people have suggested that it could produce the best stock for other worlds. However, this is a throwback to the sort of eugenic thinking that predominated the early 20th century. It was a mistake here on Earth and the same holds true of space. If space colonies are ever actually going to solve population problems, they need to be able to function much like regular cities do today. By letting people live in space the same way that they always have on Earth, the average citizen is far more likely to adapt to others in an acceptable manner.

There are those who would say that this limits diversity, but in reality it doesn’t. Genetic selection programs and the like would actually seek to create a race of space colonists who are in some way similar to one another. This would limit diversity, and would also have the side-effect of making a civilization less resistant to disease or similar catastrophes. For instance, one colony of microbes could wipe out an entire colony if it were built in such a way. The same could be said of a generational space mission attempting to reach another star system.

Humanity has never been perfect. It is these imperfections that very well may help our species to survive in space in the future.

Reference:

Yusof, N., & van Loon, J. (2012). Engineering a Global City: The Case of Cyberjaya Space and Culture, 15 (4), 298-316 DOI: 10.1177/1206331212453676

Saaty, T., & Sagir, M. (2012). Global awareness, future city design and decision making Journal of Systems Science and Systems Engineering, 21 (3), 337-355 DOI: 10.1007/s11518-012-5196-z

ResearchBlogging.org

Are Rocks the Key to Finding Extraterrestrial Life?

While scientists like to bandy origin of life theories around, they seldom make the connection to astrobiological research. These theories, however, have a lot to suggest about how life may have developed on other worlds. According to recent studies, low-density vesicular volcanic rock material like pumice might have acted as something like a natural laboratory for chemical reactants that produced the so-called primordial soup. Early geological records show that pumice clasts were abundant in the approximate 3,460 Ma era period.

Samples collected from the Pilbara region in Western Australia exhibit signs of carbon. Traces of titanium oxide and iron sulfide were also found in the samples. Both of these are catalysts for certain reactions that suggest basic life processes. Other researchers have pointed to aluminosilicate minerals in the geological samples, which might be some sort of remains left by prokaryote life forms. Early prokaryotes might have colonized the clasts before they were buried, and therefore what scientists are currently examining are modified forms of what would have otherwise been regular rocks.

In any case, these are some of the earliest examples of life forms currently known to researchers. By examining these samples, it’s somewhat same to assume that a profile can be put together of what substances to look for when searching for remnants of life in astronomical materials. Asteroids are probably what have been covered the most in these studies, but they aren’t the only places to search. If a meteorite were to strike Earth that resembles these clasts, it would pretty exciting nevertheless.

When taking soil samples from other planets, researchers haven’t always been sure what they’re looking for. The Viking probes on Mars attempted to incubate microbes, and this proved relatively fruitless. However, future missions could instead try to locate geological samples that resemble those collected from the Pilbara region. There are plenty of samples in laboratory storage facilities anyway, and these could be examined without any real problems if permission could be granted to scientists.

That’s assuming that evolution takes an identical path on every planet. While some people might suggest this is a shortsighted way to look at the problem, it does have the benefit of making the fewest assumptions. Either way, there’s no reason not to take a look at existing rock samples to see if they match any of these chemical configurations. There’s little risk, and the benefit for a pretty impressive reward if successful.

Reference:

Martin D. Brasiera, Richard Matthewmana, Sean McMahonb, Matt R. Kilburnc, & David Wacey (2013). Pumice from the ∼3460 Ma Apex Basalt, Western Australia: A natural laboratory for the early biosphere Precambrian Research, 224, 1-10 : 10.1016/j.precamres.2012.09.008

ResearchBlogging.org

What Microfossils Found in Meteorites Can Tell Us

Photo of the martian meteorite ALH84001. Dull, dark fusion crust covers about 80% of the sample. Image Credit: NASA/JSC

While most people associate the term microfossil with the strange ALH 84001 object, there are plenty of other more concrete examples of tiny fossilized organisms. Research conducted with scanning electron microscope equipment has created a wide array of scientific literature regarding these small remains of living organisms. While marine objects don’t necessary have anything to directly do with the biogenic hypothesis of structures in meteorites, they do suggest that it’s possible for some meteorites to have remnants of antediluvian organisms.

This includes shergottite, nakhlite and chassignite meteorites that have come from Mars. It might be ironic that less attention is paid to Venus, when that planet is perhaps more like the Earth than Mars is. In fact, Venus is sometimes called Earth’s twin.

Structures resembling fossils make up the most solid body of proof for extraterrestrials. While research carried out by organizations like SETI isn’t usually accepted by mainstream academia, ALH 84001 showed up on the nightly news. These stories also illustrate the value of finding meteorite material on the Earth’s surface. Space exploration is a noble goal, but the process of recovering meteorites is far easier. It’s something that can be done immediately without any additional technology. That makes it a low hanging fruit for the hands of hungry scientific investigators.

Reference:

Emmanuelle J. Javaux, Craig P. Marshall, & Andrey Bekker (2010). Organic-walled microfossils in 3.2-billion-year-old shallow-marine siliciclastic deposits Nature, 463, 934-938 DOI: 10.1038/nature08793

Additional Learning Resources:

ResearchBlogging.org

Carbon Cycles in Extraterrestrial Atmospheres

A great deal of time is spent discussing the carbon cycle and what it means for the Earth’s climate. It seems that scientific journalists are very focused on issues surrounding the absorption of carbon. However, comparatively few people discuss what these theories could mean when applied to space exploration. Venus, for instance, lacks a natural carbon cycle. It currently lacks oceans, which means that no great carbon sink absorbs anything. There’s no biomass to take in gas either.

That doesn’t mean that humans couldn’t create one. Forests and reefs could be constructed over a long period of time to terraform the planet. While it would take decades, its not as unrealistic as one might think. Likewise, Mars could actually stand to benefit from the greenhouse effect.

As climatologists learn more about the Earth, they develop models that can be used to develop other planets. Nearly any terrestrial object in our solar system that has an atmosphere could be reshaped and used as a cradle for whatever life forms were deposited on it. Policymakers had better be sure that life doesn’t exist on a rock before attempting such a procedure, however. It’s better to be safe than sorry in that situation.